Heres the link to AudioScienceReview completed testing on the Fosi HD-A1. Results may not be pleasing but I still like thks amp. www.audiosciencereview.com/forum/index.php?threads/fosi-audio-hd-a1-budget-amplifier-review.14813/#post-461496
Sometimes distortion is intentional. That "warmth" you claim to hear isn't just in your head, that shows up on measurements. What did you expect? Perfectly transparent distortion tests? LOL
@@NATAWS9 Yes. I've seen tests of beloved vintage amps that have low SINAD. I know test results aren't everything, preference matters most and thats why I still like this amp for a warm thicker sound.
@@iowaudioreviews I like this amp as well. Different individuals have different preferences for artificial audio, I prefer warmer, less gritty. It is less fatiguing to me. I feel most audio enthusiasts overthink things sometimes.
I got one of these a day ago and have been listening to Tidal, SPotify with a Wiim, SMSL SU-8s DAC and JBL L52 Classics. I think it sounds pretty good. Better than a price and spec comparable AudioEngine N22. It drives the lower sensitivity L52s rather nicely. The amp is rather balanced and provides a bit more bass extension and firmness with the L52s. The mids and upper ranges are laid out smoothly with no lack of detail and nuance. Low volume jazz, chill and ambient electronica are smooth and present in a very natural manner. Nothing jumps out at you as being too forward or missing. Sound stage and imaging are spot on and do not hinder the JBLs at all.. The L52s sometimes sounded a little boxy on the N22 and on my budget tube amp they tend to get a little midrange forward on some modern material. My for first impressions the amp is well built, (quiet - not a hiss that I can hear) well behaved in presentation and certainly brings out the classic in the JBL L52 classics. As an alternative to Class D amps and a competitor to other Class AB analog amps I feel it plays well above its sub $200 pricetag. This amp will be playing long after the class D amps are taking up space in landfills. I dig the gold....sort of says "I am part of the new analog golden age"
After year, the FOSI HD-A1 has found its way into my living room. It runs adjacent my home theater system. I have a SMSL SU-8s DAC and a DOuk VU Meter switch speaker and amp switch box so I am able to share the AV fronts (Warhfedale 80th Dentons currently)....I really like how this amp performs. Listening to jazz high res master on Quboz with this stack is incredible. The sound stage is and imaging on this amp is nearly as good as my Schitt Gjarrahorn's running in mono. This amp really plays nicely with modern DACs and vintage voiced speakers. I don't use a sub with the Wharfedale Denton's I my 100 old house tends to bloom low resonant frequencies. So there is a native enhancement of the bass frequencies inherent in my living room. Such a unique and musical amp. I really enjoy Class AB amps.
As is usually the case, the Chinese will market the same amp under various names. This HD-A1 is marked by Aiyima, Breeze (BRZ), and several others , and when you research all of this on Alie Express, it makes you wonder who actually devise sand manufactures these amps? Of course, it's some unnamed OEM company and the end product is then marketed under a half dozen different brand names. Having said that, I ordered the Fosi HD-A1 off of the Fosi website a year ago (since Amazon were out of them). It arrived fairly quickly and when I attached everything (running KEF Q150 and Wharfedale D320 bookshelf speakers), the sound had that typical class AB signature - that is warmer than what you'd get with class D amps. I was quite the happy camper. I tested it with a variety of classical and jazz music - both large orchestra and smaller band varieties. It has excellent dynamic performance parameters, and the amp gets better as you warm it up. Typically, I don't pay attention much until the amp (or any other audio component for that matter) has been left on and running for 48 hours or so. But unfortunately, something happened after approximately 3 months, when the right channel began distorting - typically in the 500 - 1000 Hz range, noticeable with human voices and some instruments. It didn't occur until the amp was warmed up. At first, I assumed it was one of my other components, so I switched out many different components - but the same effect occurred. Then I switched out the Fosi HD-A1 with other amps I had on hand - several class AB models and several class D versions. The distortions were non-existent with those amplifiers, which told me it was the Fosi. Trying to communicate with Fosi (they are in China) was a nightmare. All they kept asking was, "can you send us a video of what you are talking about?" A video, I thought...what is that going to do - WTF? I explained in detail what my issues were, and the actions I used to test everything. I then also reminded them of their 18-month warranty - which didn't matter much. Then eventually asked me to check with the post office to see how much it would cost to send it back to them in China. The post office quoted me a cost of $83, and when I told Fosi this, they said that unfortunately, there was nothing they could do for me since it would be too expensive for them to have me ship it back to them. So keep this in mind when purchasing Fosi products. When they work - they work just fine. But if something goes wrong, forget about Fosi support helping you out of China.
Hi Bernd Herrmann, I have the same problems, developed within about the same time frame, as what you have mentioned here. If you find the solution or mods to this then please follow-up with an update. Thank you! : )
@@audiopolitan Unfortunately, unless you purchased the HD-A1 through Amazon (FOSI store on Amazon), you may be out of luck. As I mentioned, I went back and forth with Fosi support in China for a few weeks, and it ended with them saying that they can't help because it would be too expensive for them to pay for shipping back to China. I then - as a last resort - tried looking around my area for a reputable HIFI repair place, but couldn't find any (bummer again) - but even then, if I found one, the diagnostic costs alone would have been more expensive than I paid for the amp itself - not to mention the actual repair costs if they found the issue. So as it stands now, I have it sitting here in my home, in a box, and basically, it has become a paperweight. I had a 2nd (good working one) HD-A1, which I just sold to a nice gentleman in my area. As I said, when you have one that functions superbly (and after a longer period of time), then consider yourself lucky. But as of this writing, I've found no solution for the HD-A1 that has the right channel issues and as I said, it is now a paperweight. On another front, I just purchased (off of Amazon) the (so far) newly released, amazing Fosi T3 tube hybrid amp. It only costs $129 - yet has a superb sound signature with many audiophile qualities. It looks great and sounds wonderful. Let's see if it holds up long-term (still a bit guy shy about Fosi's HD-A1). Check it out on Amazon at this link: www.amazon.com/dp/B0B4W36C7B?psc=1&ref=ppx_yo2ov_dt_b_product_details
@@mohammedalomari1998The new Fosi ZA3 (and previous V3) are wonderful amps and they are now setting the standard for inexpensive amps. They are also more reliable and compact. I like the ZA3 better than I did the HD-A1.
