Class D amplifier basics for DIY audience designers part 1-6
HTML-код
- Опубликовано: 30 июл 2024
- tcrastrs.com In this tutorial, we will cover the most critical Class D design aspects to be able to distinguish between good class D amplifier designs and bad ones. Based on this knowledge you will be able to understand why one eBay class D amplifier model sounds great and others do not.
This tutorial is based on the largest chip manufacturer companies' publicly available applications notes and reference design documents. Most of the good eBay Class D amplifier boards are simplified large manufacturers' reference designs. Special Thank You to International Rectifier/Infineon and Texas Instruments engineers for a well-structured and most completed set of documents. For those listeners, who have an Electronic Engineering background and willingness to study more I added links to source documents at the end of this tutorial. 
Наука
Fantastic breakdown of the amplification technology. Very much appreciate the effort put into this.
Excellent video ! Thanks for the insight into switching Audio amplifiers . I always wanted to build them .
video is really great! All you want to know perfectly put into a single video 🤩 Thx a lot for this, will be my reference forever!
Inspiring comment. Thanks.
Thank you for the very well done explanations.
Thanks for taking the time to pass on your knowledge. I learnt a lot.
Glad to hear that
Thank you, this was truly informative.
Awesome.. please make more video series like this about electronic
Very pleasing and enlightening.
Thank you for providing this tutorial!
Glad it was helpful!
i'm very thankful for this video
Glad that you find it useful. I makes inspiration to create another videos:)
Sufficiently professional as well as quite informative in delivering lectures on the mentioned subjects. However, thorough review of current circuits boards could be considered for average enthusiastic audiences.
Great video, if you’re academically inclined. If you are not, please persevere - there are a lot of practical real world lessons to be gleaned as well. My ear is very well tuned to different foreign accents, but if yours is not, you may need to watch the video more than once, which is an exercise well worth it in any case. I learned a boatload anyway, so big thanks for putting this rigorous but concise piece of research out there.
Just turn on subtitles.
Excellent!
Glad you liked it!
3rd gen class-d don't use PWM. They're self-oscillated with varying switching frequency. 4th gen class-d, such as the new Purifi, don't even use dead-time. They're based on impedance source inventers, which utilize the shoot-through state to control the voltage, similar to a boost converter. Lastly, class-d are not digital audio amplifiers. They are switching type amps.
May be, but I did not had a chance to look at those in practice. We also should consider human hearing resolution. At some point better electrically measured device will not sound better to listener when we exceeding human hearing limits. This is like paying for 8k TV set and watching HD movies. I think with amps we are at the end of the game and quality fight should move to speakers. This is the right battle field for next gen audio. We still using 100 years old technology there.
@@guntarssmits2104 For my ears ice (irs based?) sounds almost similar to an ab class amplifier, but with a significantly worse highs than ncore or purifi UcDs. That’s audible despite of 0.00...% (when original modules are compared face to face)
@@sc0or I made a blind test experiment with the owner of 2 Hypex monoblock owner for a price above 1kEur with Icepower 1200AS2 and he was not able to distinguish between both when was not seeing which amplifier was playing. There is some community perception mainly due to the price difference of equal power projects. Amplifiers in our days are so good that for further sound improvement, we should go for active systems.
@@guntarssmits2104 I would checkout their GCOM (or how do they call it) modulator, but unfortunately cannot find any architecture schematic on the Internet. It's incorporated into their IC. However it would be interesting to check out D/S order (is it a D/S at all?), or coefficients, etc. I personally hear it has a pretty pleasant sound (better than tpa) but highs are not ideal
thank you sir!
As an ece student this video is very helpful for me
Glad to hear that, Digital marketing specialists said that nobody will watch it. I fact, this is my best seller fro audience feedback and retention.
Thanks, now i will watch all 6 Liked and subscribed :P
Respect, this is not an entertainment video at all. Glad that your like it.
I have been searching online for quiet a number of days now to find a complete guild to building a class D audio amplifier but all my efforts have seem to not any good result. seems like not many people have really involved in the design and construction of this amplifier type. Thank you for these Tutorial. If you or anyone here can share the practical implementation of the amplifier, it will go a long way for me.
