My understanding is that mono mode requires more current than 5A, since you are basically maxing out on the power of the TP3255. This is also why your stereo power rating is coming closer to the Aiyima and the chip specs, you are maxing out on voltage. The other consideration is the THD+N at 5W output into 4 ohms, which is pretty good and has been measured by ASR.
The manual which I read from says 315w x 1 at 48v/5a for 4 ohm. They also have it here: www.aiyima.com/products/aiyima-a07-max?variant=46847926239508 Scroll about halfway down and you’ll see a table that has a breakdown of the different power ratings with respect to power supply and load. They don’t provide a THD which this corresponds with, either. Also, the manual doesn’t show anywhere that it does 300 W into two channels. The highest it shows is 250 W. You can see this in the above link. This was my only real with the amplifier. The way it is marketed would make most consumers think that it would be a stereo amplifier with 300 W into each channel with some typical distortion value such as 1%. I’m getting about 160w @4 ohm with 48v/5a PSU. That’s really cool on its own. I just don’t appreciate the way it’s labeled as “300w+300w” when their own manual doesn’t even show that unless it’s an astronomical THD.
Here's the thing people don't seem to understand ... This is not an AB amplifier and you can't expect it to behave like one. The "mono" mode is not "Bridged" in the same way people are used to. In stereo the two channels are _already_ bridged. The term is BTL for Bridge Tied Load. In mono mode the chip is switched to PBTL which stands for Parallel Bridge Tied Load. At 8 ohms and 4 ohms _there is no increase in power_ . The parallel mode simply sinks current from both stereo channels to allow it to work with 3 and 2 ohm loads.
@@ErinsAudioCorner I agree that it is deceptive if they are advertising it as ~300 WPC (as opposed to the manual that no one reads before buying!). I am more familiar with the chip settings since I owned another Aiyima Amp. with the same chip in the past.
@@Douglas_Blake_579 Thank for the explanation, but I didn't mention the amp operating in BTL mode, nor I said anything about impedances, but about the actual demand that the chip imposes on the power supply, with 5A not quite enough in mono mode.
@@Douglas_Blake_579 I’m not sure of the relevance to this particular topic. I’m talking specifically about how this is advertised as “300+300”. Unless your comment wasn’t in reply to mine.
The high wattages are provided by TI's datasheet of the TPA3255 and measured at 10%THD+N: 315-W Stereo into 4 Ω in BTL Configuration 185-W Stereo into 8 Ω in BTL Configuration 600-W Mono into 2 Ω in PBTL Configuration Total Output Power at 1%THD+N (according to TI): 260-W Stereo into 4 Ω in BTL Configuration 150-W Stereo into 8 Ω in BTL Configuration 480-W Mono into 2 Ω in PBTL Configuration
@@steakhoux It's just better to assume the numbers are complete bullshit. It's a 100w amp, roughly. I don't care if my car makes 1000hp and it only survives one sprint down the track. I care if it's 100hp and I can do it all day every day.
2 important things to note about the TI ratings. 1. Those assume you've got all the input current in the world available, which is never true of these small cheap amps. 2. They're rating based on the total power input, not power output.
If with 48V PS it makes 100watts per channel into say 6-8ohms of clean low distortion (well below 1%) than it offers great value ... in small footprint for great convience and portability
My Cambridge amp was out for repair and I was told it would take at least four weeks for a new motherboard to arrive (warranty). So I purchased two of these Aiyima A07 max amps to fill in. There are being fed by a 30 year old Forte F45 preamp and driving my KEF LS 50 Metas. They sound very good. They reach the listening levels I am comfortable with and I'm not aware of any distortion. Very happy after two weeks.
@@TheMatsushitaManThank you!! It is very helpful to learn something important about a popular brand (more so when it’s a “well reputed” one) which you would probably never read in any review. Evidently they’re lower quality in durability, can you make any generalisations about their sound quality? Or do you know if it’s a similar situation with most popular mid-fi brands like Denon, Marantz, NAD? What would be immeasurably useful - are you aware of any websites where any this sort of information is shared? Cheers, Richard
If AVR manufactures would start putting full pre-outs on their low to mid range lineup again this would be a pretty good way to cheaply increase your power output on all channels versus built-in amps.
@@ups-pn3phEvery AVR should have at least 7 channel analog outputs, and ideally an analog output for every channel that it processes. It would make having to buy a new one every 3-4 years to have the newest format a lot more palatable if I was swapping out a 500$ piece of equipment with crap amplifiers instead of a 1500-2000$ piece of equipment with upgraded amplifiers I don’t need. Why this feature is withheld at the low end where it’s sorely needed is beyond me. At this point it’s smarter to just buy a higher end BD player with analog outs and skip the AVR altogether.
Erin. I appreciate your work. You are literally the best audio reviewer on the web. It's to to point that if you like something, I know I will too. Thanks.
Should keep in mind on those amps normally the used Chip (TPA3255) is a 4 channel chip capable of driving 4x 2ohm loads but in this case when used stereo channels 1/2 and 3/4 get bridged already making it a full bridge amp capable of driving two 4 ohm loads minimal, now when you go to full mono mode those two already bridged channels get paralleled up again shown as PBTL in the TPAs Datasheet making it capable of driving single 2 ohm load where you would get maximum potential going by your measurements about 350watts at 2ohm As we know when running somthing in parallel voltage doesn’t change just the current capabilities get increased so if you run full mono/PBTL mode at 4/8ohm you won’t expect much more power then running 2 channels each at 4/8ohm cause the voltage when paralleled stays the same, there may be a slight bit more power but that’s due to the channels sharing the load so each channel effectively sees 16ohm in 8Ohm PBTL mode or 8Ohm when in 4Ohm PBTL mode
I have twin A07's (not the max) running active to some home brew 2-ways using the Dayton 408 DSP. I did upgrade the preamps with some sparkos chips. Very happy with the performance of them.
I also use two A07s -- purchased four(!) years ago -- driven via a DSP-408 for the four ambience/surround speakers in my system. The DSP-408 is set up to correct a minor FR issue in those speakers as well as to compensate for the A07's output load dependence. I've never bothered with "op-amp rolling" -- too many $$ for little (if any) SQ difference IMO.
@@RobertCookcx -- You don't have to have "tried" a $2000 set of Michelins on your perfectly adequate little Toyota Corolla to sensibly infer that such a decision doesn't make a lick of sense. Between that and the fact that the supposedly deficient NE5532 is *still* to be found -- often in multiple dozens -- in some of the most acclaimed professional recording studio gear in the world told me all I need to know about the utter futility of the "op-amp swapping" phenomenon in the context of a sub-$100 "chip amp." YMMV, of course, and welcome to it! 😎
I literally searched your channel to see if you reviewed any Aiyima gear 2 days ago. Very pleased to see that the gods saw that VERY SPECIFIC part of my internet search history and blessed me with this. Have a good weekend!
I use two of the AO7 MAX in mono mode on my desktop with an smsl D6s DAC using my Atomamp+ headphone amp as a pre-amp. Speakers are somewhat hard to drive ELAC Unifi Reference. Extremely pleased. Quiet, clean, good strong bass control and as loud as I could ever want. I pledged on Kickstarter for the Fosi V3's, Duh, I think they'll go right to Ebay.
👍👍👍Kudos to Erin for taking the 300W+300W figures to task ! Habitually these tiny Class D "giants" claim a high output wattage at 4 ohms with a 10% THD. Why anyone would care about the amp's output at this astronomical distortion level is beyond me. All being said $75 for a well built desktop amp with 90wpc rms quality sound into 8 ohms is still a helluva bargain by any standard. Kudos to Aiyima and Fosi ! 👍👍👍
AIYMA - It is outright a lie and call this a 300/600w amplifier. It is all "marketing" nonsense. If they would advertise it as a 100w stereo amplifier, bridgeable, and leave it at that...then people (esp testers with calibrated test equipment) would say "wow". Instead, they open the rabbit hole of doubt, speculation, and disappointment. Still, for $75 with what it "can" do is pretty decent. Thanks for this video...solid presentation and facts!
Great review Erin. Having been a collector of expensive, midrange, and some lower level audio components for over a couple decades, my experience with these Chinese owned companies has not been stellar. I tried some of these devices out of curiosity. I had a Douk, Nobsound, stereo amplifier in 2021, and after gentle use the rear plastic auxiliary port just broke off completely, rendering the port useless. In 2022, I had the Fosi Audio, Box S2, phono preamplifier that failed right away after the first use. In 2022, I purchased the Aiyima, A08 Pro, stereo amplifier that played great for about 45 days of moderate usage then completely failed to make sound with both Bluetooth and auxiliary output. I’d say cool items that can sound good, but often lack total quality control. You pay for what you get in my experience.
@@literalghost929Fair question. I already have dozens of amplifiers. Most are not currently in use. I believe all but maybe one of them would out perform this amplifier. I appreciate the review and the tech.
I bought one of these to use while I wait for the V3 monos to ship. The Pascal module in my integrated amp got fried and it happened to coincide with the V3M Kickstarter, but I still needed a power amp in the meantime. In terms of sound and power, I’m sure I could cancel or sell the V3Ms and be just as happy keeping this in my system. But, I need a power amp and the lack of trigger or auto power-on is a bit of a deal-breaker with the A07 Max. Still, for the $73 I paid, I will definitely be holding on to it!
Good review - I like the measurements you're doing with these and the basic feedback, which seems to be that they sound the same to you. The real interesting thing to be about these would be, at decent listening levels (80-90db) how these compare to much more expensive amplifiers - and if they differ, why. There's a lot of "all amps sound the same" believers out there - I'm on the fence so listening tests like that are always interesting to me.
Thanks for the video review. Great job! I love these mini class D amplifiers. I currently use 1200W TPA 3255 2.1 dual amplifier board on 48V 10A power supply combined with cheap mini DSP Nvarcher and it's sound awesome! I measured the speaker and then room frequency response with UMIK-1 microphone and rew software and then I program the dsp to match my taste.
What do you mean by amplifier board? To me the Fosi and Ayima amps are just PCB boards. I have thought or stripping them from cases and mounting them on DIN rail box with a fan.
@@mattmiller4978 Class D amplifier boards TPA3255 and others usually comes stripped just like PCB sometimes with or without fan or with or without controls knobs or input and output connections. Mine does comes with the fan on it and controls knobs. There are many different options online.
@@pliedtkawell just watch Williston Audio labs video of the A07, with a 48v/5,2a powersupply (250watt) even on the amp dyno it did 170Watts per channel at 4 ohm clean and even 200watts burst which is more or less similar to a music signal that’s 340-400watts out of a 250watt powersupply so for sure the 1200watt amp board will do at least 600watts with that powersupply
Maybe this will help ... Power ... pretty simple a measurement of how much energy goes to the speakers. Frequency Response ... how evenly that power is distributed over the frequency range. (plus or minus 2db is considered inaudible) Distortion ... measures the difference between the input signal and the output to determine how much an amplifier changes it. (less than 0.5% distortion is considered inaudible) Noise ... how loud is that background hiss all amplifiers produce. (less than -80db will be inaudible in most rooms) SINAD ... Distortion + Noise (mostly useless but the higher the better)
From the video ... How do they make these things so cheap? Mass production, bulk purchasing, low parts counts, automated assembly, low labour costs... but dominantly, the total lack of the typical "audiophile markup". These guys aren't trying to get their year's income out of 150 units... they're selling literally tens of thousands of these every year so the cost of business is widely distributed across all of it.
Yes, it looks as though class D is cheaper to build and cheaper to transport too. It feels like the market is moving away from big A/B amps from big name brands. It will be interesting to see how fast.
@@10sassafras Laughably when I scan the online vendors to see what's new, the classic AB stuff doesn't come up until about 20 or 30 pages into the list. My best guess is that it's already happened and most audiophiles didn't even notice.
you hear people in the pro-audio world calling it "modern watts" when measuring class D amps and it's not what i thought. at first it seems a bit of tongue in cheek but i've looked into it and it's a legit way of measuring field/deployed max power in 'modern amps'. w/ traditional resistive load tests, comparing class AB to D max power is not an apples to apples comparison. long story short, they measure peak power in short bursts because apparently in real world situations as long as the amplifier's peak power sustain duration is longer than the peak attack duration of a sound being reproduced, that is enough to produce the advertised max average wattage -and the SPL meters do measure the amp's advertised max power. (a reserve vs demand scenario) class D is great at providing short bursts of high power but not great at sustaining that peak power, so the question is 'how long does the amp need to provide peak power to actually be louder?'... class AB pro amps can have identical max and peak power but at a lower value than class D burst peak... i've seen power density comparisons between AB and D class where the max voltages show class D under-performing while measured in resistive loads over a period of time (like automatically increasing a test signal until the amp reaches a preset distortion %), but the max and average power output w/ bursts or program content has the class D amps hitting the actual specification marks, far outperforming class AB in power density. i might be misremembering the numbers, but i think as long as the burst peak power duration is like 200-300ms, that's long enough for the measured average SPL to be in fact in agreement w/ the amp's wattage -even w/ bass heavy content such as dnb music. i'm not saying that is the case w/ this product, i'm just sharing something i've learned not long ago about the 'modern watts' and why pro class D amps seem to under-perform under traditional voltage tests but are right on the money in real world conditions. would be great to see the concept tested in the non-pro audio realm too...