I've had mine a few months now, and it sounds and looks awesome, I'm always messing around with new audio equipment so I added a Fosi Audio BR10C so I can play pretty much anything through it and I have Yamaha 115 wpc, Denon and Onkyo and the HD-A1 is the #1 Jewel out of them all.
Hey Eddie, quick question. I typically like bass and treble tone options on my amps. I'm hesitant to buy this amp, although I've been tempted, due to the lack of tone controls. Have you wished this unit had them? Any thoughts?
I love this amp. It's a toss up between the Emotiva a300. Both are great. I use this amp with my Jamo 803s. Or my JBL 530s. Both speakers are great also. I'm getting a Fluance RT81 turntable soon. 🙂
I use a good Fosi , updated power cord, to JBL 570. Great bass control, damped, fast, textured. Creamy, open mids, vocals in room! Hi's open, not as extended, Soundstage, depth, placement satisfying. Jfet warmth.
Currently, I am using JBL GX-A644SI car amplifier for my home audio with a 2.1 configuration. But it contains several wires, separate bluetooth module and separate big power supply. So for converting it to a compact one, can I use Fosi audio BT30D? I think the sound output power will enough with Fosi. But I am confused about the sound quality. Because JBL contains class AB amplifier while Fosi audio contains class D.
No way this is 50x2W as adversed,they sounds like 5 watt per channel in this video. I would like to know whats their estimated real power or how this thing can be louder for 8 ohm tower speakers
I just ordered the gold one before I realized they had a black one. Anyway, will this sound better than my vintage Crown D150A Amp I'm using now? Thanks.
It should be more musical but and little less powerful. The Crown D150A is a good amp but not built around fidelity but more for PA use. The HD-A1 has a nice warm musical tone which is kinda nice compared to many other amps I've tried that are nuetral and sterile sounding.
@@iowaudioreviews Thank you for your reply. I have a pair of Polk TSI300 floor standing speakers. My hopes is that if the first Fosi HD-A1 amp sounds as good as the reviews then I can bi amp them for more power. Thoughts on this?
Nice review 👌🏾plus looking forward to Amir detailed Audio Science Review testing, analysis, measurements. Only other review I've seen is by 2 Dudes Audio RUclips channel. My black Fosi Audio HD-A1 with UK AC220V-240V is getting delivered in two days time. Bought direct from the Fosi Audio site had $20 off the normal $199 price plus another 8% sign up discount. Worked out including delivery at only £173 total UK price, bargain for a Amp with these specs. The Fosi Audio guy Carlos was great emailed me straight after ordering asking if I had any questions. I will be using a very high quality performance power lead purchased from a well respected UK audio online store. Instead of the cheap stock power lead probably made for penny's that comes with it. Hooking it directly to just my trusty Oppo UDP 203 UHD blu ray player utilising the DAC from it. And new good quality bookshelf speakers sat on stands with added custom made thick highly absorbent acoustic open cell foam blocks. Can't wait to finally hear the Amp in my small living room system 🎶
@@iowaudioreviews hi thanks I saw the results on Audio Science Review yesterday. Unfortunately not very good measurements across the board. Still think it's a decent amp for the low £150 total I paid, nice warmth tube sound. But I've decided to get a new stereo amp 4x more expensive than the Fosi Audio HD-A1. Better quality as I want a accurate linear sound with nothing artificially added to the recording of music or movies. Class D with a decent low distortion low noise Hypex module and a better designed implemented internal power supply. Linear, transparent, detailed with a nice unusual half wooden half cnc machined aluminium case. Plus it's got bluetooth aptX so I can stream my music from my OnePlus 8 Pro phone.
How does this amp sound compared to some of the cheaper yet higher powered class d amps? I have their tda7498e amp and I'm wondering what about the sound is going to be improved by switching to class ab.
The Fosi Audio TDA7498e has much higher THD than the Fosi Audio HD-A1. It's still a decent amp for the cheap price but the specs for the HD-A1 blow it away in every department! Even the Fosi Amazon page says the HD-A1 is for high quality HiFi. My Fosi Audio HD-A1 arrives on Thursday. Will be hooking it directly to my Oppo UDP 203 4K blu ray player, using the DAC from it. Also will be replacing the stock Fosi power lead with a much better one performance wise and built quality wise.
Why pay 180 dollars for a mini amp that only puts out 50 watts per channel, when you can pay 150 dollars for a Sony STR-DH190 class A/B full size reciever with fm radio that puts out 100 watts per channel?
Why not, buy!? 50 watts is plenty, for what I use it for, an AMP. Don't need or use tuner/pre. Spkrs. JBL 570. Quality of wattage/FET sonics is superb. Transparent, see thru, open. Depth, soundstage. Quiet. Gold model. $150. A steal!!
I tried this amp with a couple of dacs, one using CS4398 and another AK4490. While it is warmer sounding than other amps, it tended to veil the sound and was far less resolving than an amp I compared and kept, an Aiyima A-04. So it affected the performance of the dacs in a negative way, IMO. For the price it's fine and if you like the sound, great. I would have kept it if it were more resolving with midrange and highs but keeping smoothness rather than veiling the sound, smoothing over the layers within music which are there. The Aiyima sounds better overall "to me" and allowed the dacs to shine in comparison. Also the Fosi hummed a bit and got significantly warmer going from 8 to 6 ohm speakers. Not sure if it could really handle 2 to 4 ohm loads.
