Dual TDA 7293 Amplifier.

[@ianfisher6561]

I am always delighted when the "closed" channel springs to life again.

[@MichaelBeeny]

I used to be indecisive, but now I'm not so sure.

[@new-kids-on-the-block]

​@@MichaelBeenywe realy like the video just take your time ❤

[@danskebassister22]

Ohhh, SO GOOOOOD to see you back, dear Michael. I truely missed your precense here - and I appreciate your practical approach with affordable DIY hifi, which I guess is a common hobby for most subscribers here. I hope you will continue here as long as you feel fresh and enthusiastic. Life is supposed to be good and comfortable even though the process of learning very often comes from being tested on life. Statistics have proofed that we will all die from utter life eventually. So respecting death we can consider life as a free fall off a huge skyscraber: We have two possibilities; we can either scream in agony and despair all the way down - or we enjoy the trip, look in through the windows on each floor and remember to say "hi - enjoy your day" and share smiles and good energies on our way. I just love the fact that you decided to return and share more wisdom from your own experience. A HUGE respect and loads of love is due. Thanks for being here - please return every day you possibly can. Your efforts are HIGHLY appreciated form my side. Best regards from Peter Rahbek in Denmark.

[@MichaelBeeny]

NOTE THE INPUT CONNECTION IN THE VIDEO ARE REVERSED! SORRY!!

[@ryanchappell5962]

I’m learning a lot about electronics from this kind of presentation

[@TRONMAGNUM2099]

Excellent video. So happy you are able to still make videos from time to time. I have learned so much from your videos.

[@TrevorsBench]

Great to see you back Michael

[@MichaelBeeny]

Thank you, Trevor, much appreciated.

[@remarpc]

Thank you for getting back in action to publish this review. 156W clean output @4 ohms, coming from a dual 40V supply is great!

[@MichaelBeeny]

Not many amplifiers really impress me but this one really sounds great.

[@dannyruth9925]

I’m glad you’re back! Can’t wait to see the build video(s). The way you explain things makes it really easy to follow your builds.

[@dannyruth9925]

Glad you’re back. I can’t wait to see the build video(s). The logical way you explain things makes it easy to follow your projects.

[@ronschauer839]

GREAT to see you "back on the air" again! The dual chip design is the way to go in my opinion, and as you know there are tripled versions (but none of them that I know of have the op amp in the feedback loop). All the better to shed the component heat. As for the capacitor near the heat sink, that is very easily remedied. Again, welcome back!!!.

[@mauriciojv7901]

Hi Mike, So gratifying to see you (not) back with us and looking so good. Great content e passion in sharing with us. A huge salute from Brasil.

[@KP-nd3bx]

Looking forward to hearing more from this project. Greetings from 🇩🇰

[@harshsharma-tj2lg]

Dear friend It was great to see you back in good health and spirits. Keep it up. May God bless you.

[@TT-it9gg]

Good to hear from you again. Best wishes~

[@yourchildrensghost9736]

Nice to see you doing well, Michael.

[@TerryMcKenna]

Inspirational and much better than any program on the TV. I'm looking forward to the next video, thanks. Stay safe.

[@MichaelBeeny]

Thank you, Terry, for your very kind words, I really appreciate them.

[@TerryMcKenna]

@@MichaelBeeny It might be better if the board came without the 7293's soldered then we could lay them flat like LINN did originally this way cap location isn't an issue. I'll likely build mine this way.

[@KP-nd3bx]

Nice to have you back. 🇩🇰

[@daveg8htfadlibaudio250]

Nice to see you back Michael. 😀

[@johnh544]

Hafa Adai from the island of Guam. I enjoy your videos... Your observations and style of delivery are great. Thank you for your efforts in putting more content on your channel when you can. Take care!

[@MichaelBeeny]

Thanks John, most appreciated.

[@raceingdemon6464]

Great Video Michael And Looks Like a Fab Project For Sure Looking forward to part 2 Glad Your Still Strugling On Just Like Me Regards mike.

[@Alex-dv1eu]

Очень рад вашим открытиям и тестированию! Прекрасно объясняете и делитесь своим опытом и знаниями! Надеюсь увидеть и услышать его в готовом виде!👍🤝

[@nakfan]

Thank you so much for sharing this in spite of your health issues...Very appreciated 👍 I am looking forward to the next video in this series. Take care. All the best, Per (DK)

[@TRONMAGNUM2099]

Looking forward to part 2. Nice amplifier. Tons of power to drive even larger speakers.

[@garygranato9164]

hope your keeping well, thank you for the video

[@franklekwan5860]

Hi Michael, it nice to see you! And what a nice video and I am looking forward for the Part 2. Also, it will be nice if you can trace the schematics and see what the op-amp is actually doing. 💪

[@MichaelBeeny]

I'm also looking forward to seeing part 2. I've got to make it now!!