The 300W was with a more powerful power source for the original A07 and you could choose separately which power adapter you wanted 48W being the highest. Yeah in the manual it lists the power sources and output power. The 32W 5A that it came with shows 78W @ 6ohm and 250w with a 48W 10A power adapter which is also 315W output in mono mode.
Hi Erin, some thoughts on distortion. I tend to not rate amplifiers at 1% THD. WHY? A 1%THD from a valve amplifier is quite normal. If you look at this THD on a scope the sine wave will not look distorted, or sound distorted. However, 1% distortion from a solid-state amplifier either class AB or D will look very distorted and sound dreadful simply because the THD content is CLIPPING and unusable power. I think maximum power should be rated NOT as a percentage but the maximum clean power just prior to clipping. Incidentally I have always used this way of rating on my channel, simply because it's honest. Who cares how much distorted or clipped power you can get. So, in this amplifiers case the 300 watts is in the real world 90 watts into 8 ohms. Still a respectable amount of power but a long way from 300 watts.
A 1% distortion "clipped signal" does not look as "clipped" as you might believe. Those huge clips we are used to see to show the concept of clipping only happen after more than 10% THD. I'm not sure a normal person would identify/detect a 0.001% signal vs a 1%. I mean, really. Side by side....mmm maybe, but if I show you one signal after the other you would not be able to see it. You would need to use zoom and scaling lines to see the difference; I mean the sinewave, not the FFT. But I agree that the clipping on Tube amps sounds not as harsh compared to class D amps.
I've got two of these and think they are brilliant. However, I've got the Fosi Audio V3 Mono on pre-order. Two main reasons: 1) The Fosi Audio auto shut off and start, which saves energy and reduces hear in my small office (these things run pretty hot) 2) The volume on each of my Aiyimas are not set the same so I've had to use a mic to match them. Not as important but 3) the Fosi Audio looks a bit better.
The "Auto" sense in the V3M is likely what killed the one Erin tested. What was likely happening is that he would be driving the amplifier into clipping for prolonged periods of time, getting the amplifier blistering hot. After a protection trip, if the auto function was on, the amplifier would sense incoming signal and turn itself right back on... and eventually it killed the amplifier. So, I will caution you not to use the auto function until you are absolutely sure you're not gong to get overtemperature trips on those little amplifiers. To avoid the excessive heating problem in what amounts to a fully enclosed case, I strongly suggest you do not use the 48 volt supplies with the V3M amplifiers and especially not the single 48 volt supply with the Y cable. The safe maximum would be dual supplies at 36 volts 5 amps, for each V3M.
@@Douglas_Blake_579 But I'm a) not going to be driving them as hard and for as long as Erin will be and b) Fosi Audio will continue to make adjustments to it product prior to release. I am thinking about switching from the dual power supply to the two single ones though.
@@c0mbat15 Absolutely use two single supplies. 36 volts 5 amps as recommended. The 48 to 36 volt loss is only about 2db and it's unlikely you would even notice that in normal listening. The sound quality is the same, but it reduces heat output substantially and will not thermal trip or jump to protection like the 48 volt would. My suggestion was to not use the "Auto" function until you are sure everything is working smoothly. Once you trust the setup, it's okay to turn it on. And no... you should never trust a manufacturer to do updates before release.
Thanks. Fosi Audio are very good and making updates and engaging with reviewers so I fully expect them to further iterate the product before release. There was already another defect that was found and they've committed to fixing it before release. They haven't managed to build their reputation over the past two years based on poor workmanship.
Thanks for the review Erin! Curious if you think testing it with an even lower ohm load makes sense, since quite a few bookshelves can hit close to 3 ohm. As in would the frequency response change even more for instance.
@@literalghost929 I had an old pair of Dynaudio Contour 1 MK2 that seemed to seriously overask a small fosi amp. According to docs they dipped to 3.2 ohm. I upgraded to an audio lab amp later, but initially fell for the 300 watt on 4 ohm lies.
I buyed one of this some days ago. I only listen death metal, black metal, thrash, speed metal, lp´s, cd´s, tapes demos, not good recordings and not clean productions, sometimes garage sounds, ok, this little amplifier´s sound is amazing with those recordings, i use an Arcam Delta 290 preamp with 8ohm 80´s Mourdant Short speakers but even with those recording types the sound is great. I think it is a very good option for entry level, yes the 300w power is vapor info, but for small rooms it´s an amazing option.
I would be impressed if I saw a small desktop amp that was advertised as 100watts @ 8ohm RMS for under $100. Unfortunately, Amazon's algorithm rewards dishonest specs for products on its site.
I can run my Maggie LRS+ with one Fosi ZA3, it does not even break a sweat, or even get warm. No issue cranking up the volume either, not that I listed to the Maggies at very high volume, I don't. So, your desktop speakers will be easily driven by one of these little amps. The clarity is very good, leans more Class A/B than typical Class D. For $100, these little amps are going to be hard to beat at this price point, you ought to try one. You measurement guys are missing out on some really decent and nice gear.
@@michaelwright1602 They're clearly a no brainer for price performance. It's crazy they can run Maggies, especially for the price... WHAT A TIME TO BE ALIVE!!
@@literalghost929 Totally impressed the hell out of me, one lone ZA3 drove them with ease. I have been on the fence with the V3 monos coming out, but will probably pull the trigger. My buddy put his ZA3 up against one of the latest Deer Creek Hypex amps he purchased a few weeks ago, around $1500 on their website... The stupid little Fosi sounded darn close in overall sound quality on his Fritz Carbon 7 Mk somethings... Around a $5000+ speaker pair, using a PS Audio DAC/Preamp. Yes, a good time to be alive in regards to audio.
Fosi V3 is 300W ~$100 with 48V power supply. ASR measured it: 4 Ohms measured 141 Watts. 8 Ohms measured 89 Watts, which is essentially the same as 100 Watts. Don't confuse the newer and fantastic TPA3255 chip with older TPA3116 chips, which were ok at best, definitely not great. So your comment would have been true a few years back, but today, quite a few options available which fit the bill!
Erin, I appreciate this review. I noticed in the data that the distortion does not increase as power decreases, one of the faults of many amplifiers on the market. I'd certainly be curious if differences could be heard with high efficiency speakers. Thx, Chris
These cheap but good class D amps are great for many use cases like just getting into the hobby, adding channels in a home theater, and DIY active loudspeakers.
I've been using them in my main system, driving various tower speakers, since the TPA3116 first appeared on the market. These are not beginner amps or even desktop amps. These are very capable amplifiers that use new technology.
How good is the audio quality though when compared to normal class AB amps? Schiit Vidar for instance is $800 bucks, probably similar power, how different do they sound?
In the wrong place buddy. Erin has made it clear many times bout this subjective diff. of amps thinking,, he says so in every video where he tests an amp and does ABX blind testing.
The AO7 Max and the Fosi ZA3 sound 2 dimensional vs the 3 dimensional sound of the better Class A/B amps. But, you get tighter bass, and a bit of sparkle in the higher end. Two totally different sounds, but neither one is bad. I have the Aiyima A07 Max, the Fosi V3 and the ZA3. They are all pretty close, but I prefer the ZA3 due to the XLR connections, just sounds a bit less Class D, and it easily drives my Maggies.
@@michaelwright1602 Thx! That pretty much exactly corresponds to my subjective experience with V3 vs class AB. But I haven't seen it translate or correspond in terms of measurements... Or does it? Which measurements would this correspond to?
Oh boy ... here we go again... First ... that A07Max will hit 300 watts ... at 10 % distortion. Even more in PBTL (mono) mode on a 2 ohm load. (using a 48 volt 10 amp bench supply) Now... look at the casing for that amplifier. This is a chip on the bottom design. But look at the ventilation they provide. Air intakes on the bottom, outlets on the sides. Open holes with no obstructions to convective cooling. Unlike their competition, they're not simply heating up the case. They are providing a way to get the heat out of the case as well. This is crucial to keeping things sane during prolonged loud sessions. Also, having done deep dives in both companies designs, I have found that Aiyima takes a lot more care in their designs. Overall these amps have better (cleaner) logic and pre-amp power supplies and they tend to have better protection circuitry as well. Now about this load dependency thing... With due respect to the measurement guys, this has to be the most overblown issue I've seen in a long long time. They are arguing about fractions of a decibel here... Elevate that to a normal listening level of 80db... those graphs represent about 79.5 db to 80.6 db variation ... *nobody* is going to actually hear that. Moreover; if they zoom out to show a full 80db spl, it would graph as a straight line. This is the royal tempest in a tea cup and it's about time to stop making such a big deal out of it. There is a deal breaker in this design: the power switch on the volume control. If you are running these as a dual monoblock setup, good luck re-balancing the sound every time you turn them on. Without a Trigger input, you're going to have a problem keeping your LR balance. Is this better than the V3, ZA3 or the V3M ... yes. Plain and simple. But for my money the original A07 is still the best of the bunch. All that said, this is still a very powerful chip in a remarkably small enclosure. To avoid thermal shutdowns, I recommend that you stick with 36 volt 5 amp power bricks.
I grabbed a couple of these. Guntar Smits Case with a TI INA 1650 preamp feeding an Icepoewer 125 ASX2 in bridged mode. 450 Watt monoblocks. ruclips.net/video/xhqybovCNjw/видео.html
Another mouth diarrhea explanation, on why these small class D amp are garbage. Both of these companies are total cat shit bad. None of the amps they make should ever make it’s way to any Americans house hold.
@@Eron55555 I see where you're going... Keep your A07m setup and look for a mid-price DAC... The big secret here is that there are actually $30.00 DACs out there using the same chipset as the $1,000 integrated amps. For USB from a PC or Phone do a search for (don't laugh now)... "Ding Shine D2 Mini" ... they can be had for $40.00 and when you open them up, you will find an advanced power supply, Sabre DAC chip and swappable op-amps. For Optical from a TV or DVD player... there are tons of adapters out there for less than $50.00 that will do a perfectly fine job. Really ... the truth is that cheap audio is getting better and better audio is getting cheaper. Soon they will merge.
Glad that you came out neutral about this despite preferring this over the Fossi. It speaks a lot about your recommendation, which, judging from your highly instruments-based conservatively impersonal analyses, actually I take it to be a positive and rave recommendation already 🤣. Now that you had your hands over this, I can rest easy that the two set I bought to drive mono L & R channels are well worth it, and that I can now spend my next five hundred dollars on a decent 6-inch++ bookshelves that I will pair with these awesome desktop amps 😬
Compared with others popular TPA3255 Fosi v3 stereo put an emphasis on the midrange, i would say it sounds opposite to V shape sound signature. On the ZA3 the midrange is more "tubey", without highlighting one register this amp is darker sounding and more "muddy" on human voices than the Ayima A07 MAX wich is way cheaper (paid 130€ on Ali for 2 units with 48v PS) and wich is wider soundstaging, more airy, punchier, cleared sounding and produce more bass. These sound reproduction differences are subtle. I recommand the Virtual Hifi channel for sound samples. I've bought two Aiyimas waiting for the Fosi V3 monoblocks arrive on the market but after i've read, watched the reviews available and listened to sound samples there is no interest to change for an other amp at the moment witch will just be a more expensive slightly different clone that will need an upgrade of 4 opamps versus 2 inside each unit, only the left channel each for the Aiyimas in mono mode. The stock opamps make these amps too dry sounding on the mids and highs for my taste in my system, with sibiliance on the voices and need an opamps upgrade. I bought two descrete Class A Akliam LC5 (only 12€ each) that need to use the amps without their cases and with dip8 risers or a modification by cutting on opening on the top of it. I don't feel the need to buy the expensive Sparkos opamp, these Akliams sound way better than others opamps i already owned and tried. I've sold my Atoll and my Marantz, i'm amazed how this configuration is stunning sounding with a Khozmo passive preamp and R2R DAC on my Proacs, detailed without to be fatiguing, without lacking lows, extra wide soundstaging and making humain voices natural sounding. I can't expect something better, after many changes it's the end of the pre/amplifier swapping game for me.
I believe that the Fosi amps have some decent caps and other components in them that are recognizable name brands. Not sure about the AIYIMA units. But I def. agree that the staggered outputs are nice.
This is the prove that Fosi's marketing about internal components had paid off. Aiyima also has the same quality Nichicon, Rubicon, Elna, WiMA capacitors, and Japanese inductors like Fosi. But I don't see Aiyima advertising it as a feature.