N C everyone's equipment speakers, DAC, power leads, RCA interconnects etc, ears are different. What lacked detail to you in your system set-up could sound completely opposite in another person's system set-up. Looking online your one of only two people I saw saying the Fosi Audio HD-A1 sound signature is lacking detail. The majority said it has a good amount of detail in the sound produced. The Aiyima A-04 you prefer is a cheap class D amp. Average specs, has decent but not great reviews. Lots of people who own it say it has poor high distortion when played at over 70% volume. You can't expect miracles from the really cheap class D amps like the Aiyima A-04. The class AB Fosi Audio HD-A1 is much better spec wise including much lower THD and much better sound wise judging by the much better reviews from people online and on RUclips. My Fosi Audio HD-A1 arrives tomorrow. My bookshelf speakers, RCA interconnects, reference power cable and reference mains block definitely don't lack detail. Sometimes you need to upgrade improve the parts of your system that's lacking to get the best out of a amp. Most of the Amazon and Fosi site reviewers probably used the stock power lead that cost pennys supplied with the Fosi Audio HD-A1. Still got mostly great reviews nevertheless and considering the reasonable price though I always advise people to change stock lead to a good high quality power lead. It makes all the difference with the sound quality even with expensive Amps.
@@C--A I think I mentioned it was my experience. While the Fosi is well built, I tried three of the same amp, some variation in sound among them but all were more veiled compared to the Aiyima, at least to me. I guess I like detail and if there something to critique, well, that's also someone's prerogative. Yes, the Fosi produces more current, has more power, may even sound beefier, but they were all veiled, comparatively speaking. If I had to live with the Fosi, I could but would pair it with more revealing sources.
@@nc3419 everyone's ears and opinion of what they thinks sound good is different. But the Fosi Audio HD-A1 is definitely much better specced than the Aiyima A-04, that's a fact. Plus the majority of reviews online and this RUclips video and 2 Dudes Audio disagree with your opinion of the Fosi Audio HD-A1 being like a veil robbing details from the sound. Anyway enjoy the music as that's what matters most 🎶
Comparing it to my Emotiva A300 which is also a class AB amp they do sound similar where the Fosi is a bit warmer or softer and the Emotiva A300 is more neutral and detailed. Either way its fine people should pick the amp with a sound signature they like. Classic rock, blues or jazz is pretty sexy on the Fosi. Can't find the Aiyima A-04 for sale on Amazon or Ebay.
@@iowaudioreviews -- Yeah, but it doesn't deliver enough power to "Bass Shake" anything unless your listening space is in a phone booth, well under 50WPC into 4 ohms at 1 percent THD+N. My 20 year old Infinity active sub has 4x the power.
Your can a much better-performing -- 4x the power at 8 ohms and far lower THD+N -- Class D power amp and an appropriately beefy SMPS for half the price of this thing. Class AB no longer makes sense in limited-budget applications, where a properly designed amp built around a modern monolithic chip -- e.g. TI's superb TPA3255 -- can deliver incredible price/performance.
I've heard it mentioned that this amp generates a lot of physical buzz or hum from the transformer. Not through the speakers, just a buzz heard when you're in close proximity to the amp. Has anyone noticed that?
My black Fosi Audio HD-A1 AC220V-240V UK voltage version arrives in a couple of days. I have heard the gold coloured model produces more hum than the black coloured model. Also they say the hum is only there when Amp is powered on and no music playing. Once you play music the hum disappears completely. Im replacing the stock power lead with a very high quality high performance power lead that is meant to eliminate any electrical interference from the source and the mains. I'll report back later if I have any hum from my Fosi Audio HD-A1. My Amp is going in a AV unit so I likely won't notice the hum if I do have it.
Yes, obviously not as powerful as the A800 but at least for me it seems to have warmer sexier sound signature. I really enjoy listening to classic rock ,blues, jazz and some acoustic on this amp.
I actually had a set of these before I started my channel. They seemed to be good for the money and I used them for a few weeks then sold them to a friend. I'll ask my buddy if I can barrow them for a review.
When I first got this, I loved it but, all of a sudden I started getting static out of my speakers. I’ve done a lot of tracking to find the source and so far, it’s come down to the amp. Anyone else getting static through theirs?
@Thick Bad bitch Have a little more confidence in yourself. Just because your a stripper doesn’t mean your stupid! I did do a bit more detective work and found out what it was. I don’t like to use powered speakers for my computer so this is my computer amp. After I got a new computer, that’s when the static started. After much more detective work, I found it is the computer’s power supply. I bought a new one from a reputable company and installed it and no more static. It’s a shame that I had to spend another $100 on a power supply for a new computer that I only had for 3 months. Static is not covered under warranty so.........$$$
He's sending his Fosi Audio HD-A1 to Audio Science Review to do in depth measurements and analysis. Google Audio Science Review bookmark the site and check regularly to see when Amir reviews it. Audio Science Review don't have a RUclips channel. It's just a website where Amir tests speakers, amps, dacs etc. Lots of very clever forum members on it who are very knowledgeable regarding audio.
isn't it better to buy a car amplifier? those are cheaper, you will probably get more power for your money, they offer more options too like being bridgeable, hpf, lpf. I mean, $200 for what they say are 50W?? i am no giving away that money for that. there is this pioneer that for $65 gives you 60W rms at 4ohms and there are plenty of other options that will give you far more power and options than this thing for less money. we also have things like the Pioneer SX-10AE Home Audio Stereo Receiver that for less money gives you more power and options than this thing. just asking.