[@englishrupe01]

Lovely to see you back, Michael. One thing i would note is that those solder connections on the 7293's are pretty poor and could do with touching up, as several of those have not soldered through the board and would have less heat produced and better efficiency with a through-board connection. Probably just a result of that awful lead-free solder they have to use. Many thanks for the new video.

[@MichaelBeeny]

I thought the soldering was reasonably good. It always looks worse on camera due to close ups and bright lighting.

[@DavidBrown-fi8vr]

The sinewave test reminded me of setting up AB's for stress testing, set the level to max Vce and 4 ohms... you thought that heatsink was big enough... just as well audio doesn't have that impact on the entire chain, diodes get hot too and very ignored. Always a good idea to have a small fan and a wall psu handy for those tests... bacon & eggs anyone :) Nice to meet you, thanks for your time!

[@billkalina3089]

Hi Mike! I was anxious to see your progress on this. Seems it lives up to expectations. Nicest square waves I've seen! I may have to invest in this, although I'm afraid it may render all of my other gear redundant! Looking FWD to the finished product. I wonder if a kit is available.

[@MichaelBeeny]

Not seen any kits yet Bill. I'm listening to it right now.

[@keybutnolock]

I hope you're keeping warm ; ) thanks for sharing.

[@VirusForPrez]

Hope your health is getting better Michael -Greetings from Canada my friend !

[@MichaelBeeny]

Thank you for your kind thoughts, but sadly you don't get better from heart disease.

[@carlosah2598]

Good job Mr Beeny as always...

[@mariojsworld]

Nicely presented.

[@PaulMorganRyder]

This was just what I was looking for. I cant wait for the next video. My project is with one 40V SM power.

[@MichaelBeeny]

Don't forget this amplifier needs at plus AND minus supply at a maximum of 40 volts.

[@PaulMorganRyder]

@@MichaelBeeny I know that, and going one +- 40v that I have one hand.

[@MichaelBeeny]

@@PaulMorganRyder Just checking Paul. Not everyone understands these things.

[@PaulMorganRyder]

@@MichaelBeeny that's true. I have made my self many amplifier over the years from class A to D. And as long as you have a really stable and fast power supply then your good. But I find that l now leaning towards Switch mode power with analogue amplifier. Of course we need a really low noise power.

[@MichaelBeeny]

@@PaulMorganRyder I don't have any issues with SMPS, in fact, as you can see, I used 2 of them in my initial tests on this amplifier. My own experience is they can be unreliable.

[@bertbrecht7540]

You are an excellent teacher and I just subscribed. Thanks for your effort in bringing this to me. Are these chips real in your opinion? They seem to still work well.

[@MichaelBeeny]

Yes I'm sure they are. Fakes don't give such good results.

[@marknielsen8977]

It's a Claytons Channel....The channel you're having when you're not really having a channel.....Keep up the excellent work.

[@MichaelBeeny]

lol. I'm not sure I understand your comments, but it is early in the morning. Maybe after I have had my cuppa T.

[@marknielsen8977]

@@MichaelBeeny Claytons is a non alcoholic Scotch and back in the late 70's while launching it their slogan was / is - "Claytons, the dink you're having when you're not have a drink"

[@danskebassister22]

Michael, please come back. Lets have an encore. We miss you MUCH!!!!!! Wishing you the very best.

[@MichaelBeeny]

I'm working (very slowly) on a follow up of the completed amplifier. I only wish everyone could hear it. It really sounds good; it's going to be my main amplifier. I hope to show everyone ASAP.

[@carlfranz6805]

Sad you can't find this board anymore.

[@carlosah2598]

I wonder if the class A amplifiers like "1969" as well Jean Iraga desings are so wonderful compared with a 7293 or AB mosfet types...

[@MichaelBeeny]

Personally Carlos, I cannot see the point of class A. The only real difference is bias (apart from wasting tons of power in heat) Older amplifiers had the so-called transistor sound, largely caused by cross over distortion. These days crossover distortion is a thing of the past. You simply make sure the bias is set so no trace of crossover artifacts exists. Together with negative feedback the signal is as clean as class A without all the heat. What's not to like. Try the double 7293, it really sounds good, read what some of my viewers have also said about it. I now use it every day, as my main amplifier.

[@ryanchappell5962]

I would love to see your complete project.

[@MichaelBeeny]

I'm working on it right now Ryan.

[@michaellundsrensen2292]

Thank you, Michael. Looks like a good amplifier, will look forward to the complete build! Haven't you got a problem with you're fan? Sounds like the propella hits something!

[@MichaelBeeny]

No Michael, it just suffers from being a piece of junk. lol. It does the job, just about.