Thanks Erin! I was using a old Teac MC-D77 amp to power my desktop speakers until it stopped working this past February. After looking in to how I was going to replace it, I settled on the Aiyima A07. It works great for my desktop setup, and it's small enough where I have it sitting on the desktop as opposed to the side table I had to use for the Teac. Would I use it for my home theater system, no, but it's great for this application for sure. Looking forward to your review on the new SVS towers!
i have this amp and no channel imbalance issue at all .. i have already order a second one . i dont understand why amir even tested an obviously defected product or why he didnt ask for replacement in order to make a proper review . my bmw motorcycle came defective with a crack in motor block and after a month it was replaced with a new one by the authorized dealer . shit happens .. that does not mean that bmw's are not fine motorcycles .. i tend to believe that amir is a little biased to fosi stuff . anyway this amp sounds very good for what it is , is a multi purpose amp that can be used either with small desktop speakers or in main system with reasonably demanding floorstanders with a 48v meanwell psu . sound is dynamic even in low volumes and it can be really loud when you need . after a month i think even the 48v psu is an overkill in my main system 87db sensitivity two way floorstanders . i order the second one with a 36v psu . i really dont understand how anyone could not recommend the aiyima a07 max . it is a crazy deal . also i saw in another channel someone compares the aiyima and fosi with a naim supernait and this a joke also . i have listen for hours the first generation supernait with pmc speakers combo and there is no comparison . lets get serious neither fosi or aiyima can reach even close to that sound quality . My aiyima is very decent for what it is and it makes pointless to someone with about 400 euros budget look any further .. yes it is a giant killer from that point of view.
@@billkabbhello sir. what your speaker model? My spk is 4ohm 89db sensitive and i plant buy mono A07max to drive them. Should i go with 48v or 36v plug?
@@AnhNguyen-iw7cf dear friend my speakers are 8ohm and 87db sensitivity . i use a 36v 6a meanwell psu and the power is more than enough. i suggest you go with an external psu .. The psu has an adjustable output from 32v to 40v so you can choose what is best for you . also the quality is better than aiyima' s psu while price is almost the same. i live in a country with very hot summer so i like the option to adjust my psu at 32v for every day use and pump it to 40v only when it is necessary. even at 32v the a07max has plenty of power at 4ohms
@@AnhNguyen-iw7cf also the a07max need 2-3 weeks of burn-in period , it gets better over time so dont get rush to experiment with other opamps, ne5532 is good enough.
AMP video, I know.. sorry Erin but I have to ask; There's some fuzz around for Micca MB42-G2 (Passive), it seems the are the new ($99) best sound champ. I want them, but only if you review them.. any chance?...
Aiyima does what every other manufacturer does exaggerate the power rating. However I have had Fosi Audio amps and one of them had a huge channel imbalance so I returned it and at this point it seems Aiyima products are just built better and generally cost less Aiyima has a new Amplifier the A70 that is an PFFB amp that I am very interested in and might do a review of one at some point but Aiyima is taking their time releasing it and I think unlike Fosi they will wait till any bugs are worked out before shipping. If you watch Aiyima's videos showing the manufacturing of their products it's kind of impressive.
Sounds like with some pre-amp, and using the mono mode on the AO7 for ONLY a center channel between two towers, that has a nice adjustable separate channel EQ section, like the Marantz 11.2 chan flagship pre amp, a guy could dial in the spectrum wanted to match amp to a 4 Ohm HUNGRY center channel like a Theil CS2.2 center channel.
Bit late to the party... but I see nobody else has answered your question... I use these amps in "sound bar killer" setups for TV and HTPC use and have a couple of dozen of them out among friends and friends of friends. The setup I find most workable is this... 1) Turn your pre-amp (DAC, PC volume, etc,) up to maximum. 2) Turn the power amp gain up slowly until you find your max comfortable level and leav it there. (these little amps do get pretty darned loud) 3) Now in day to day use, use the pre-amp volume to control the actual listening level. This sort of gain staging usually ends up with nothing cranked to the limit and generally gives more control over the output, without driving things into clipping. In my day to day use, both volume controls end up about half way. Thus ... the cleanest sound. Hope that helps.
I haven't used the Fosi or Ayima amps, but i regularly use my Nobsound/Douk NS-04G PRO as a demo amp and just tried the NS-01G as part of a kit that i sold. Great little amps that sound clean and don't overheat with long usage
The models you named are both TPA3116 chips. These are a generation older than the TPA3255 chips these newer amps are using. And, believe me, the new chips are better.
I have a Nobsound (NS-10G) amp that I don't use because its components are badly isolated that the Bluetooth LED blinking actually introduces noticeable intermittent hiss in the signal which is especially noticeable if no music is playing. Nobsound: never again.
@@BillyGoatAudioInstalls NS-10G, and I should've clarified that it's not changing color but rather blinking. There's just a constant hiss in the Nobsound NS-10G by Douk Audio.
@@xavdeman by no means are these or the Ayima in the vid any kind of audiophile anything, and while i do include the little NS-01G in a "beginner/budget audiophile" package i make and sell, i don't inflate their abilities of compare them to "real" amplifiers
Can you explain how you performed the ABX test? Are you listening to a full song or a long complicated section, if so then it’s very difficult, even if there was a difference in actual levels.
@aeon7748 He is using the Van Alstine ABX Comparator device. Watch Erin's March 31st Livestream video that is titled, "Livestream: Taking Questions and Giving Names!"
3:51 - aux out is better than filtered sub out. just let subwoofer filter and phase for himself. 10:28 - so The Manual literally says it can deliver 315W with a 240W power supply ? ))) but for those who can read and count it's clear that this amp being about 80% efficient is 100+100W in stereo. (240/2)*0.8 = 96W
After watching your video, I have had to calculate the output power of my amp and it's maximum power supply voltage. It's nowhere near what sellers advertise it at. It's a class AB amp board with 8 transistors per channel and 40-0-40 voltage toroid. For power supply power, 40-0-40 is 80V which when rectified via full wave bridge rectifier produce around 85 volts DC. Based on cable thickness, the toroid can supply maybe 10 amps. Thus power supply can supply maximum of around 850 watts for both channels divide by two for each. As for maximum supply voltage that it can handle then we look at voltage rating of filter caps and power handling of transistors. Filter caps are rated for 100v which means supply voltage cannot exceed 100v. Each transistor can handle 100 watts continuous and 150 watts Max. For class AB there are pair of transistors one for swinging voltage on positive rail and another for swinging voltage on the negative rail. For class A amp, amplification happens on positive rail hence no PNP and NPN pairs are needed. What I am not sure about is if the power rating for the transistors is derived from multiplying each transistor power handling or multiplying by number of pairs. For my case, the transistors can handle a maximum of 800watts or 400 watts (I will need to research on power handling of transistor pairs) per channel which is no where near 1500 watts per channel some sellers advertise it at. To cut the long story short, for amp power rating, first look at the power supply watts or VA ratings. For DIY amps with separate power supply, check voltage ratings of filter caps and power handling of transistors or mosfets to get the maximum power supply VA that you can connect to the amp.
Easy way to test amplifier power ... 1) Hook up to a representative dummy load (8, 6, or 4 ohms). 2) Hook up to an oscilloscope to monitor the output. 3) Feed in a 1khz sine wave 4) Turn the amplifier up until the scope just shows clipping, then turn it down to just a hair below that point. 5) Using a volt meter check the AC RMS voltage across the speaker outputs. 6) Calculate as .... P = (E x E) / R For example 20 volts on 8 ohms ... P=( 20 x 20) / 8 = 400 / 8 == 50 watts. No need to get all lost in the guts, just measure it where it counts; at the output terminals.
Erin the PSU will tell the story. EG 32V 5A = 160MAX no matter how you slice it. I would rate a 32v5a rounding down. 30V×5A=150W×0.8max optimistic efficiency = 120W ÷ 2 stereo = 60W / channel MAX defined by physics.
I've got this amp, and a fozi audio BT20A pro. I mean they get the job done But I've never listened to a piece of audio equipment & been like... Wow, this is amazing! Most annoying things about it is when hooking up a sub, It just sends full blast signal out. It is not controlled with the volume., means you have to turn your sub up and down every time you touch the volume knob. Also, there's no crossover on the output. Should have a defeatable switch like 80 HZ or off for example. High pass on the mains would be great as well. Maybe I should just do reviews. If it can impress me, it'll impress anyone.
You need to use an active crossover, like the Rolls SX45, it is $109 and well worth the money. You cut the low frequency prior to getting to the amp, and shoot that to your sub(s). I would recommend getting one no matter what gear or amp you are using. The overall sound quality improvement is, and or can be, one of those rare OMG moments in audio, which are very rare.
I drive these with a minimum of 10A power supply. 10*50 = 500 W 5*48 = 240w of true power. Any power you're pulling past that is in the headroom of the power adapter in use. No way a 5a power supply can give you the headroom you need to drive clean power. As the chip uses current the power supply will not be able to keep up, resulting Vdrop on the power supply, it'll easily clip below the chips ability to drive the output circuit.
@uribar-ner5055 It will only overheat if its driving high power for an extended period and has no additional cooling. The higher current power supply will not hurt it, only give the chip the ability to use more current when needed and produce cleaner power.
I have bought 3 over the last 3 years, I gave the first one, a nobsound to my son for his shop system. I bought a Fossi Audio BT 10 a for my desktop system, then I recently purchased a Fossi audio bt20a pro for a portable system with a 12:29 pair of Klipsch b20 bookshelf speakers and it's the best sounding so far. I have no complaints and the value is obvious
It's not that you know you don't do that. It's that you can't know if you do that and thus the only reasonable assumption is that you would give it a favorable review, even if you think you don't. It's a psychological thing. I don't have a problem with it. I just think it's important to understand the problem.
That doesn’t really track, though. There isn’t any objective correlation with your statement. Just look at my previous review. Fosi sent me their amp and told me I could keep it and I marked the video as promotional. I wasn’t too enthusiastic about that one. I also buy things from time to time and give them poor reviews.
@@ErinsAudioCorner I think you're missing the point, which is a bit tricky. Even though it wasn't "too enthusiastic", it may have been a bit more so than you think you did. This is the insidious part of the issue. You think you're not, but you can't really know for sure. It's a well known function of Reciprocity bias . You perceive yourself as a neutral unconscious bias which is fallacious when you get "free stuff". Like I said, I still trust your review. But it's important to understand the problem. In other words, you say you're not biased, but it's complicated and no matter what you do, there is always that "Well he got it for free" problem. I don't think you're the other bozos in the review space. I think you are more trustworthy by a lot. As a reviewer you may think you'll be more critical of it because it's "free". Well... See... Now we're skewed the other way, maybe. See... It's no win when you get free stuff. So you have an issue where when you review stuff and they tell you to keep it, it puts you in a bad position. If it were me... I would tell them to send a return label with it because you can't keep it because it can and probably will skew your opinion. If they refuse, maybe the second best option is a give away right after and announce that on the video. Pain in the ass right? No good deed goes unpunished right? It's shitty I know. Otherwise, you may have to not review it if you truly wish to stay unbiased. The reality here is that the parent companies of these products are taking advantage of this problem with the "just keep it" thing, and it's at your expense. Again... I still trust your review, but it's important to understand the problem.
Erin I have a set of Bose acoustimass 3 with a Cambridge audio Azur 351A. I feel the Cambridge audio doesn't drive my speakers especially the bass. will something like the Aiyima do better?
Erin, question? I have three klipsch RP-280FA. I use two for left and right, can i use the third as my center channel? I can lay it flat under my projector screen!
Class D manufactures/assembler love to use those non sensical ratings kinda of 80s/90s PMPO ratings, That said, those little amps are awesome for what they are.
Just a suggestion Erin ... But you seem to be drawing a line between amplifiers that isn't actually there. You test on your Mofi speakers but still depict these amplifiers as "desktop" amps, following the mistaken notion that "smal amp == small speakers" and, with respect, that hasn't been true in over a decade. These little mini-amps are amplifiers, just like your "big boy amps". I have an A07 (original version) powering a pair of Pioneer towers in my living room. It's my main system and it's wonderful. I've sold a bunch of "Soundbar killers" with these mini-amps and a pair of tower speakers for use with TV sets and people are happy with them. So perhaps it's time to put that distinction to rest?
I think you’re drawing too much of a correlation in big speaker versus small amp. When I talk about a larger amplifier, I’m talking about one that has more output for larger distances and or higher dynamic range peaks. In many of these smaller amplifiers, I am limited and output at my typical listening distance.
@@ErinsAudioCorner As I said... only a suggestion. Maybe that's a flaw in your listening setup? I'm using an A07 (original) with a bit of case ventilation added with Pioneer tower speakers. On the rare occasion when I do turn things up, I've been heard 6 floors down in the building lobby... and in my apt. It's ear shattering loud (over 100db).
@@ErinsAudioCorner Second thought .... Are you sure you're getting full output from these amps in your listening room? What is not commonly discussed is that it takes about 2.5 volts to clip one of these amps on a 48 volt supply. Most "conventional" pre-amps only output about 1 volt (or less)... some DACs and CD players will produce 2 volts. So it's not uncommon these mini-amps are under-driven by some margin.