This amplifier isn't about power per dollar. If thats what your looking for, $200 will get you a nice used Crown, QSC or Behringer power amp. The Fosi HD-A1 was designed with sound quality and fidelity in mind, it will definitely sound better than anything you mentioned. Affordable car audio mostly consists of cheap class D amps that really don't have the power thay claim. The Fosi HD-A1 is 50w x 2 @8ohm and the Pioneer SX10AE is 45w x 2 @8ohm. The Pioneer has more options but I'd be willing to bet doesn't sound as good. A lot of this will depend on having good speakers and listening to a good audio source like CD or FLAC/WAV files. If all your music is just streaming or mp3 the SX10AE will be fine. Also watts don't work the way most people think. To go up 3db in volume which isn't much you have to double the power. So you really won't notice the difference between 100w and 125w, you would have to get up to 200w just to gain 3db. The problem is companies have been listing Max power on product for the last 30 years and people have gotten used to there usless high numbers thinking they need hundreds of whats when in reality 50w RMS or continuous is a good amount of power. Look at many vintage receivers from the 70s that are only 30 or 40w continuous power but could rock the whole house with a big set of speakers. One another note if you listen to mostly bass heavy music then you may want more power as lower frequencies take more power to push with clarity.
@@iowaudioreviews i am curious, why wouldn't the car amplifier sound as good as that amp? have you performed any testing? real testing. i am just wondering. wondering if paying all that money really get you all the magic people think are getting. i do not really need that much power, i just want good sound. when i look at those receivers from yamaha for example, they have so many inputs that i do not really need but are unable to play from usb nor do they have an equalizer plus the price is just insane on the basis of super special fidelity advertisement. i also only need stereo sound not 7.4.5.6.6.6...... speaker system. i know manufacturers usually pump the power really high and they now use peak power instead of the old PMPO. using a toroidal transformer won't make it really sound any better. what lies after the transformer is what will make the difference. they could have used switching power supply too.
@@iowaudioreviews 100% accurate! The Crown XLS series and the Behringer A800 Class D reference amps are a worthy mention...I do like this Fosi Audio HD-A1 very much, I bet it is every bit as good as it looks inside... TY for the review....it was real nice!
@@Billy-rr7re - Most car amplifiers are engineered to just be loud and push bass so they typically don't have the best specs when it comes to fidelity, lower SNR and higher THD. There are good car amps like JL Audio but $$$. Real testing would come down to numbers and most car amps at $180 don't have very impressive numbers other than watts. Granted most car amps are Class D and this Fosi is Class AB. Generally people favor Class AB amps for power and musicality but Class D is getting much better these days. Far as testing I mention in the video I will be sending this amp off to AudioScienceReview for professional testing. Once hes done with it I'll link the results in the comments. Now far as hearing a difference if you just listen to the radio, mp3 files or streaming services you probably wouldn't notice much difference in sound quality as those are all lower quality sources. Now if your primary source of music is vinyl, CD, FLAC or WAV files and you have good speakers the difference should be more noticeable. Not to mention in either situation you would want to use a decent DAC to get the best of the amplifier. When it comes to cost $200 is affordable for a amp of this quality. You don't have to spend a ton of money probably about $350 to get a system that can make a well recorded album almost seem magical. I may do a video in the future about using a car amp in the home.
I may have a APA150 in the future we'll see. I am familiar with it though. Comparing these two amps is apples to oranges when looking at who they were made for. The Fosi is basic affordable Hi-Fi and the Dayton is value with power/performance/versatility for an affordable price. After reading the APA150's test results from ASR it shows exactly that. I have sent the Fosi to ASR for testing so after the results are posted well at least see in numbers which is better. But my presumption is the Fosi will have better fidity but less power. The APA150 performed well enough to satisfy most people in its price range. Here's a link check out the review. Thanks for watching. www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-dayton-audio-apa-150-amp.6571/ On a side note two APA150 side by side in mono would be pretty cool BUT for the price a Crown XLS1002 or Behringer A800 would be better....idk.
De verdad que pesado...ábrelo de una vez!.La revisión podría haber durado 3 minutos...no mas!!.además se te escapa lo más relevante...lo siento no me gusta tu rewiev. El potenciometro , - que es lo que me interesaba - , es alps 16 o alps 27???
Heres the link to AudioScienceReview completed testing on the Fosi HD-A1. Results may not be pleasing but I still like thks amp. www.audiosciencereview.com/forum/index.php?threads/fosi-audio-hd-a1-budget-amplifier-review.14813/#post-461496
Sometimes distortion is intentional. That "warmth" you claim to hear isn't just in your head, that shows up on measurements. What did you expect? Perfectly transparent distortion tests? LOL
@@NATAWS9 Yes. I've seen tests of beloved vintage amps that have low SINAD. I know test results aren't everything, preference matters most and thats why I still like this amp for a warm thicker sound.
@@iowaudioreviews I like this amp as well. Different individuals have different preferences for artificial audio, I prefer warmer, less gritty. It is less fatiguing to me.
I feel most audio enthusiasts overthink things sometimes.
It is a darker sounding amp which holds back revealing dacs and speakers a bit. That rounding may be your preference but it wasn't mine.