[@stevesmyth4982]

Hello Mike, that cap near the device would be better placed on the underside of the board and horizontally mounted. Eight of the amplifiers (four each channel) mounted on a cold plate would comfortably drive my old Quads and consume a lot less power than the class A amplifiers currently in use.

[@MichaelBeeny]

Don't talk about it Steve, do it lol

[@andymouse]

Great content !....cheers.

[@el_arte]

Excellent discovery, Michael! Thank you! Also, I know your channel is closed and you absolutely do not want to make another video, but…is there a better way to live than to stay curious and engage in things we are passionate about? I have an interesting topic for you (eheh,I am projecting, aren’t I?): Headphones amplifiers and/or output buffers aimed at enabling headphones jacks for a broad range of impedances/efficiencies.

[@ronschauer839]

I would second this. I listen to my stereo system using headphones probably 90% of the time.

[@el_arte]

@@ronschauer839 The origin story of that behavior for me is COVID-19. I have a nice set of speakers and I love to listen to those, but when when COVID happened and I started working from home, I soon found out me and my family don't necessarily have the same preferences and me using my speakers all day long turned out to be a major source of conflict. Eheh. So, I still listen to my speakers in the evening, but during the day, it's headphones, to preserve the peace. That being said, the topic I alluded to above is just as much about adding output buffers to allow equipment that was not designed for headphones to work well with headphones (pre-amps mostly, and valve gear with high output impedance), as it is about amplifiers for headphones. Every time I bring that topic up, my EE friends scoff and say "just buy a headphones amp, they are cheap". And they are right for the most part, except that headphones come in all over the input impedance/efficiency matrix, and some need more voltage, others need more current and all want the a damping factor > 10. Plus, I also think it's cool to give vintage gear the opportunity of driving modern headphones at their best, beyond the traditional series resistor or L-pad. But I ramble...

[@MichaelBeeny]

Watch this space, I hope an interesting and important video on WHY use a buffer!! I'm working on it. At the mercy of China post right now. You better ask Ron Schauer, he's the headphone man and a good friend to me!

[@MichaelBeeny]

@@ronschauer839 In my long-lost youth, I had a pair of 600 ohm AKG K60s. Slightly light on bass but a clean open sound. For about 2 weeks I also had a pair of Koss Pro44A or some, similar number. These were so heavy and dreadful, I hated them.

[@el_arte]

@@MichaelBeeny I could finance part of that project, Michael…I don’t mean for you to incur undue expenses. I can Paypal you.

[@jameswarren1831]

It's good to see you!

[@MichaelBeeny]

Thank you, James, but was the video any good?

[@jameswarren1831]

@@MichaelBeeny I was so happy to see that you're doing well I wasn't paying much attention to the info:) I went back to the tests to see the specs, and really got a kick out of how happy you were with the performance. So yes, it was great and I look forward to the next one.

[@ford1546]

another thing is that this type of amplifier gets a little too hot a little too quickly. Would like to see how hot the l12.2 amlifier card gets and how quickly it gets hot!??

[@MichaelBeeny]

If it's getting too hot quicky it sounds like the heatsink is too small. This combo makes a very powerful amplifier. The heatsinks from Ali etc are ALWAYS too small. This circuit that uses 2 in parallel dose use double the QI simply because it is after all 2 amplifiers.

[@ford1546]

@@MichaelBeeny Thanks for the explanation

[@beamer.electronics]

Superb 🙌

[@oguzaydin7482]

Nice to watch such great review. I have two questions, is it possible to compare the sound quality of this amp with TPA3255 amps? If we use LLC SMPS instead of transformer, does it effect the sound quality? Thank you for your review.

[@MichaelBeeny]

I don't really rate any class D amplifiers. The 3255 can be quite good but a great variation in performance between different makes. Some really very poor others fair, but they can be very low cost. Personally, I would always use a transformer type power supply. They are so simple and can be fixed should you have a fault. I find many SMPS very unreliable and often impossible to fix. Sound wise, no real difference.

[@max79444]

First class yet again !

[@MichaelBeeny]

Thank you, Max, most appreciated. More to follow ASAP.

[@max79444]

How much current from the power supply was the TDA7293 drawing at max power output?.. intend to build an amp using these boards. I've sourced a case with a massive toroid inside.

[@MichaelBeeny]

@@max79444 Sorry Max, as silly is it sounds, I forgot to measure it. At the time I was using my bench power supply's. I will note it down next time the amps on the bench and report back. At present the amplifier is in my listening room.

[@DavidBrown-fi8vr]

@@max79444 If massive means 300+ VA... it's irrelevant, invest in some quality caps for the PSU, that'll pay off unless you go crazy over the specs, you'll be paying them off instead

[@matt4days]

Great your back :)

[@nikolatesla4030]

Hi, can you please make an measurement with +-36V? I have them in the drawer....