Man when these companies are going to start releasing GaN-FET amps for dirt cheap giving you clean 150w of power and good sound, we will be happy and able to spend most of our money on the better speakers ! Think about it, a 250w GaN-FET module with a decent power supply can be done for around 250 bucks. You buy two of those and for 500 you have great clean power on tap… can’t wait.
I have a little project for a garden. I already have some klipsch speakers and a marantz stereo amplifier but I need anothe amplifier to power two 12 inches and 250 watts subs, is this one a good option? I'm looking for an affordable option.
How are these Chinese amps so inexpensive? There is a manufacturing video on YT that shows how Fosi audio builds them. Most of the production is automated (not sweatshop slave labor) except for some of the final assembly. The stereo Texas Instruments Class D amp integrated circuit (TPA3255) that many of these amps are built around only cost about $5.00! This is just as much a TI innovation. The choice of high quality component parts rounds off some of these products, making them competitive. Yes, with a quality $5.00 chip, low prices are possible. Much of the specs of these amps come straight from the Texas Instruments data sheet.
The lack of true sub out and crossover is really holding these amps back. It would make them exponentially more usable. I have a Fosi V3 and it's great for what it is, but it's more of a novelty than a serious amp for critical applications. Being able to cut off the lows would surely benefit these things in the power department.
@@Douglas_Blake_579 That requires getting a separate preamp with crossovers and extra cables though. At that point you might as well move up to a more fully-featured amp or AVR, which would also probably be cheaper if bought used. I got tired of listening without a sub so I switched out the V3 with my old MIJ Denon AVR. More versatile and better in every way except size.
@@HarakiriRock Since most subs have their own built in crossovers, it could be as easy as a $30.00 passive volume control and a couple of Y adaptors. Total cost, maybe $50 with the extra cables.
I am wondering how these amps would measure if a HPF of 90Hz was applied to the mains so that they would not be hauling the low end load? Would it improve measurements?
Thanks Erin for the unbiased review. I bought the previous generation A07 just for grins to drive my heights in a 7.2.4 Atmos system as the AVR only had 9 channels of amplification. IT's been working great in that application for about a year. Like others stated - Texas Instruments spec's their TPA3255 at a stupidly obnoxious 10%THD+N for those high wattage numbers. Aiyima must think the buying public will digest those claims as it's from TI. I much prefer to see output level specs at 0.1%.
TI rates their chips in a mannor commensurate with other chip manufactuers. That is an "absolute maximum" rating that engineers use when designing safeguards into their products.
Could you suggest a good alternative to these, I'm thinking of Buying a JBL Stage A130 and 2 Aiyima A07 max or Fosi Za3 and could you give other alternatives
Will depend on how much you spend, lesser cost will not have that feature. If you are using separates, amp/preamp, pick up a Rolls SX45 active crossover, split the signal to the amp, and you will have the control you are looking for. They are $109 on Amazon and or Parts Express, worth every penny in my book. It will really change the way you listen to music, at least it did for me.
Fixed level, matching the input signal. It's a convenience output that can be used with a sub-woofer only if you have a source (PC, DAC, Streamer, Pre-Amp, etc) that includes volume control.
Thank you for this! I would like to ask the community of A07 Max owners If they know what the input impedance of this amplifier is? (aks input resistence = ratio of input voltage / Input current) thanks
Its a Class D -Class / A Hybrid Amplifier the best Mix from 2 Amp-Designs... Sounds warm like a Tube Amp with the power from Class D. Because runs hot like Class A. My Accuphase Sounds not better, because both are 100% of Sound ...😊
Your Amazon link says this unit is 230 Volts (AC). Isn't that for Europe or something? I'm afraid to buy it and plug it in to 110v. Am I missing something?
I have a dream... A 2.1 chip amp with integral power supply and real bass management. Whichever company brings out such a thing I believe will sell many of them. Maybe a bit larger than the brick powered chip amps so prevalent. Dayton has an amp with integral power supply but is lacking the whole package I dream of. Thanks for the freq response graphs. I've never seen such info on YT before.
@@aiyimaaudio8133 Well, since you asked, the Dayton DTA-100ST has an integral power supply, no separate power brick. AC house current directly into the amp. It has an adjustable high pass filter on the speaker outputs, with actual freq. numbers, always a plus. To use a subwoofer, it must be powered, and run off the Dayton's line out RCAs. So you have to crawl on the floor or reach between your legs to adjust the subwoofer low pass filter and volume. I have a Fosi BT30D Pro, which is a 2.1 amp with subwoofer level and low pass adjustment by unmarked knobs, and no L/R high pass. And a power brick. It's fine for low level bedroom fall asleep music. How about a 2.1 amp with integral power, both high and low pass adjustable filter knobs, with actual freq. numbers, RCA, BT and USB inputs. And line out for those with powered subs, with a low pass filter selectable on/off. This is proper bass management. Maybe throw in a remote. Is this too much to ask for? Do you not think it would sell? Thanks for asking.
@@aiyimaaudio8133 Try again. My dream, a 2.1 3 channel amp with high pass and low pass controls labelled with freq. numbers, integral power supply (no brick), and a line out for powered subwoofers. Usable with passive or powered subs. Real bass management. USB, BT and RCA input, and a remote. My dream.
A bit late but cannthis drive your average inefficient bookshelf that lists sensitivity at an optimistic 87db? Canbthis drive that speaker in a smallish room to over 85db? Hmmm. Maggies in mono mode???
THAT'S THE PROBLEM WITH ALL THIS...STUFF. WE HAVE NO-IDEA WHAT'S IN IT, WHO MADE IT (many times), HOW RELIABLE IT IS, AND WHETHER IT'S EVEN BACKED WITH SOME LEVEL OF SUPPORT. THIS IS WHY MOST SANE CITIZENS "STAY WITH" BRANDS THEY TRUST.
@@Douglas_Blake_579 they are much better in marketing than Aiyima, I have 3 fosi devices and 3 aiyima devices.... I prefer Aiyima in terms of sound and reliability... I got defective za3 xlr switch and once u open za3 to replace op Amps the volume knob gets broken
I have several TI 3255 amplifiers in the past. The Aiyima A07 was the first which I bought several years ago. I power it with a 450 watt 48 volt power supply. I primarily used it to drive a pair of vintage Genesys Physics II speakers that I use on my computer desk. The sound is fantastic. I have also tried The Fosi V3. For the price, these amplifiers are amazing. I also have a Stark Sound AD4. The Stark Sound AD4 has received fantastic reviews for its sound but critical reviews about its power output. Stark Sound also reported the amplifier at over 300 watts into 4 ohms. I believe that the power ratings are the ratings used by TI for the 3255. Here is what TI reports: • Total Output Power at 10%THD+N - 315-W Stereo into 4 Ω in BTL Configuration - 185-W Stereo into 8 Ω in BTL Configuration - 600-W Mono into 2 Ω in PBTL Configuration • Total Output Power at 1%THD+N - 260-W Stereo into 4 Ω in BTL Configuration - 150-W Stereo into 8 Ω in BTL Configuration - 480-W Mono into 2 Ω in PBTL Configuration • Advanced Integrated Feedback Design with High Please note that the power ratings are at 10%. This is certainly not listenable due to the high distortion -- however, if you can get 240 watts into 4 ohms with .1% percent and about 150 watts into 8 ohms with the same .1%. When we consider standard Class A/B amps, the amplifiers would clip very quickly after reaching the rail output voltage. The TI 3255 acts more like a tube in that rather than hard clip, it simply provides higher distortion. You wind up with a about 1 db or more overhead. The Stark Audio allows the user to run the amplifier in bridged mode which gives you more power into 4 ohms and 6 ohms. It doesn't do much for 8 ohms. I use the Stark AD4 with a pair of vintage EPI M400+. They drive them extremely well. I have compared them to a vintage Soundcraftsmen amplifier as well as a modern A/B amplifier and the TI 3255 does a very good job.
I think most people who have played around with these small amps have come to learn that while they are made with chip sets capable of 300 watts that is not the configuration they are sold as. Power out for these is linked to power in. Chip sets give a range of power that can be used but because of cost considerations manufacturers use a smaller power supply limiting severely their max output as sold. You can go out and purchase a larger brick power supply and get the 300 watts it's rated for but your likely to pay just as much as the price of the amp or more for it. So, the adds are generally misleading on these units relying that most don't know these facts. I think one company does supply the bigger power supply but can remember which one. It all comes back to buyer beware. And your reviews help those needing this information. So, your review just left out the why of the lower power measured. One thing might be important. If a user added the larger power supply the current unit might need additional heat remediation as it was not designed for higher power usage. Love your reviews.
When i first started watching ur vids i thought when you said toed out you ment literally aiming away to the back corners lol had my front sound stage sounding and looking so odd my gf even asked about it. I said the car audio bmx legend Erin said to do it and she apologized
That would be a "pink noise" test. Random frequencies at random amplitudes. I don't know if Erin does this but I will take an amplifier up to about 1% below clipping with pink noise for a couple of minutes to test for overheating.
Of course not ... that 300 number is the "absolute maximum" output spec from the "TPA3255 data sheet" ... do a search.... It will do it but it needs 48v 10 amps.
My understanding is that mono mode requires more current than 5A, since you are basically maxing out on the power of the TP3255. This is also why your stereo power rating is coming closer to the Aiyima and the chip specs, you are maxing out on voltage. The other consideration is the THD+N at 5W output into 4 ohms, which is pretty good and has been measured by ASR.
The manual which I read from says 315w x 1 at 48v/5a for 4 ohm. They also have it here:
www.aiyima.com/products/aiyima-a07-max?variant=46847926239508
Scroll about halfway down and you’ll see a table that has a breakdown of the different power ratings with respect to power supply and load.
They don’t provide a THD which this corresponds with, either.
Also, the manual doesn’t show anywhere that it does 300 W into two channels. The highest it shows is 250 W. You can see this in the above link.
This was my only real with the amplifier. The way it is marketed would make most consumers think that it would be a stereo amplifier with 300 W into each channel with some typical distortion value such as 1%. I’m getting about 160w @4 ohm with 48v/5a PSU. That’s really cool on its own. I just don’t appreciate the way it’s labeled as “300w+300w” when their own manual doesn’t even show that unless it’s an astronomical THD.
Here's the thing people don't seem to understand ...
This is not an AB amplifier and you can't expect it to behave like one. The "mono" mode is not "Bridged" in the same way people are used to.
In stereo the two channels are _already_ bridged. The term is BTL for Bridge Tied Load.
In mono mode the chip is switched to PBTL which stands for Parallel Bridge Tied Load. At 8 ohms and 4 ohms _there is no increase in power_ . The parallel mode simply sinks current from both stereo channels to allow it to work with 3 and 2 ohm loads.
@@ErinsAudioCorner I agree that it is deceptive if they are advertising it as ~300 WPC (as opposed to the manual that no one reads before buying!). I am more familiar with the chip settings since I owned another Aiyima Amp. with the same chip in the past.
@@Douglas_Blake_579 Thank for the explanation, but I didn't mention the amp operating in BTL mode, nor I said anything about impedances, but about the actual demand that the chip imposes on the power supply, with 5A not quite enough in mono mode.
@@Douglas_Blake_579 I’m not sure of the relevance to this particular topic. I’m talking specifically about how this is advertised as “300+300”. Unless your comment wasn’t in reply to mine.
The high wattages are provided by TI's datasheet of the TPA3255 and measured at 10%THD+N:
315-W Stereo into 4 Ω in BTL Configuration
185-W Stereo into 8 Ω in BTL Configuration
600-W Mono into 2 Ω in PBTL Configuration
Total Output Power at 1%THD+N (according to TI):
260-W Stereo into 4 Ω in BTL Configuration
150-W Stereo into 8 Ω in BTL Configuration
480-W Mono into 2 Ω in PBTL Configuration
That 600W can only work for very short bursts. With 90% efficiency this would generate about 60W of heat. Way to much for almost no cooling.
@@steakhoux It's just better to assume the numbers are complete bullshit. It's a 100w amp, roughly. I don't care if my car makes 1000hp and it only survives one sprint down the track. I care if it's 100hp and I can do it all day every day.
2 important things to note about the TI ratings.
1. Those assume you've got all the input current in the world available, which is never true of these small cheap amps.
2. They're rating based on the total power input, not power output.
If with 48V PS it makes 100watts per channel into say 6-8ohms of clean low distortion (well below 1%) than it offers great value ... in small footprint for great convience and portability
yes. buuuuut - they clearly stated in the manual that 300+300W are achievable with their default 240W (48x5) power supply )
I like that you’re reviewing and testing things at all price ranges. Thanks Erin!