You don't get a humm in yours? Replace those power caps I put 1500uf's in there you wont regret it ruclips.net/video/yt2nRl0KHJQ/видео.html
I got one of these a day ago and have been listening to Tidal, SPotify with a Wiim, SMSL SU-8s DAC and JBL L52 Classics. I think it sounds pretty good. Better than a price and spec comparable AudioEngine N22. It drives the lower sensitivity L52s rather nicely. The amp is rather balanced and provides a bit more bass extension and firmness with the L52s. The mids and upper ranges are laid out smoothly with no lack of detail and nuance. Low volume jazz, chill and ambient electronica are smooth and present in a very natural manner. Nothing jumps out at you as being too
forward or missing. Sound stage and imaging are spot on and do not hinder the JBLs at all.. The L52s sometimes sounded a little boxy on the N22 and on my budget tube amp they tend to get a little midrange forward on some modern material. My for first impressions the amp is well built, (quiet - not a hiss that I can hear) well behaved in presentation and certainly brings out the classic in the JBL L52 classics. As an alternative to Class D amps and a competitor to other Class AB analog amps I feel it plays well above its sub $200 pricetag. This amp will be playing long after the class D amps are taking up space in landfills. I dig the gold....sort of says "I am part of the new analog golden age"
After year, the FOSI HD-A1 has found its way into my living room. It runs adjacent my home theater system. I have a SMSL SU-8s DAC and a DOuk VU Meter switch speaker and amp switch box so I am able to share the AV fronts (Warhfedale 80th Dentons currently)....I really like how this amp performs. Listening to jazz high res master on Quboz with this stack is incredible. The sound stage is and imaging on this amp is nearly as good as my Schitt Gjarrahorn's running in mono. This amp really plays nicely with modern DACs and vintage voiced speakers. I don't use a sub with the Wharfedale Denton's I my 100 old house tends to bloom low resonant frequencies. So there is a native enhancement of the bass frequencies inherent in my living room. Such a unique and musical amp. I really enjoy Class AB amps.
As is usually the case, the Chinese will market the same amp under various names. This HD-A1 is marked by Aiyima, Breeze (BRZ), and several others , and when you research all of this on Alie Express, it makes you wonder who actually devise sand manufactures these amps? Of course, it's some unnamed OEM company and the end product is then marketed under a half dozen different brand names.
Having said that, I ordered the Fosi HD-A1 off of the Fosi website a year ago (since Amazon were out of them). It arrived fairly quickly and when I attached everything (running KEF Q150 and Wharfedale D320 bookshelf speakers), the sound had that typical class AB signature - that is warmer than what you'd get with class D amps. I was quite the happy camper. I tested it
with a variety of classical and jazz music - both large orchestra and smaller band varieties. It has excellent dynamic performance parameters, and the amp gets better as you warm it up. Typically, I don't pay attention much until the amp (or any other audio component for that matter) has been left on and running for 48 hours or so.
But unfortunately, something happened after approximately 3 months, when the right channel began distorting - typically in the 500 - 1000 Hz range, noticeable with human voices and some instruments. It didn't occur until the amp was warmed up. At first, I assumed it was one of my other components, so I switched out many different components - but the same effect occurred. Then I switched out the Fosi HD-A1 with other amps I had on hand - several class AB models and several class D versions. The distortions were non-existent with those amplifiers, which told me it was the Fosi.
Trying to communicate with Fosi (they are in China) was a nightmare. All they kept asking was, "can you send us a video of what you are talking about?" A video, I thought...what is that going to do - WTF? I explained in detail what my issues were, and the actions I used to test everything. I then also reminded them of their 18-month warranty - which didn't matter much. Then eventually asked me to check with the post office to see how much it would cost to send it back to them in China. The post office quoted me a cost of $83, and when I told Fosi this, they said that unfortunately, there was nothing they could do for me since it would be too expensive for them to have me ship it back to them.
So keep this in mind when purchasing Fosi products. When they work - they work just fine. But if something goes wrong, forget about Fosi support helping you out of China.
Hi Bernd Herrmann, I have the same problems, developed within about the same time frame, as what you have mentioned here. If you find the solution or mods to this then please follow-up with an update. Thank you! : )
@@audiopolitan Unfortunately, unless you purchased the HD-A1 through Amazon (FOSI store on Amazon), you may be out of luck. As I mentioned, I went back and forth with Fosi support in China for a few weeks, and it ended with them saying that they can't help because it would be too expensive for them to pay for shipping back to China. I then - as a last resort - tried looking around my area for a reputable HIFI repair place, but couldn't find any (bummer again) - but even then, if I found one, the diagnostic costs alone would have been more expensive than I paid for the amp itself - not to mention the actual repair costs if they found the issue.
So as it stands now, I have it sitting here in my home, in a box, and basically, it has become a paperweight. I had a 2nd (good working one) HD-A1, which I just sold to a nice gentleman in my area. As I said, when you have one that functions superbly (and after a longer period of time), then consider yourself lucky. But as of this writing, I've found no solution for the HD-A1 that has the right channel issues and as I said, it is now a paperweight.
On another front, I just purchased (off of Amazon) the (so far) newly released, amazing Fosi T3 tube hybrid amp. It only costs $129 - yet has a superb sound signature with many audiophile qualities. It looks great and sounds wonderful. Let's see if it holds up long-term (still a bit guy shy about Fosi's HD-A1). Check it out on Amazon at this link:
www.amazon.com/dp/B0B4W36C7B?psc=1&ref=ppx_yo2ov_dt_b_product_details
@@MrBenherrmann
Sorry to hear this about your fosi hd 1.
How you compare it new fosi hybrid amp?
Kind regard
@@mohammedalomari1998The new Fosi ZA3 (and previous V3) are wonderful amps and they are now setting the standard for inexpensive amps. They are also more reliable and compact. I like the ZA3 better than I did the HD-A1.
I've had mine a few months now, and it sounds and looks awesome, I'm always messing around with new audio equipment so I added a Fosi Audio BR10C so I can play pretty much anything through it and I have Yamaha 115 wpc, Denon and Onkyo and the HD-A1 is the #1 Jewel out of them all.
Hey Eddie, quick question. I typically like bass and treble tone options on my amps. I'm hesitant to buy this amp, although I've been tempted, due to the lack of tone controls. Have you wished this unit had them? Any thoughts?
This amp sounds warm and laid back. Its circuit is HDAM-based. There's also an HDAM-based A2 at nearly double the price of A1.