[@MichaelBeeny]

The amplifiers are at present set up for listening, you can expect about 20% less power on 36 volts. It will still give excellent results.

[@nikolatesla4030]

@@MichaelBeeny Thanks. A question: You said that you contacted the supplier before purchase. You probably told him about your channel. I know that you are paying the things from your own pension and you are completely honest in your reviews (that`s why we watch them) but do you think that made him try harder for you? (better components, you said it was already welded which you didn't expect....). I'm interested in your opinion, I'm not provoking.

[@MichaelBeeny]

@@nikolatesla4030 I very much doubt it. They cannot receive KZbin in China, plus I always use another name and e mail address. The photos look exactly the same as the received units. I think I just miss read the advertisement, it's always an error to make orders from my bed at 1am in the morning. lol Don't worry, all is good.

[@ford1546]

I have tried a card with 2 pcs. TDA7293 in bridging and it didn't like 4 ohms! 1 ic. is recommended to have 29v 4 ohms. 30x4=120w take the efficiency to class-ab and you won't get 100 watts out of it. 1xTDA7293 you should preferably not use 4 ohm speakers

[@MichaelBeeny]

Maybe you had fake chips. Lots about. You have seen the results I found. Bridge mode, I would not recommend at all, even less so into 4 ohms, which is really 2 ohms per module. Amplifiers in parallel (as used here) makes much more sense and very happy into 4 ohms. With a good heatsink of course.

[@ford1546]

@@MichaelBeeny Thanks for the explanation.

[@danskebassister22]

Dear Michael. Thanks for your excellent videos here. I have several transformers, power supplies, cabinets, terminals etc "in stock". And now I want gto build an amp for my son. So, can I ask you - with regards to stability, value for money an, most importantly, sound quality (ie timbre, coherence, dynamics, details, resolution etc...; Which amplifier do you prefer. The TDA 7293 or the L12-2. Please give me a serious bid. Thanks Michael, from Peter in Denmark.

[@MichaelBeeny]

Peter, you do ask me difficult questions!! I've been using the L12/2 for about 5 years now and tested many others. I've always gone back to the L12. Class D no comparison. As you know I've tested a few amps of late using the 7293. Each one, so far gets better. The latest 2 chip Linn variation really does sound good. I am in the process of building a complete 7293 amplifier, I will be making a video of it as it happens. In all honesty you would probably be very happy with either. They do sound slightly different; the latter is possibly very slightly warmer but without losing detail. I really like it. Hope this helps a little, let me know what you decide.

[@danskebassister22]

@@MichaelBeeny Thanks, dear Michael. Your response is highly appreciated and I look forward to hearing more from you asap. I truly enjoy your efforts. You pave the way for me and many others. A biiiig THANK YOU is due! Deeperst respect, maestro. P

[@danskebassister22]

@@MichaelBeeny Thanks Michael. I worked for more than 25 years as a full-time hifi-revewer. Plus I have a technical background into both electronics, elektroacoustics and psychoacoustics - and, errr, psycho terapy . Wat a nasty combination. Anyway, combined experience tells me that; whenever you hear an amp with good resolution reproduce musik in a slighly warmer way, its somehow related to technical stability, I cant wait to hear more from you. THANK YOU for being that friendly, clever, relaxed and competent enthusiast who involve the next generation and pave the way for more and better music among those many who would never invest in a ticket to the opera or concerthouse.

[@MichaelBeeny]

@@danskebassister22 Thank you for your kind words, most appreciated.

[@georgebliss964]

I expect the paralleled I/C's should be good with 2 ohm loads, and how many watts can we expect then?

[@MichaelBeeny]

To be honest George I would never use 2 ohms with any amplifier. A 2 ohm speaker is not 2 ohms at all frequencies, it could well rise to 3 or more but more importantly, could drop to 1 ohm or even less. The amplifier would see a near short and could be in protect and possibly even shut down. Not really a good idea. Into such low impedance, if you really must, a 3-chip version is available. On paper it could offer 300 ish watts. Heat would be an issue. You do it against my advice unless you like smoke and fire!!

[@DavidBrown-fi8vr]

@@MichaelBeeny Indeed, the data sheet shows anything above +/- 30V and 2 ohms for the modular layout is the **forbidden area**...the days of SOA calcs and reactive loads lol

[@phoenix11994466]

Thanks, Michael, I can't wait to see the complete project so I can finally stop agonizing over dam Class D amps, which to my ears, always displayed an annoying GLARE which can be very distracting.

[@MichaelBeeny]

I must admit that I am never really happy with class D. Because of the output filters, they do sound different on different speakers. Much more than a class AB.

[@stevenbliss989]

Not so good soldering, the solder has NOT flowed through to the other side as it MUST to be a good joint!

[@peymandanaei5562]

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