My Cambridge amp was out for repair and I was told it would take at least four weeks for a new motherboard to arrive (warranty). So I purchased two of these Aiyima A07 max amps to fill in. There are being fed by a 30 year old Forte F45 preamp and driving my KEF LS 50 Metas. They sound very good. They reach the listening levels I am comfortable with and I'm not aware of any distortion. Very happy after two weeks.
Cambridge amps aren't built with very good components to begin with, unless you buy the flagship Edge series
@@TheMatsushitaMan I found this out the hard way. This is my 2nd time having a warranty repair.
@@TheMatsushitaManThank you!! It is very helpful to learn something important about a popular brand (more so when it’s a “well reputed” one) which you would probably never read in any review.
Evidently they’re lower quality in durability, can you make any generalisations about their sound quality? Or do you know if it’s a similar situation with most popular mid-fi brands like Denon, Marantz, NAD?
What would be immeasurably useful - are you aware of any websites where any this sort of information is shared?
Cheers, Richard
If AVR manufactures would start putting full pre-outs on their low to mid range lineup again this would be a pretty good way to cheaply increase your power output on all channels versus built-in amps.
@@ups-pn3phEvery AVR should have at least 7 channel analog outputs, and ideally an analog output for every channel that it processes. It would make having to buy a new one every 3-4 years to have the newest format a lot more palatable if I was swapping out a 500$ piece of equipment with crap amplifiers instead of a 1500-2000$ piece of equipment with upgraded amplifiers I don’t need. Why this feature is withheld at the low end where it’s sorely needed is beyond me. At this point it’s smarter to just buy a higher end BD player with analog outs and skip the AVR altogether.
Erin. I appreciate your work. You are literally the best audio reviewer on the web. It's to to point that if you like something, I know I will too. Thanks.
Use these with my Lintons. Bliss if you ask me. Brings em to life. I also found they brought my Elac UB52's alive as well.
Should keep in mind on those amps normally the used Chip (TPA3255) is a 4 channel chip capable of driving 4x 2ohm loads but in this case when used stereo channels 1/2 and 3/4 get bridged already making it a full bridge amp capable of driving two 4 ohm loads minimal, now when you go to full mono mode those two already bridged channels get paralleled up again shown as PBTL in the TPAs Datasheet making it capable of driving single 2 ohm load where you would get maximum potential going by your measurements about 350watts at 2ohm
As we know when running somthing in parallel voltage doesn’t change just the current capabilities get increased so if you run full mono/PBTL mode at 4/8ohm you won’t expect much more power then running 2 channels each at 4/8ohm cause the voltage when paralleled stays the same, there may be a slight bit more power but that’s due to the channels sharing the load so each channel effectively sees 16ohm in 8Ohm PBTL mode or 8Ohm when in 4Ohm PBTL mode
Thanks Erin. You are in the ultra rare ranks of reviewers who do blind testing. I value that.
I have twin A07's (not the max) running active to some home brew 2-ways using the Dayton 408 DSP. I did upgrade the preamps with some sparkos chips. Very happy with the performance of them.
I also use two A07s -- purchased four(!) years ago -- driven via a DSP-408 for the four ambience/surround speakers in my system. The DSP-408 is set up to correct a minor FR issue in those speakers as well as to compensate for the A07's output load dependence. I've never bothered with "op-amp rolling" -- too many $$ for little (if any) SQ difference IMO.
@@editorjuno Curious how you say you can't hear the difference of op amp upgrades if you never tried it?
@@RobertCookcx -- You don't have to have "tried" a $2000 set of Michelins on your perfectly adequate little Toyota Corolla to sensibly infer that such a decision doesn't make a lick of sense. Between that and the fact that the supposedly deficient NE5532 is *still* to be found -- often in multiple dozens -- in some of the most acclaimed professional recording studio gear in the world told me all I need to know about the utter futility of the "op-amp swapping" phenomenon in the context of a sub-$100 "chip amp."
YMMV, of course, and welcome to it! 😎
I literally searched your channel to see if you reviewed any Aiyima gear 2 days ago. Very pleased to see that the gods saw that VERY SPECIFIC part of my internet search history and blessed me with this. Have a good weekend!
I use two of the AO7 MAX in mono mode on my desktop with an smsl D6s DAC using my Atomamp+ headphone amp as a pre-amp. Speakers are somewhat hard to drive ELAC Unifi Reference. Extremely pleased. Quiet, clean, good strong bass control and as loud as I could ever want. I pledged on Kickstarter for the Fosi V3's, Duh, I think they'll go right to Ebay.
u can can cancel.
👍👍👍Kudos to Erin for taking the 300W+300W figures to task ! Habitually these tiny Class D "giants" claim a high output wattage at 4 ohms with a 10% THD. Why anyone would care about the amp's output at this astronomical distortion level is beyond me. All being said $75 for a well built desktop amp with 90wpc rms quality sound into 8 ohms is still a helluva bargain by any standard. Kudos to Aiyima and Fosi ! 👍👍👍
AIYMA - It is outright a lie and call this a 300/600w amplifier. It is all "marketing" nonsense. If they would advertise it as a 100w stereo amplifier, bridgeable, and leave it at that...then people (esp testers with calibrated test equipment) would say "wow". Instead, they open the rabbit hole of doubt, speculation, and disappointment. Still, for $75 with what it "can" do is pretty decent. Thanks for this video...solid presentation and facts!
Great review Erin.
Having been a collector of expensive, midrange, and some lower level audio components for over a couple decades, my experience with these Chinese owned companies has not been stellar. I tried some of these devices out of curiosity.
I had a Douk, Nobsound, stereo amplifier in 2021, and after gentle use the rear plastic auxiliary port just broke off completely, rendering the port useless. In 2022, I had the Fosi Audio, Box S2, phono preamplifier that failed right away after the first use. In 2022, I purchased the Aiyima, A08 Pro, stereo amplifier that played great for about 45 days of moderate usage then completely failed to make sound with both Bluetooth and auxiliary output.
I’d say cool items that can sound good, but often lack total quality control. You pay for what you get in my experience.
Thank you for sharing.
Great value for sure.
It actually does better than I expected.
Would I buy it? No.
Thank you for your detailed review and transparency
Why wouldn't you buy it?! lol
@@literalghost929Fair question. I already have dozens of amplifiers. Most are not currently in use. I believe all but maybe one of them would out perform this amplifier.
I appreciate the review and the tech.
Would this be a good amp to power my extra pair of Magnepan tweeters that drop to 3 ohms for super tweeter duty?
Check out the RSL class D amp. iA255. They have a sub out and a high pass filter switch.
I bought one of these to use while
I wait for the V3 monos to ship. The Pascal module in my integrated amp got fried and it happened to coincide with the V3M Kickstarter, but I still needed a power amp in the meantime.
In terms of sound and power, I’m sure I could cancel or sell the V3Ms and be just as happy keeping this in my system. But, I need a power amp and the lack of trigger or auto power-on is a bit of a deal-breaker with the A07 Max. Still, for the $73 I paid, I will definitely be holding on to it!
You can keep an eye on the A70.
Good review - I like the measurements you're doing with these and the basic feedback, which seems to be that they sound the same to you. The real interesting thing to be about these would be, at decent listening levels (80-90db) how these compare to much more expensive amplifiers - and if they differ, why. There's a lot of "all amps sound the same" believers out there - I'm on the fence so listening tests like that are always interesting to me.
Thanks for the video review. Great job! I love these mini class D amplifiers. I currently use 1200W TPA 3255 2.1 dual amplifier board on 48V 10A power supply combined with cheap mini DSP Nvarcher and it's sound awesome! I measured the speaker and then room frequency response with UMIK-1 microphone and rew software and then I program the dsp to match my taste.
48V and 10A, it might give 400W at best. How do they rate those chips🤔
What do you mean by amplifier board? To me the Fosi and Ayima amps are just PCB boards. I have thought or stripping them from cases and mounting them on DIN rail box with a fan.
@@mattmiller4978 Class D amplifier boards TPA3255 and others usually comes stripped just like PCB sometimes with or without fan or with or without controls knobs or input and output connections. Mine does comes with the fan on it and controls knobs. There are many different options online.
@@pliedtkawell just watch Williston Audio labs video of the A07, with a 48v/5,2a powersupply (250watt) even on the amp dyno it did 170Watts per channel at 4 ohm clean and even 200watts burst which is more or less similar to a music signal that’s 340-400watts out of a 250watt powersupply so for sure the 1200watt amp board will do at least 600watts with that powersupply
Not a big deal but it's already up to $91 as of 5/5/24 at 8:50AM EST. Love your honest and humble videos.
these stay right below the $75 price for amazon prime members.
I loved your explanation about measurements! I always have a hard time figuring out what the specs are saying
Maybe this will help ...
Power ... pretty simple a measurement of how much energy goes to the speakers.
Frequency Response ... how evenly that power is distributed over the frequency range. (plus or minus 2db is considered inaudible)
Distortion ... measures the difference between the input signal and the output to determine how much an amplifier changes it. (less than 0.5% distortion is considered inaudible)
Noise ... how loud is that background hiss all amplifiers produce. (less than -80db will be inaudible in most rooms)
SINAD ... Distortion + Noise (mostly useless but the higher the better)
Best bang for the buck hands down, i got 2 for duel mono, great sound !
From the video ... How do they make these things so cheap?
Mass production, bulk purchasing, low parts counts, automated assembly, low labour costs... but dominantly, the total lack of the typical "audiophile markup". These guys aren't trying to get their year's income out of 150 units... they're selling literally tens of thousands of these every year so the cost of business is widely distributed across all of it.
Yes, it looks as though class D is cheaper to build and cheaper to transport too. It feels like the market is moving away from big A/B amps from big name brands. It will be interesting to see how fast.
@@10sassafras
Laughably when I scan the online vendors to see what's new, the classic AB stuff doesn't come up until about 20 or 30 pages into the list. My best guess is that it's already happened and most audiophiles didn't even notice.
@@Douglas_Blake_579 Ali express cheap electronics are being flooded into the market.... Never heard of cheap products taking over any other markets.
Damn, maybe I should hunt for some second hand A/B classic before they become extinct. Or build one myself...
Your forgot low wages for their workers.
you hear people in the pro-audio world calling it "modern watts" when measuring class D amps and it's not what i thought.
at first it seems a bit of tongue in cheek but i've looked into it and it's a legit way of measuring field/deployed max power in 'modern amps'. w/ traditional resistive load tests, comparing class AB to D max power is not an apples to apples comparison.
long story short, they measure peak power in short bursts because apparently in real world situations as long as the amplifier's peak power sustain duration is longer than the peak attack duration of a sound being reproduced, that is enough to produce the advertised max average wattage -and the SPL meters do measure the amp's advertised max power. (a reserve vs demand scenario)
class D is great at providing short bursts of high power but not great at sustaining that peak power, so the question is 'how long does the amp need to provide peak power to actually be louder?'... class AB pro amps can have identical max and peak power but at a lower value than class D burst peak...
i've seen power density comparisons between AB and D class where the max voltages show class D under-performing while measured in resistive loads over a period of time (like automatically increasing a test signal until the amp reaches a preset distortion %), but the max and average power output w/ bursts or program content has the class D amps hitting the actual specification marks, far outperforming class AB in power density.
i might be misremembering the numbers, but i think as long as the burst peak power duration is like 200-300ms, that's long enough for the measured average SPL to be in fact in agreement w/ the amp's wattage -even w/ bass heavy content such as dnb music.
i'm not saying that is the case w/ this product, i'm just sharing something i've learned not long ago about the 'modern watts' and why pro class D amps seem to under-perform under traditional voltage tests but are right on the money in real world conditions. would be great to see the concept tested in the non-pro audio realm too...
Couldn't agree more
The 300W was with a more powerful power source for the original A07 and you could choose separately which power adapter you wanted 48W being the highest.
Yeah in the manual it lists the power sources and output power. The 32W 5A that it came with shows 78W @ 6ohm and 250w with a 48W 10A power adapter which is also 315W output in mono mode.
Actually the power levels advertised come from the "TPA3255 Spec Sheet" ... do a search.
Hi Erin, some thoughts on distortion. I tend to not rate amplifiers at 1% THD. WHY? A 1%THD from a valve amplifier is quite normal. If you look at this THD on a scope the sine wave will not look distorted, or sound distorted.
However, 1% distortion from a solid-state amplifier either class AB or D will look very distorted and sound dreadful simply because the THD content is CLIPPING and unusable power. I think maximum power should be rated NOT as a percentage but the maximum clean power just prior to clipping. Incidentally I have always used this way of rating on my channel, simply because it's honest. Who cares how much distorted or clipped power you can get. So, in this amplifiers case the 300 watts is in the real world 90 watts into 8 ohms. Still a respectable amount of power but a long way from 300 watts.
Agreed. You’ll notice that I mentioned the “knee” of the amps as well. 👍
A 1% distortion "clipped signal" does not look as "clipped" as you might believe. Those huge clips we are used to see to show the concept of clipping only happen after more than 10% THD. I'm not sure a normal person would identify/detect a 0.001% signal vs a 1%. I mean, really. Side by side....mmm maybe, but if I show you one signal after the other you would not be able to see it. You would need to use zoom and scaling lines to see the difference; I mean the sinewave, not the FFT.