Lets leave class D for the computer nerds they dont love music anyway, they love chips.Audiophiles want toroidal transformers. I love this Fosi.
Thanks for your great channel and reviews
Do you consider this has the quality of tube sound?
Kind regards and best wishes
I love this amp. It's a toss up between the Emotiva a300.
Both are great. I use this amp with my Jamo 803s. Or my JBL 530s.
Both speakers are great also.
I'm getting a Fluance RT81 turntable soon. 🙂
I use a good Fosi , updated power cord, to JBL 570. Great bass control, damped, fast, textured. Creamy, open mids, vocals in room! Hi's open, not as extended, Soundstage, depth, placement satisfying. Jfet warmth.
Currently, I am using JBL GX-A644SI car amplifier for my home audio with a 2.1 configuration. But it contains several wires, separate bluetooth module and separate big power supply. So for converting it to a compact one, can I use Fosi audio BT30D? I think the sound output power will enough with Fosi. But I am confused about the sound quality. Because JBL contains class AB amplifier while Fosi audio contains class D.
*Correction* it has 2x Toshiba 2SC5200 and 2x Toshiba 2SA1943 output transistors. No 2SA1948.
No way this is 50x2W as adversed,they sounds like 5 watt per channel in this video. I would like to know whats their estimated real power or how this thing can be louder for 8 ohm tower speakers
I just ordered the gold one before I realized they had a black one. Anyway, will this sound better than my vintage Crown D150A Amp I'm using now? Thanks.
It should be more musical but and little less powerful. The Crown D150A is a good amp but not built around fidelity but more for PA use. The HD-A1 has a nice warm musical tone which is kinda nice compared to many other amps I've tried that are nuetral and sterile sounding.
@@iowaudioreviews Thank you for your reply. I have a pair of Polk TSI300 floor standing speakers. My hopes is that if the first Fosi HD-A1 amp sounds as good as the reviews then I can bi amp them for more power. Thoughts on this?
It's very clever how they used the aluminium chasis to cool the transistors :)
No, it's terribly obvious.
Sorry this video has lots of cuts. Tried getting it done early in the morning but my daughter woke up and yeah kids. Thanks for watching!
Nice review 👌🏾plus looking forward to Amir detailed Audio Science Review testing, analysis, measurements. Only other review I've seen is by 2 Dudes Audio RUclips channel. My black Fosi Audio HD-A1 with UK AC220V-240V is getting delivered in two days time. Bought direct from the Fosi Audio site had $20 off the normal $199 price plus another 8% sign up discount. Worked out including delivery at only £173 total UK price, bargain for a Amp with these specs.
The Fosi Audio guy Carlos was great emailed me straight after ordering asking if I had any questions. I will be using a very high quality performance power lead purchased from a well respected UK audio online store. Instead of the cheap stock power lead probably made for penny's that comes with it.
Hooking it directly to just my trusty Oppo UDP 203 UHD blu ray player utilising the DAC from it. And new good quality bookshelf speakers sat on stands with added custom made thick highly absorbent acoustic open cell foam blocks. Can't wait to finally hear the Amp in my small living room system 🎶
Did you send your Fosi Audio HD-A1 to Amir Audio Science Review? I'm very interested in the results of his measurements.
@@C--A I did, but I think since he started advertising his testing on the ASR website he's been swamped. Hope the results get posted soon .
@@iowaudioreviews hi thanks I saw the results on Audio Science Review yesterday. Unfortunately not very good measurements across the board. Still think it's a decent amp for the low £150 total I paid, nice warmth tube sound.
But I've decided to get a new stereo amp 4x more expensive than the Fosi Audio HD-A1. Better quality as I want a accurate linear sound with nothing artificially added to the recording of music or movies.
Class D with a decent low distortion low noise Hypex module and a better designed implemented internal power supply. Linear, transparent, detailed with a nice unusual half wooden half cnc machined aluminium case. Plus it's got bluetooth aptX so I can stream my music from my OnePlus 8 Pro phone.
How does this amp sound compared to some of the cheaper yet higher powered class d amps? I have their tda7498e amp and I'm wondering what about the sound is going to be improved by switching to class ab.
The Fosi Audio TDA7498e has much higher THD than the Fosi Audio HD-A1. It's still a decent amp for the cheap price but the specs for the HD-A1 blow it away in every department! Even the Fosi Amazon page says the HD-A1 is for high quality HiFi.
My Fosi Audio HD-A1 arrives on Thursday. Will be hooking it directly to my Oppo UDP 203 4K blu ray player, using the DAC from it. Also will be replacing the stock Fosi power lead with a much better one performance wise and built quality wise.
I have/use an upgraded 1 m power cord, 12 gauge. Works fine. Sound? IDK!?...😯😯
Why pay 180 dollars for a mini amp that only puts out 50 watts per channel, when you can pay 150 dollars for a Sony STR-DH190 class A/B full size reciever with fm radio that puts out 100 watts per channel?
Why not, buy!? 50 watts is plenty, for what I use it for, an AMP. Don't need or use tuner/pre. Spkrs. JBL 570. Quality of wattage/FET sonics is superb. Transparent, see thru, open. Depth, soundstage. Quiet. Gold model. $150. A steal!!
Is this an NAP250 clone?
Do you miss bass and treble controls?
Nope! Don't need or use. Not that type of 'phile. 😬😬
Cool amp and video!!!
I tried this amp with a couple of dacs, one using CS4398 and another AK4490. While it is warmer sounding than other amps, it tended to veil the sound and was far less resolving than an amp I compared and kept, an Aiyima A-04. So it affected the performance of the dacs in a negative way, IMO. For the price it's fine and if you like the sound, great. I would have kept it if it were more resolving with midrange and highs but keeping smoothness rather than veiling the sound, smoothing over the layers within music which are there. The Aiyima sounds better overall "to me" and allowed the dacs to shine in comparison.