There are practical implementation videos on my channel ruclips.net/channel/UC2yDSO46soRXRvQyhOfKr9Q
Really like your videos, would love if you can make an amp inspired by Rowland model 125 with some balanced and rca specially treated inputs based on irauda7s or ICEpower 125asx2. That would be great!
Hi,
Rowland model 125 looks great and specs are outstanding. A bit pricy, but good unit all around
I have good news for you. We are designing a superior balanced input board based on the latest Texas Instruments chipset. To fully benefit from balanced input, you need carefully selected components in the input stage with tolerance better than 1%. It is almost impossible without chip level integration. Texas Instruments developed such chipset giving possibility to design small footprint balanced input board to locate it close to signal connector. For perfection, you need dual voltage power supply like +/-12v. The main challenge will be finding a good power supply with a separated amp power line and preamp voltage. It should be also tested for pop up noise cancelation. It may happen that you need special delay circuits to avoid it. Once we will test full design, I will publish video and reference design guidance.
From another hand, unless you do not have a signal path longer than 6 m it does not make an impact on your sound performance. Balanced circuits are made for professional application where you need to run signal for distances from 10- 300m for mc level. Amp signal would be transmitted up to 1000 with well-balanced inputs and correctly designed balanced source.
@@guntarssmits2104 Sounds great, I'll be waiting for the video!
Great job!!
Inspiring comment :)
I’d be happy to watch yet more episode about “0. Modulator architectures” pls
PS Cause a triangle wave comparison modulators these days are outdated
At 12:13 you duplicated the TO-220 gate on waveforms. Can you provide the gate off waveforms for comparison?
Unfortunately, prototypes are archived and it is not possible anymore. I took a note of your interest. Maybe we can measure it in some future projects.
hi excellent,if i want to do diy class d amp,what parts do i need i would like 3 channel 200 watts each with full bandwidth texas instrument vs infineon thank you
Question is a bit to generic. Your biggest challenge is not an amplifier part but good power supply. There are plenty of amplifier boards in eBay doing good job but practically there is not good switching mode power supply with decent stabilization and clean DC in output to feed amplifiers.
hello, good day, very good, your tutorial, you have the document of that video that I can translate into Spanish, it is very interesting, if you have a pdf, I appreciate it, greetings from Colombia
Hi, It was a long time ago when I made this video. There was no PDF made for it. The only way Is to copy screens and download the transcript. I think there is no restrictions on that. In RUclips there is instruction how to download the transcript.
I been looking at ice amps on parts express and I'm interested in them but I don't know if I need a pre amp
In general meaning, you need a Preamp/DAC or streamer or any other device working as a source for the amplifier board with output voltage in the range of 2V-4V RMS and low output impedance of 150 Ohms. You do not need a special small board in addition to the amplifier board unless you are not going for a bridged solution or any other modifications. I also recommend looking at the Soundimport Icepower lineup which is broader than Parts Express.
@guntarssmits2104 thank you I been watching your videos and they are very informative. I was wondering if you have a website for your product
@@BostonMike68 www.tcrastrs.com
I have heard that TPA-3255 is one of the better class D amplifiers. Check it out.
Industry continuously developing TPA 3255 is good chip. But the last tests is blind listening test and you should be able to make 80% correct answers for the better amp.
Prices
Class-d biggest mistake s applying LPF separately to each bridge-leg. You should only apply LPF to the full-bridge differential output without any connection of the LPF to the supply ground!
Why? Because when modulating two legs using a balanced source signal, the effective switching frequency at the differential Vab output will be twice the physical switching frequency of each leg! This translates to lower THD at the load.
Also, the switching frequency should be at least 650kHz per leg, for the amp to be fully capable of handling the full audio bandwidth. Otherwise, the amp is only good for subwoofers...
You also must make sure the audio signal at the input does not exceed the level of the carrier signal, to ensure only linear range modulation.
Hi Barbie, can you share your knowledge on D class amplifier with me? sam_desd@yahoo.com