But I agree that the clipping on Tube amps sounds not as harsh compared to class D amps.
Good Stuff Erin. Helps to have more clarity in this movement towards mini class D amps.
I've got two of these and think they are brilliant. However, I've got the Fosi Audio V3 Mono on pre-order. Two main reasons: 1) The Fosi Audio auto shut off and start, which saves energy and reduces hear in my small office (these things run pretty hot) 2) The volume on each of my Aiyimas are not set the same so I've had to use a mic to match them. Not as important but 3) the Fosi Audio looks a bit better.
The "Auto" sense in the V3M is likely what killed the one Erin tested.
What was likely happening is that he would be driving the amplifier into clipping for prolonged periods of time, getting the amplifier blistering hot. After a protection trip, if the auto function was on, the amplifier would sense incoming signal and turn itself right back on... and eventually it killed the amplifier.
So, I will caution you not to use the auto function until you are absolutely sure you're not gong to get overtemperature trips on those little amplifiers.
To avoid the excessive heating problem in what amounts to a fully enclosed case, I strongly suggest you do not use the 48 volt supplies with the V3M amplifiers and especially not the single 48 volt supply with the Y cable. The safe maximum would be dual supplies at 36 volts 5 amps, for each V3M.
@@Douglas_Blake_579 But I'm a) not going to be driving them as hard and for as long as Erin will be and b) Fosi Audio will continue to make adjustments to it product prior to release. I am thinking about switching from the dual power supply to the two single ones though.
@@c0mbat15
Absolutely use two single supplies. 36 volts 5 amps as recommended.
The 48 to 36 volt loss is only about 2db and it's unlikely you would even notice that in normal listening. The sound quality is the same, but it reduces heat output substantially and will not thermal trip or jump to protection like the 48 volt would.
My suggestion was to not use the "Auto" function until you are sure everything is working smoothly. Once you trust the setup, it's okay to turn it on.
And no... you should never trust a manufacturer to do updates before release.
Thanks. Fosi Audio are very good and making updates and engaging with reviewers so I fully expect them to further iterate the product before release. There was already another defect that was found and they've committed to fixing it before release. They haven't managed to build their reputation over the past two years based on poor workmanship.
@@c0mbat15
Actually they have.
Do a search for "The DB Pages music" and have a look at what I found in the TB10D.
Thanks for the review Erin! Curious if you think testing it with an even lower ohm load makes sense, since quite a few bookshelves can hit close to 3 ohm. As in would the frequency response change even more for instance.
Good question. I'd love to see it too, I think this is where those TPA amps might start to fail vs more expensive class AB amps
@@literalghost929 I had an old pair of Dynaudio Contour 1 MK2 that seemed to seriously overask a small fosi amp. According to docs they dipped to 3.2 ohm. I upgraded to an audio lab amp later, but initially fell for the 300 watt on 4 ohm lies.
I buyed one of this some days ago. I only listen death metal, black metal, thrash, speed metal, lp´s, cd´s, tapes demos, not good recordings and not clean productions, sometimes garage sounds, ok, this little amplifier´s sound is amazing with those recordings, i use an Arcam Delta 290 preamp with 8ohm 80´s Mourdant Short speakers but even with those recording types the sound is great.
I think it is a very good option for entry level, yes the 300w power is vapor info, but for small rooms it´s an amazing option.
I would be impressed if I saw a small desktop amp that was advertised as 100watts @ 8ohm RMS for under $100. Unfortunately, Amazon's algorithm rewards dishonest specs for products on its site.
Be impressed ... any amplifier with a TPA3255 chip is easily capable of 100 watts.
I can run my Maggie LRS+ with one Fosi ZA3, it does not even break a sweat, or even get warm. No issue cranking up the volume either, not that I listed to the Maggies at very high volume, I don't. So, your desktop speakers will be easily driven by one of these little amps. The clarity is very good, leans more Class A/B than typical Class D. For $100, these little amps are going to be hard to beat at this price point, you ought to try one. You measurement guys are missing out on some really decent and nice gear.
@@michaelwright1602 They're clearly a no brainer for price performance. It's crazy they can run Maggies, especially for the price... WHAT A TIME TO BE ALIVE!!
@@literalghost929 Totally impressed the hell out of me, one lone ZA3 drove them with ease. I have been on the fence with the V3 monos coming out, but will probably pull the trigger. My buddy put his ZA3 up against one of the latest Deer Creek Hypex amps he purchased a few weeks ago, around $1500 on their website... The stupid little Fosi sounded darn close in overall sound quality on his Fritz Carbon 7 Mk somethings... Around a $5000+ speaker pair, using a PS Audio DAC/Preamp. Yes, a good time to be alive in regards to audio.
Fosi V3 is 300W ~$100 with 48V power supply. ASR measured it: 4 Ohms measured 141 Watts. 8 Ohms measured 89 Watts, which is essentially the same as 100 Watts.
Don't confuse the newer and fantastic TPA3255 chip with older TPA3116 chips, which were ok at best, definitely not great.
So your comment would have been true a few years back, but today, quite a few options available which fit the bill!
Erin, I appreciate this review. I noticed in the data that the distortion does not increase as power decreases, one of the faults of many amplifiers on the market. I'd certainly be curious if differences could be heard with high efficiency speakers. Thx, Chris
These cheap but good class D amps are great for many use cases like just getting into the hobby, adding channels in a home theater, and DIY active loudspeakers.
I've been using them in my main system, driving various tower speakers, since the TPA3116 first appeared on the market. These are not beginner amps or even desktop amps. These are very capable amplifiers that use new technology.
What does that exactly mean; 'getting into the hobby'?
@@34332
Exactly ... what hobby?
Isn't this about putting together a decent sound system for music and movies. It's a purchase, not a personal quest.
@@Douglas_Blake_579
That sums it up nicely :)
@@Douglas_Blake_579 By hobby I meant continuously improving your stereo system over time. This is an audiophile themed video after all
How good is the audio quality though when compared to normal class AB amps? Schiit Vidar for instance is $800 bucks, probably similar power, how different do they sound?
In the wrong place buddy. Erin has made it clear many times bout this subjective diff. of amps thinking,, he says so in every video where he tests an amp and does ABX blind testing.
My A07 replaced a Marantz 6007 after about 20 seconds of listening.
I'll let you do the math on that one.
@@Douglas_Blake_579 A07 for 1/10th of the price is a no brainer if power output and sound is comparable 😂
The AO7 Max and the Fosi ZA3 sound 2 dimensional vs the 3 dimensional sound of the better Class A/B amps. But, you get tighter bass, and a bit of sparkle in the higher end. Two totally different sounds, but neither one is bad. I have the Aiyima A07 Max, the Fosi V3 and the ZA3. They are all pretty close, but I prefer the ZA3 due to the XLR connections, just sounds a bit less Class D, and it easily drives my Maggies.
@@michaelwright1602 Thx! That pretty much exactly corresponds to my subjective experience with V3 vs class AB.
But I haven't seen it translate or correspond in terms of measurements... Or does it? Which measurements would this correspond to?
Oh boy ... here we go again...
First ... that A07Max will hit 300 watts ... at 10 % distortion. Even more in PBTL (mono) mode on a 2 ohm load. (using a 48 volt 10 amp bench supply)
Now... look at the casing for that amplifier. This is a chip on the bottom design. But look at the ventilation they provide. Air intakes on the bottom, outlets on the sides. Open holes with no obstructions to convective cooling. Unlike their competition, they're not simply heating up the case. They are providing a way to get the heat out of the case as well. This is crucial to keeping things sane during prolonged loud sessions.
Also, having done deep dives in both companies designs, I have found that Aiyima takes a lot more care in their designs. Overall these amps have better (cleaner) logic and pre-amp power supplies and they tend to have better protection circuitry as well.
Now about this load dependency thing...
With due respect to the measurement guys, this has to be the most overblown issue I've seen in a long long time. They are arguing about fractions of a decibel here... Elevate that to a normal listening level of 80db... those graphs represent about 79.5 db to 80.6 db variation ... *nobody* is going to actually hear that.
Moreover; if they zoom out to show a full 80db spl, it would graph as a straight line.
This is the royal tempest in a tea cup and it's about time to stop making such a big deal out of it.
There is a deal breaker in this design: the power switch on the volume control. If you are running these as a dual monoblock setup, good luck re-balancing the sound every time you turn them on. Without a Trigger input, you're going to have a problem keeping your LR balance.
Is this better than the V3, ZA3 or the V3M ... yes. Plain and simple.
But for my money the original A07 is still the best of the bunch.
All that said, this is still a very powerful chip in a remarkably small enclosure. To avoid thermal shutdowns, I recommend that you stick with 36 volt 5 amp power bricks.
I think we are on the same page here.
I grabbed a couple of these. Guntar Smits Case with a TI INA 1650 preamp feeding an Icepoewer 125 ASX2 in bridged mode. 450 Watt monoblocks. ruclips.net/video/xhqybovCNjw/видео.html
Another mouth diarrhea explanation, on why these small class D amp are garbage. Both of these companies are total cat shit bad. None of the amps they make should ever make it’s way to any Americans house hold.
@@Eron55555
I see where you're going...
Keep your A07m setup and look for a mid-price DAC... The big secret here is that there are actually $30.00 DACs out there using the same chipset as the $1,000 integrated amps.
For USB from a PC or Phone do a search for (don't laugh now)... "Ding Shine D2 Mini" ... they can be had for $40.00 and when you open them up, you will find an advanced power supply, Sabre DAC chip and swappable op-amps.
For Optical from a TV or DVD player... there are tons of adapters out there for less than $50.00 that will do a perfectly fine job.
Really ... the truth is that cheap audio is getting better and better audio is getting cheaper. Soon they will merge.
@@ErinsAudioCorner
Good to hear.
Glad that you came out neutral about this despite preferring this over the Fossi. It speaks a lot about your recommendation, which, judging from your highly instruments-based conservatively impersonal analyses, actually I take it to be a positive and rave recommendation already 🤣. Now that you had your hands over this, I can rest easy that the two set I bought to drive mono L & R channels are well worth it, and that I can now spend my next five hundred dollars on a decent 6-inch++ bookshelves that I will pair with these awesome desktop amps 😬
Compared with others popular TPA3255 Fosi v3 stereo put an emphasis on the midrange, i would say it sounds opposite to V shape sound signature. On the ZA3 the midrange is more "tubey", without highlighting one register this amp is darker sounding and more "muddy" on human voices than the Ayima A07 MAX wich is way cheaper (paid 130€ on Ali for 2 units with 48v PS) and wich is wider soundstaging, more airy, punchier, cleared sounding and produce more bass. These sound reproduction differences are subtle.
I recommand the Virtual Hifi channel for sound samples.
I've bought two Aiyimas waiting for the Fosi V3 monoblocks arrive on the market but after i've read, watched the reviews available and listened to sound samples there is no interest to change for an other amp at the moment witch will just be a more expensive slightly different clone that will need an upgrade of 4 opamps versus 2 inside each unit, only the left channel each for the Aiyimas in mono mode. The stock opamps make these amps too dry sounding on the mids and highs for my taste in my system, with sibiliance on the voices and need an opamps upgrade. I bought two descrete Class A Akliam LC5 (only 12€ each) that need to use the amps without their cases and with dip8 risers or a modification by cutting on opening on the top of it. I don't feel the need to buy the expensive Sparkos opamp, these Akliams sound way better than others opamps i already owned and tried.
I've sold my Atoll and my Marantz, i'm amazed how this configuration is stunning sounding with a Khozmo passive preamp and R2R DAC on my Proacs, detailed without to be fatiguing, without lacking lows, extra wide soundstaging and making humain voices natural sounding. I can't expect something better, after many changes it's the end of the pre/amplifier swapping game for me.
I believe that the Fosi amps have some decent caps and other components in them that are recognizable name brands. Not sure about the AIYIMA units. But I def. agree that the staggered outputs are nice.
This is the prove that Fosi's marketing about internal components had paid off. Aiyima also has the same quality Nichicon, Rubicon, Elna, WiMA capacitors, and Japanese inductors like Fosi. But I don't see Aiyima advertising it as a feature.
Thanks Erin! I was using a old Teac MC-D77 amp to power my desktop speakers until it stopped working this past February. After looking in to how I was going to replace it, I settled on the Aiyima A07. It works great for my desktop setup, and it's small enough where I have it sitting on the desktop as opposed to the side table I had to use for the Teac. Would I use it for my home theater system, no, but it's great for this application for sure. Looking forward to your review on the new SVS towers!
With 48V/10A needs active-cooling..
but Sounds amazing.