Also the Fosi hummed a bit and got significantly warmer going from 8 to 6 ohm speakers. Not sure if it could really handle 2 to 4 ohm loads.
N C everyone's equipment speakers, DAC, power leads, RCA interconnects etc, ears are different. What lacked detail to you in your system set-up could sound completely opposite in another person's system set-up. Looking online your one of only two people I saw saying the Fosi Audio HD-A1 sound signature is lacking detail. The majority said it has a good amount of detail in the sound produced.
The Aiyima A-04 you prefer is a cheap class D amp. Average specs, has decent but not great reviews. Lots of people who own it say it has poor high distortion when played at over 70% volume. You can't expect miracles from the really cheap class D amps like the Aiyima A-04. The class AB Fosi Audio HD-A1 is much better spec wise including much lower THD and much better sound wise judging by the much better reviews from people online and on RUclips.
My Fosi Audio HD-A1 arrives tomorrow. My bookshelf speakers, RCA interconnects, reference power cable and reference mains block definitely don't lack detail. Sometimes you need to upgrade improve the parts of your system that's lacking to get the best out of a amp.
Most of the Amazon and Fosi site reviewers probably used the stock power lead that cost pennys supplied with the Fosi Audio HD-A1. Still got mostly great reviews nevertheless and considering the reasonable price though I always advise people to change stock lead to a good high quality power lead. It makes all the difference with the sound quality even with expensive Amps.
@@C--A I think I mentioned it was my experience. While the Fosi is well built, I tried three of the same amp, some variation in sound among them but all were more veiled compared to the Aiyima, at least to me. I guess I like detail and if there something to critique, well, that's also someone's prerogative.
Yes, the Fosi produces more current, has more power, may even sound beefier, but they were all veiled, comparatively speaking. If I had to live with the Fosi, I could but would pair it with more revealing sources.
@@nc3419 everyone's ears and opinion of what they thinks sound good is different. But the Fosi Audio HD-A1 is definitely much better specced than the Aiyima A-04, that's a fact.
Plus the majority of reviews online and this RUclips video and 2 Dudes Audio disagree with your opinion of the Fosi Audio HD-A1 being like a veil robbing details from the sound.
Anyway enjoy the music as that's what matters most 🎶
@@C--A Well, fair enough but the distortion is low until you reach higher volumes. Have you listened to an Aiyima? Has anyone here listened to one?
Comparing it to my Emotiva A300 which is also a class AB amp they do sound similar where the Fosi is a bit warmer or softer and the Emotiva A300 is more neutral and detailed. Either way its fine people should pick the amp with a sound signature they like. Classic rock, blues or jazz is pretty sexy on the Fosi. Can't find the Aiyima A-04 for sale on Amazon or Ebay.
Is this Fosi suitable for 4 Ohm Bass Shake speakers and how much will it then be able to generate power in Watts?
Yes its stable down to 4 ohms
@@iowaudioreviews -- Yeah, but it doesn't deliver enough power to "Bass Shake" anything unless your listening space is in a phone booth, well under 50WPC into 4 ohms at 1 percent THD+N. My 20 year old Infinity active sub has 4x the power.
Your can a much better-performing -- 4x the power at 8 ohms and far lower THD+N -- Class D power amp and an appropriately beefy SMPS for half the price of this thing. Class AB no longer makes sense in limited-budget applications, where a properly designed amp built around a modern monolithic chip -- e.g. TI's superb TPA3255 -- can deliver incredible price/performance.
Very nice review !
I've heard it mentioned that this amp generates a lot of physical buzz or hum from the transformer. Not through the speakers, just a buzz heard when you're in close proximity to the amp. Has anyone noticed that?
My black Fosi Audio HD-A1 AC220V-240V UK voltage version arrives in a couple of days. I have heard the gold coloured model produces more hum than the black coloured model.
Also they say the hum is only there when Amp is powered on and no music playing. Once you play music the hum disappears completely.
Im replacing the stock power lead with a very high quality high performance power lead that is meant to eliminate any electrical interference from the source and the mains.
I'll report back later if I have any hum from my Fosi Audio HD-A1. My Amp is going in a AV unit so I likely won't notice the hum if I do have it.
I did not experience this mine is dead quiet.
@@C--A did it make any difference?
I need something to power up my home subwoofers that has no power nor sound
Hello :) is it more musical than a Behringer A800 ?
Yes, obviously not as powerful as the A800 but at least for me it seems to have warmer sexier sound signature. I really enjoy listening to classic rock ,blues, jazz and some acoustic on this amp.
Thank you !
@@iowaudioreviews "sexier sound signature" ?
Sound signature ?
Does it mean that it's not literally high fidelity ?!
Will you do a review of the Dayton audio mk402x
I actually had a set of these before I started my channel. They seemed to be good for the money and I used them for a few weeks then sold them to a friend. I'll ask my buddy if I can barrow them for a review.
@@iowaudioreviews That would be great. Thanks
When I first got this, I loved it but, all of a sudden I started getting static out of my speakers. I’ve done a lot of tracking to find the source and so far, it’s come down to the amp. Anyone else getting static through theirs?
@Thick Bad bitch Have a little more confidence in yourself. Just because your a stripper doesn’t mean your stupid! I did do a bit more detective work and found out what it was. I don’t like to use powered speakers for my computer so this is my computer amp. After I got a new computer, that’s when the static started. After much more detective work, I found it is the computer’s power supply. I bought a new one from a reputable company and installed it and no more static. It’s a shame that I had to spend another $100 on a power supply for a new computer that I only had for 3 months. Static is not covered under warranty so.........$$$
Booty shaking & good sound!!