Its quiet like the universe.❤
Thanks for a great review Erin. Did you notice a channel imbalance ? Amir didn't recommend this amp for that reason.
i have this amp and no channel imbalance issue at all .. i have already order a second one . i dont understand why amir even tested an obviously defected product or why he didnt ask for replacement in order to make a proper review . my bmw motorcycle came defective with a crack in motor block and after a month it was replaced with a new one by the authorized dealer . shit happens .. that does not mean that bmw's are not fine motorcycles .. i tend to believe that amir is a little biased to fosi stuff . anyway this amp sounds very good for what it is , is a multi purpose amp that can be used either with small desktop speakers or in main system with reasonably demanding floorstanders with a 48v meanwell psu . sound is dynamic even in low volumes and it can be really loud when you need . after a month i think even the 48v psu is an overkill in my main system 87db sensitivity two way floorstanders . i order the second one with a 36v psu . i really dont understand how anyone could not recommend the aiyima a07 max . it is a crazy deal . also i saw in another channel someone compares the aiyima and fosi with a naim supernait and this a joke also . i have listen for hours the first generation supernait with pmc speakers combo and there is no comparison . lets get serious neither fosi or aiyima can reach even close to that sound quality . My aiyima is very decent for what it is and it makes pointless to someone with about 400 euros budget look any further .. yes it is a giant killer from that point of view.
@@billkabbhello sir. what your speaker model? My spk is 4ohm 89db sensitive and i plant buy mono A07max to drive them. Should i go with 48v or 36v plug?
@@AnhNguyen-iw7cf dear friend my speakers are 8ohm and 87db sensitivity . i use a 36v 6a meanwell psu and the power is more than enough. i suggest you go with an external psu .. The psu has an adjustable output from 32v to 40v so you can choose what is best for you . also the quality is better than aiyima' s psu while price is almost the same. i live in a country with very hot summer so i like the option to adjust my psu at 32v for every day use and pump it to 40v only when it is necessary. even at 32v the a07max has plenty of power at 4ohms
@@AnhNguyen-iw7cf also the a07max need 2-3 weeks of burn-in period , it gets better over time so dont get rush to experiment with other opamps, ne5532 is good enough.
AMP video, I know.. sorry Erin but I have to ask; There's some fuzz around for Micca MB42-G2 (Passive), it seems the are the new ($99) best sound champ. I want them, but only if you review them.. any chance?...
Aiyima does what every other manufacturer does exaggerate the power rating.
However I have had Fosi Audio amps and one of them had a huge channel imbalance so I returned it and at this point it seems Aiyima products are just built better and generally cost less
Aiyima has a new Amplifier the A70 that is an PFFB amp that I am very interested in and might do a review of one at some point but Aiyima is taking their time releasing it and I think unlike Fosi they will wait till any bugs are worked out before shipping.
If you watch Aiyima's videos showing the manufacturing of their products it's kind of impressive.
Sounds like with some pre-amp, and using the mono mode on the AO7 for ONLY a center channel between two towers, that has a nice adjustable separate channel EQ section, like the Marantz 11.2 chan flagship pre amp, a guy could dial in the spectrum wanted to match amp to a 4 Ohm HUNGRY center channel like a Theil CS2.2 center channel.
Excellent overview, thank you for it. Would this amp be best turned full up and volume controlled via external preamp ?
Bit late to the party... but I see nobody else has answered your question...
I use these amps in "sound bar killer" setups for TV and HTPC use and have a couple of dozen of them out among friends and friends of friends.
The setup I find most workable is this...
1) Turn your pre-amp (DAC, PC volume, etc,) up to maximum.
2) Turn the power amp gain up slowly until you find your max comfortable level and leav it there. (these little amps do get pretty darned loud)
3) Now in day to day use, use the pre-amp volume to control the actual listening level.
This sort of gain staging usually ends up with nothing cranked to the limit and generally gives more control over the output, without driving things into clipping. In my day to day use, both volume controls end up about half way. Thus ... the cleanest sound.
Hope that helps.
I haven't used the Fosi or Ayima amps, but i regularly use my Nobsound/Douk NS-04G PRO as a demo amp and just tried the NS-01G as part of a kit that i sold. Great little amps that sound clean and don't overheat with long usage
The models you named are both TPA3116 chips. These are a generation older than the TPA3255 chips these newer amps are using. And, believe me, the new chips are better.
I have a Nobsound (NS-10G) amp that I don't use because its components are badly isolated that the Bluetooth LED blinking actually introduces noticeable intermittent hiss in the signal which is especially noticeable if no music is playing. Nobsound: never again.
@@xavdemanmodel? None of the Nobsounds i've seen have a color changing LED
@@BillyGoatAudioInstalls NS-10G, and I should've clarified that it's not changing color but rather blinking. There's just a constant hiss in the Nobsound NS-10G by Douk Audio.
@@xavdeman by no means are these or the Ayima in the vid any kind of audiophile anything, and while i do include the little NS-01G in a "beginner/budget audiophile" package i make and sell, i don't inflate their abilities of compare them to "real" amplifiers
Can you explain how you performed the ABX test?
Are you listening to a full song or a long complicated section, if so then it’s very difficult, even if there was a difference in actual levels.
@aeon7748
He is using the Van Alstine ABX Comparator device. Watch Erin's March 31st Livestream video that is titled, "Livestream: Taking Questions and Giving Names!"
3:51 - aux out is better than filtered sub out. just let subwoofer filter and phase for himself.
10:28 - so The Manual literally says it can deliver 315W with a 240W power supply ? )))
but for those who can read and count it's clear that this amp being about 80% efficient is 100+100W in stereo. (240/2)*0.8 = 96W
Just found your channel while looking for a small set of monitors. Realized you like bmx and reviewed Perlisten speakers. We have 2 things in common.
After watching your video, I have had to calculate the output power of my amp and it's maximum power supply voltage. It's nowhere near what sellers advertise it at. It's a class AB amp board with 8 transistors per channel and 40-0-40 voltage toroid. For power supply power, 40-0-40 is 80V which when rectified via full wave bridge rectifier produce around 85 volts DC. Based on cable thickness, the toroid can supply maybe 10 amps. Thus power supply can supply maximum of around 850 watts for both channels divide by two for each. As for maximum supply voltage that it can handle then we look at voltage rating of filter caps and power handling of transistors. Filter caps are rated for 100v which means supply voltage cannot exceed 100v. Each transistor can handle 100 watts continuous and 150 watts Max. For class AB there are pair of transistors one for swinging voltage on positive rail and another for swinging voltage on the negative rail. For class A amp, amplification happens on positive rail hence no PNP and NPN pairs are needed. What I am not sure about is if the power rating for the transistors is derived from multiplying each transistor power handling or multiplying by number of pairs. For my case, the transistors can handle a maximum of 800watts or 400 watts (I will need to research on power handling of transistor pairs) per channel which is no where near 1500 watts per channel some sellers advertise it at. To cut the long story short, for amp power rating, first look at the power supply watts or VA ratings. For DIY amps with separate power supply, check voltage ratings of filter caps and power handling of transistors or mosfets to get the maximum power supply VA that you can connect to the amp.
Easy way to test amplifier power ...
1) Hook up to a representative dummy load (8, 6, or 4 ohms).
2) Hook up to an oscilloscope to monitor the output.
3) Feed in a 1khz sine wave
4) Turn the amplifier up until the scope just shows clipping, then turn it down to just a hair below that point.
5) Using a volt meter check the AC RMS voltage across the speaker outputs.
6) Calculate as .... P = (E x E) / R
For example 20 volts on 8 ohms ... P=( 20 x 20) / 8 = 400 / 8 == 50 watts.
No need to get all lost in the guts, just measure it where it counts; at the output terminals.
P=V*I , so 48V with 5A will physically never be able to deliver 300W or more?
I think most folks know what the 3255 can do power wise by now.
Erin the PSU will tell the story. EG 32V 5A = 160MAX no matter how you slice it.
I would rate a 32v5a rounding down. 30V×5A=150W×0.8max optimistic efficiency = 120W ÷ 2 stereo = 60W / channel MAX defined by physics.
I've got this amp, and a fozi
audio BT20A pro.
I mean they get the job done
But I've never listened to a piece of audio equipment & been like... Wow, this is amazing!
Most annoying things about it is when hooking up a sub, It just sends full blast signal out. It is not controlled with the volume., means you have to turn your sub up and down every time you touch the volume knob.
Also, there's no crossover on the output. Should have a defeatable switch like 80 HZ or off for example. High pass on the mains would be great as well.
Maybe I should just do reviews.
If it can impress me, it'll impress anyone.
You need to use an active crossover, like the Rolls SX45, it is $109 and well worth the money. You cut the low frequency prior to getting to the amp, and shoot that to your sub(s). I would recommend getting one no matter what gear or amp you are using. The overall sound quality improvement is, and or can be, one of those rare OMG moments in audio, which are very rare.
@@michaelwright1602wait so high passing before signal hits the amp means low frequency content won’t hit your sub, which doesn’t really make sense?
I drive these with a minimum of 10A power supply. 10*50 = 500 W 5*48 = 240w of true power. Any power you're pulling past that is in the headroom of the power adapter in use. No way a 5a power supply can give you the headroom you need to drive clean power. As the chip uses current the power supply will not be able to keep up, resulting Vdrop on the power supply, it'll easily clip below the chips ability to drive the output circuit.
When running the a07max on 48v 10a power amp. Doesn't it get overheating? Aiyima doesn't recommend this.
@uribar-ner5055 It will only overheat if its driving high power for an extended period and has no additional cooling. The higher current power supply will not hurt it, only give the chip the ability to use more current when needed and produce cleaner power.
I have bought 3 over the last 3 years, I gave the first one, a nobsound to my son for his shop system. I bought a Fossi Audio BT 10 a for my desktop system, then I recently purchased a Fossi audio bt20a pro for a portable system with a 12:29 pair of Klipsch b20 bookshelf speakers and it's the best sounding so far. I have no complaints and the value is obvious
It's not that you know you don't do that. It's that you can't know if you do that and thus the only reasonable assumption is that you would give it a favorable review, even if you think you don't. It's a psychological thing. I don't have a problem with it. I just think it's important to understand the problem.
That doesn’t really track, though. There isn’t any objective correlation with your statement. Just look at my previous review. Fosi sent me their amp and told me I could keep it and I marked the video as promotional. I wasn’t too enthusiastic about that one. I also buy things from time to time and give them poor reviews.
@@ErinsAudioCorner I think you're missing the point, which is a bit tricky. Even though it wasn't "too enthusiastic", it may have been a bit more so than you think you did. This is the insidious part of the issue. You think you're not, but you can't really know for sure. It's a well known function of Reciprocity bias . You perceive yourself as a neutral unconscious bias which is fallacious when you get "free stuff". Like I said, I still trust your review. But it's important to understand the problem. In other words, you say you're not biased, but it's complicated and no matter what you do, there is always that "Well he got it for free" problem. I don't think you're the other bozos in the review space. I think you are more trustworthy by a lot.
As a reviewer you may think you'll be more critical of it because it's "free". Well... See... Now we're skewed the other way, maybe. See... It's no win when you get free stuff.
So you have an issue where when you review stuff and they tell you to keep it, it puts you in a bad position. If it were me... I would tell them to send a return label with it because you can't keep it because it can and probably will skew your opinion. If they refuse, maybe the second best option is a give away right after and announce that on the video. Pain in the ass right? No good deed goes unpunished right? It's shitty I know.
Otherwise, you may have to not review it if you truly wish to stay unbiased. The reality here is that the parent companies of these products are taking advantage of this problem with the "just keep it" thing, and it's at your expense.
Again... I still trust your review, but it's important to understand the problem.
Erin I have a set of Bose acoustimass 3 with a Cambridge audio Azur 351A. I feel the Cambridge audio doesn't drive my speakers especially the bass. will something like the Aiyima do better?
Erin, question? I have three klipsch RP-280FA. I use two for left and right, can i use the third as my center channel? I can lay it flat under my projector screen!
Class D manufactures/assembler love to use those non sensical ratings kinda of 80s/90s PMPO ratings, That said, those little amps are awesome for what they are.
I know you won't believe this but the ratings are honest RMS power.
Just a suggestion Erin ...
But you seem to be drawing a line between amplifiers that isn't actually there. You test on your Mofi speakers but still depict these amplifiers as "desktop" amps, following the mistaken notion that "smal amp == small speakers" and, with respect, that hasn't been true in over a decade.
These little mini-amps are amplifiers, just like your "big boy amps".
I have an A07 (original version) powering a pair of Pioneer towers in my living room. It's my main system and it's wonderful. I've sold a bunch of "Soundbar killers" with these mini-amps and a pair of tower speakers for use with TV sets and people are happy with them.
So perhaps it's time to put that distinction to rest?
I think you’re drawing too much of a correlation in big speaker versus small amp. When I talk about a larger amplifier, I’m talking about one that has more output for larger distances and or higher dynamic range peaks. In many of these smaller amplifiers, I am limited and output at my typical listening distance.
@@ErinsAudioCorner
As I said... only a suggestion.
Maybe that's a flaw in your listening setup?
I'm using an A07 (original) with a bit of case ventilation added with Pioneer tower speakers. On the rare occasion when I do turn things up, I've been heard 6 floors down in the building lobby... and in my apt. It's ear shattering loud (over 100db).
@@ErinsAudioCorner
Second thought .... Are you sure you're getting full output from these amps in your listening room?
What is not commonly discussed is that it takes about 2.5 volts to clip one of these amps on a 48 volt supply. Most "conventional" pre-amps only output about 1 volt (or less)... some DACs and CD players will produce 2 volts. So it's not uncommon these mini-amps are under-driven by some margin.
ASR admin's unit has a channel imbalance which doesnt seem to be tested here
Man when these companies are going to start releasing GaN-FET amps for dirt cheap giving you clean 150w of power and good sound, we will be happy and able to spend most of our money on the better speakers !
Think about it, a 250w GaN-FET module with a decent power supply can be done for around 250 bucks. You buy two of those and for 500 you have great clean power on tap… can’t wait.
I have a little project for a garden. I already have some klipsch speakers and a marantz stereo amplifier but I need anothe amplifier to power two 12 inches and 250 watts subs, is this one a good option? I'm looking for an affordable option.
nice. i’d like to buy this maybe but i don’t support / buy from amazon!
Lots of places to order these ... even WalMart online.
@@Douglas_Blake_579i’ll pass on walmart too lol. direct if available or i think if a big company then critchfiels is great.
How are these Chinese amps so inexpensive? There is a manufacturing video on YT that shows how Fosi audio builds them. Most of the production is automated (not sweatshop slave labor) except for some of the final assembly. The stereo Texas Instruments Class D amp integrated circuit (TPA3255) that many of these amps are built around only cost about $5.00! This is just as much a TI innovation. The choice of high quality component parts rounds off some of these products, making them competitive. Yes, with a quality $5.00 chip, low prices are possible.
Much of the specs of these amps come straight from the Texas Instruments data sheet.
The lack of true sub out and crossover is really holding these amps back. It would make them exponentially more usable. I have a Fosi V3 and it's great for what it is, but it's more of a novelty than a serious amp for critical applications. Being able to cut off the lows would surely benefit these things in the power department.
Use the A07 max as a power amp ... make your sub connections to a pre-amp.
@@Douglas_Blake_579 That requires getting a separate preamp with crossovers and extra cables though. At that point you might as well move up to a more fully-featured amp or AVR, which would also probably be cheaper if bought used. I got tired of listening without a sub so I switched out the V3 with my old MIJ Denon AVR. More versatile and better in every way except size.
@@HarakiriRock
Since most subs have their own built in crossovers, it could be as easy as a $30.00 passive volume control and a couple of Y adaptors. Total cost, maybe $50 with the extra cables.
@@Douglas_Blake_579 Still need a high pass for the mains though
@@HarakiriRock
Not really ... I've heard lots of systems running the LR mains full range. If properly adjusted it works well enough.
I had A07 and Fosi V3 side by side earlier but return A07 because it does not sound as good (to my ear).
May I use this Aiyima as a stereo power amp for my guitar cab? I mean... even If 50w per channel at 4ohms would be great
I am wondering how these amps would measure if a HPF of 90Hz was applied to the mains so that they would not be hauling the low end load? Would it improve measurements?
Thanks Erin for the unbiased review. I bought the previous generation A07 just for grins to drive my heights in a 7.2.4 Atmos system as the AVR only had 9 channels of amplification. IT's been working great in that application for about a year. Like others stated - Texas Instruments spec's their TPA3255 at a stupidly obnoxious 10%THD+N for those high wattage numbers. Aiyima must think the buying public will digest those claims as it's from TI. I much prefer to see output level specs at 0.1%.
TI rates their chips in a mannor commensurate with other chip manufactuers. That is an "absolute maximum" rating that engineers use when designing safeguards into their products.
Could you suggest a good alternative to these, I'm thinking of Buying a JBL Stage A130 and 2 Aiyima A07 max or Fosi Za3 and could you give other alternatives
Hello,
Any chance you can find some Audio Note speakers to test and review?
Did anyone try these amps using 48v 10a in mono mode?
Erin…’if you were’ in the market for a desktop amp….what exactly would you go for?
Just out of curiosity did you use the 48v 12a maxed out power supply required for max power
Do Denon, Rotel & Sony amps etc have a high pass on their sub outs?
Will depend on how much you spend, lesser cost will not have that feature. If you are using separates, amp/preamp, pick up a Rolls SX45 active crossover, split the signal to the amp, and you will have the control you are looking for. They are $109 on Amazon and or Parts Express, worth every penny in my book. It will really change the way you listen to music, at least it did for me.
Is the line output work with the volume knob or is it constant line level?
Fixed level, matching the input signal.
It's a convenience output that can be used with a sub-woofer only if you have a source (PC, DAC, Streamer, Pre-Amp, etc) that includes volume control.
Thank you for this! I would like to ask the community of A07 Max owners If they know what the input impedance of this amplifier is? (aks input resistence = ratio of input voltage / Input current)
thanks
These little amps run between 10k and 50k input impedances.
Any pre-amp, DAC, etc. should drive them very nicely.
Lol, in the title I read overheated instead of overrated 😂
Its a Class D -Class / A Hybrid Amplifier the best Mix from 2 Amp-Designs...
Sounds warm like a Tube Amp with the power from Class D.
Because runs hot like Class A.
My Accuphase Sounds not better, because both are 100% of Sound ...😊
Your Amazon link says this unit is 230 Volts (AC). Isn't that for Europe or something? I'm afraid to buy it and plug it in to 110v. Am I missing something?
The power bricks are dual voltage and will work on either, only the power cord is different.
I have a dream... A 2.1 chip amp with integral power supply and real bass management. Whichever company brings out such a thing I believe will sell many of them. Maybe a bit larger than the brick powered chip amps so prevalent. Dayton has an amp with integral power supply but is lacking the whole package I dream of.
Thanks for the freq response graphs. I've never seen such info on YT before.
Tell me more about it?
@@aiyimaaudio8133 Well, since you asked, the Dayton DTA-100ST has an integral power supply, no separate power brick. AC house current directly into the amp. It has an adjustable high pass filter on the speaker outputs, with actual freq. numbers, always a plus. To use a subwoofer, it must be powered, and run off the Dayton's line out RCAs. So you have to crawl on the floor or reach between your legs to adjust the subwoofer low pass filter and volume.
I have a Fosi BT30D Pro, which is a 2.1 amp with subwoofer level and low pass adjustment by unmarked knobs, and no L/R high pass. And a power brick. It's fine for low level bedroom fall asleep music.
How about a 2.1 amp with integral power, both high and low pass adjustable filter knobs, with actual freq. numbers, RCA, BT and USB inputs. And line out for those with powered subs, with a low pass filter selectable on/off. This is proper bass management. Maybe throw in a remote. Is this too much to ask for? Do you not think it would sell?
Thanks for asking.
@@aiyimaaudio8133 I did but my reply disappeared.
@@aiyimaaudio8133 Try again. My dream, a 2.1 3 channel amp with high pass and low pass controls labelled with freq. numbers, integral power supply (no brick), and a line out for powered subwoofers. Usable with passive or powered subs. Real bass management. USB, BT and RCA input, and a remote. My dream.
@@djg6015 Not yet, but stay tuned!
A bit late but cannthis drive your average inefficient bookshelf that lists sensitivity at an optimistic 87db? Canbthis drive that speaker in a smallish room to over 85db? Hmmm. Maggies in mono mode???
Nice but…. Does it SOUND good?
THAT'S THE PROBLEM WITH ALL THIS...STUFF. WE HAVE NO-IDEA WHAT'S IN IT, WHO MADE IT (many times), HOW RELIABLE IT IS, AND WHETHER IT'S EVEN BACKED WITH SOME LEVEL OF SUPPORT. THIS IS WHY MOST SANE CITIZENS "STAY WITH" BRANDS THEY TRUST.
what is an affordable amp with a high pass filter for the mains?
Did you see the new Fosi V3 monobloc
I have both A07max and 2 Za3 .....A07max sounds much better and better build quality as well .....fosi pays to reviewers to praise 👏 it😮
He tested both and didnt notice "a much better sound" but might agree bout the build quality.
Correct ...
But I don't think Fosi pays for praise. They are very clever marketing people, and for some reason buyers take it right in at face value.
@@Douglas_Blake_579 they are much better in marketing than Aiyima, I have 3 fosi devices and 3 aiyima devices.... I prefer Aiyima in terms of sound and reliability... I got defective za3 xlr switch and once u open za3 to replace op Amps the volume knob gets broken
I have several TI 3255 amplifiers in the past. The Aiyima A07 was the first which I bought several years ago. I power it with a 450 watt 48 volt power supply. I primarily used it to drive a pair of vintage Genesys Physics II speakers that I use on my computer desk. The sound is fantastic. I have also tried The Fosi V3. For the price, these amplifiers are amazing. I also have a Stark Sound AD4. The Stark Sound AD4 has received fantastic reviews for its sound but critical reviews about its power output. Stark Sound also reported the amplifier at over 300 watts into 4 ohms. I believe that the power ratings are the ratings used by TI for the 3255. Here is what TI reports:
• Total Output Power at 10%THD+N
- 315-W Stereo into 4 Ω in BTL Configuration
- 185-W Stereo into 8 Ω in BTL Configuration
- 600-W Mono into 2 Ω in PBTL Configuration
• Total Output Power at 1%THD+N
- 260-W Stereo into 4 Ω in BTL Configuration
- 150-W Stereo into 8 Ω in BTL Configuration
- 480-W Mono into 2 Ω in PBTL Configuration
• Advanced Integrated Feedback Design with High
Please note that the power ratings are at 10%. This is certainly not listenable due to the high distortion -- however, if you can get 240 watts into 4 ohms with .1% percent and about 150 watts into 8 ohms with the same .1%.
When we consider standard Class A/B amps, the amplifiers would clip very quickly after reaching the rail output voltage. The TI 3255 acts more like a tube in that rather than hard clip, it simply provides higher distortion. You wind up with a about 1 db or more overhead. The Stark Audio allows the user to run the amplifier in bridged mode which gives you more power into 4 ohms and 6 ohms. It doesn't do much for 8 ohms. I use the Stark AD4 with a pair of vintage EPI M400+. They drive them extremely well. I have compared them to a vintage Soundcraftsmen amplifier as well as a modern A/B amplifier and the TI 3255 does a very good job.
What a comprehensive share, love it!
I wish all reviews were as honest
I think most people who have played around with these small amps have come to learn that while they are made with chip sets capable of 300 watts that is not the configuration they are sold as. Power out for these is linked to power in. Chip sets give a range of power that can be used but because of cost considerations manufacturers use a smaller power supply limiting severely their max output as sold. You can go out and purchase a larger brick power supply and get the 300 watts it's rated for but your likely to pay just as much as the price of the amp or more for it. So, the adds are generally misleading on these units relying that most don't know these facts. I think one company does supply the bigger power supply but can remember which one. It all comes back to buyer beware. And your reviews help those needing this information. So, your review just left out the why of the lower power measured. One thing might be important. If a user added the larger power supply the current unit might need additional heat remediation as it was not designed for higher power usage. Love your reviews.
The power supply size is written clearly in the product manual.😃
Does the AUX port work when in mono mode?
Only the left end works in mono mode.
Could these be used as a subwoofer amp?
I wouldnt recommend it since the theres no active cooling aka fan on the amp.
Thanks
Not into the Patreon stuff, but I wanted to thank you this way for the wonderful content and the way you present it. I love your channel.
Wow. Thank you!
When i first started watching ur vids i thought when you said toed out you ment literally aiming away to the back corners lol had my front sound stage sounding and looking so odd my gf even asked about it. I said the car audio bmx legend Erin said to do it and she apologized
Hi Erin, any test for Amp to simulate the dynamism of the music? Ex: 13DR dynamic range test?
That would be a "pink noise" test. Random frequencies at random amplitudes.
I don't know if Erin does this but I will take an amplifier up to about 1% below clipping with pink noise for a couple of minutes to test for overheating.
A bit thin and bright. Noisy with 48v supply....gets fatiguing easily ...not a giant killer.
Class D sucks.
@@rking3724 not exactly....cheap class D sucks....I assure you TEAC HypexNcore and NAD purifi are well worth the cash.
@rking3724 not all .....teac hypexNcore and NAD purifi are very awesome
your amp is defective ask for replacement . probably fake or bad op-amps ..
@@billkabb no....comparing to real hi end amps....it is thin and bright...TEAC ap505...put it to shame.
I think the 3255 chip is game changer in hifi 😂
I don't think anyone expects this thing to do 300 watts with a 48v x 5 amp power supply.
Of course not ... that 300 number is the "absolute maximum" output spec from the "TPA3255 data sheet" ... do a search.... It will do it but it needs 48v 10 amps.