Please send me the link of your sound test video.
Thanks
He's sending his Fosi Audio HD-A1 to Audio Science Review to do in depth measurements and analysis. Google Audio Science Review bookmark the site and check regularly to see when Amir reviews it.
Audio Science Review don't have a RUclips channel. It's just a website where Amir tests speakers, amps, dacs etc. Lots of very clever forum members on it who are very knowledgeable regarding audio.
nice
As far as only one input goes, just get a "little bear" RCA. Splitter.
isn't it better to buy a car amplifier? those are cheaper, you will probably get more power for your money, they offer more options too like being bridgeable, hpf, lpf. I mean, $200 for what they say are 50W?? i am no giving away that money for that. there is this pioneer that for $65 gives you 60W rms at 4ohms and there are plenty of other options that will give you far more power and options than this thing for less money. we also have things like the Pioneer SX-10AE Home Audio Stereo Receiver that for less money gives you more power and options than this thing. just asking.
This amplifier isn't about power per dollar. If thats what your looking for, $200 will get you a nice used Crown, QSC or Behringer power amp. The Fosi HD-A1 was designed with sound quality and fidelity in mind, it will definitely sound better than anything you mentioned. Affordable car audio mostly consists of cheap class D amps that really don't have the power thay claim. The Fosi HD-A1 is 50w x 2 @8ohm and the Pioneer SX10AE is 45w x 2 @8ohm. The Pioneer has more options but I'd be willing to bet doesn't sound as good. A lot of this will depend on having good speakers and listening to a good audio source like CD or FLAC/WAV files. If all your music is just streaming or mp3 the SX10AE will be fine. Also watts don't work the way most people think. To go up 3db in volume which isn't much you have to double the power. So you really won't notice the difference between 100w and 125w, you would have to get up to 200w just to gain 3db. The problem is companies have been listing Max power on product for the last 30 years and people have gotten used to there usless high numbers thinking they need hundreds of whats when in reality 50w RMS or continuous is a good amount of power. Look at many vintage receivers from the 70s that are only 30 or 40w continuous power but could rock the whole house with a big set of speakers. One another note if you listen to mostly bass heavy music then you may want more power as lower frequencies take more power to push with clarity.
@@iowaudioreviews i am curious, why wouldn't the car amplifier sound as good as that amp? have you performed any testing? real testing. i am just wondering. wondering if paying all that money really get you all the magic people think are getting. i do not really need that much power, i just want good sound. when i look at those receivers from yamaha for example, they have so many inputs that i do not really need but are unable to play from usb nor do they have an equalizer plus the price is just insane on the basis of super special fidelity advertisement. i also only need stereo sound not 7.4.5.6.6.6...... speaker system. i know manufacturers usually pump the power really high and they now use peak power instead of the old PMPO.
using a toroidal transformer won't make it really sound any better. what lies after the transformer is what will make the difference. they could have used switching power supply too.
@@iowaudioreviews 100% accurate! The Crown XLS series and the Behringer A800 Class D reference amps are a worthy mention...I do like this Fosi Audio HD-A1 very much, I bet it is every bit as good as it looks inside... TY for the review....it was real nice!
@@Billy-rr7re - Most car amplifiers are engineered to just be loud and push bass so they typically don't have the best specs when it comes to fidelity, lower SNR and higher THD. There are good car amps like JL Audio but $$$. Real testing would come down to numbers and most car amps at $180 don't have very impressive numbers other than watts. Granted most car amps are Class D and this Fosi is Class AB. Generally people favor Class AB amps for power and musicality but Class D is getting much better these days. Far as testing I mention in the video I will be sending this amp off to AudioScienceReview for professional testing. Once hes done with it I'll link the results in the comments. Now far as hearing a difference if you just listen to the radio, mp3 files or streaming services you probably wouldn't notice much difference in sound quality as those are all lower quality sources. Now if your primary source of music is vinyl, CD, FLAC or WAV files and you have good speakers the difference should be more noticeable. Not to mention in either situation you would want to use a decent DAC to get the best of the amplifier. When it comes to cost $200 is affordable for a amp of this quality. You don't have to spend a ton of money probably about $350 to get a system that can make a well recorded album almost seem magical. I may do a video in the future about using a car amp in the home.
@@iowaudioreviews cool, and what is your opinion on car stereos? do they have a good sound?
Fosi hd-a1 vs Dayton apa150
I may have a APA150 in the future we'll see. I am familiar with it though. Comparing these two amps is apples to oranges when looking at who they were made for. The Fosi is basic affordable Hi-Fi and the Dayton is value with power/performance/versatility for an affordable price. After reading the APA150's test results from ASR it shows exactly that. I have sent the Fosi to ASR for testing so after the results are posted well at least see in numbers which is better. But my presumption is the Fosi will have better fidity but less power. The APA150 performed well enough to satisfy most people in its price range. Here's a link check out the review. Thanks for watching. www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-dayton-audio-apa-150-amp.6571/
On a side note two APA150 side by side in mono would be pretty cool BUT for the price a Crown XLS1002 or Behringer A800 would be better....idk.
De verdad que pesado...ábrelo de una vez!.La revisión podría haber durado 3 minutos...no mas!!.además se te escapa lo más relevante...lo siento no me gusta tu rewiev.
El potenciometro , - que es lo que me interesaba - , es alps 16 o alps 27???
In a world where there are cheaper and a TON Of high quality D class amps, why would you get this AB amp? Nostalgia? pfft.
for example? for 150$?
Are you being serious? Class D has come a long ways, but still can't hold a candle to a good A or AB amp. To each their own.
Most cheap Class D Amps deal with many problems, take some time for googling.
The 2 "budget" class D amps I'm aware of, avg cost is $500. XTZ, Hypex ???. More power, yes! Sonics? IDK??
introduction is too long!