DIY LM3886 (gainclone) Power Amplifier No. 2

This is the second LM3886 based amplifier I have built. It produces about 2x 42.5 W @ 8 ohms. The VU meters originate from a Sony TA-212 amplifier.
Michael van den Born - 2016
www.flickr.com...

[@srdjant0]

Love this design. Really lovely. I'm building a stereo LM3886 and I think there's no way mine could be as clean and wonderful, but you give me inspiration for my own project. Thank you!

[@skipperrussell2025]

Your gainclone sounds really good over the internet and through my gainclones. Mine is tri- amped.

[@NikiDorian]

Beautiful work!

[@adityamody8942]

Looks and sounds beautiful

[@Georges-MILLION]

Très belle réalisation !!! Bravo ! Georges

[@PA4MW]

Merci! :-)

[@BertKrus]

Amazing and beautiful 😍

[@PGHJR002]

Excellent sound quality!

[@PA4MW]

Thanks!

[@tremor8197]

Nice job uv meter is excellent

[@rogerwillams2814]

wow mind blowing sound !

[@quattro4468]

Sounds awesome. DIY all the way.

[@newENIO11]

Nice, eminence front!

[@porouri]

잘 만드셨네요.

[@kelvinham8576]

Hey, beautiful build, great layout, beautiful styling. Whats more, probably sounds as good or better than high end amps costing thousands.

[@saraki4311]

I like it!

[@evertonnerlancarvalho6216]

This music remember Grand Theft Auto San Andreas.

[@elio965]

Can I ask how do you connect the VU meters in the circuit ? Thanks, wonderful job (and music) !

[@alexmoldovan7249]

Awesome!!! Sounds great and looks the part! What is the VU Meter model? I would love to add the same model to my power amp

[@TheRsxer63]

Where did you get the VU meter kit?

[@inception-hifi]

OMG! Where did you find this VU meter?! In my childhood in 1979 we had a Sony TA-515 with a same VU meter! I'd like to order the same for my GC but I can't find it...

[@TheTycarroll]

I have the same issue, does anyone know where we could find VU meters like this for sale? Or is the only way to find and old amp and tear it down???

[@odejan2]

Exelent, i build one lm3886 but not beauty's like your's

[@wolidhassanbadol4045]

AC 27 0 27 sony trnsformer................run.............yes or no

[@diyhifi2632]

woow

[@carsandstuff711]

Gorgeous build. How is the Vu meter connected/ wired?

[@PA4MW]

Thank you! In this video I explain a bit more about the circuitry: kzbin.info/www/bejne/aWKop3hjistgqsk The circuit has been made on 'veroboard'.

[@adoniscmj3212]

Love your builds, where did you find the amp chassis? I am planning on doing something similar. I want to build a small component system. Amp & preamp.

[@NinoJoel]

I have seen this chassis on aliexpress.com some time ago. There is a link so a simular one since i cant find the one that was in the video right now. de.aliexpress.com/item/NEW-arrive-YJ-WA53-tube-amplifier-chassis-aluminum-amplifier-enclosure-amp-case-aluminium-chassis-vu-meter/32809690622.html?spm=a2g0x.10010108.1000014.20.350f4357ejAGcQ&traffic_analysisId=recommend_3035_null_null_null&scm=1007.13338.80878.000000000000000&pvid=a1fe9cb6-4449-4193-81ff-3982da239d5d&tpp=1

[@birdmedicaldevices]

Hello where can I get this VU meters ?

[@indigobaloon8091]

Such a big transformer and only 42.5 watts?

[@staLkerhu]

LM integrated circuits are a bit weak compared to how power hungry they are, but it pays out in sound quality.

[@diyhifi2632]

where did you buy the side panel aluminum?

[@PA4MW]

Unfortunately I am not allowed to post links, but when you hit Google with 'hifi2000' you will find the supplier.

[@dzezydzerk]

how is sound recorded? from speakers? awesome amp!

[@PA4MW]

Thanks! :-D It has been recorded via two shelve speakers (B&W DM302) and a microphone that I hooked up to my Canon EOS 650D DSLR.

[@zekafe65]

süpersin

[@rogerwillams2814]

i always believed the lm3886 was bad azz amp chip ha ha !

[@hekkenfeldt]

What is the music playing?

[@PA4MW]

The Who - Eminence Front :-)

[@BogdanWeiss]

Where did you source the analogue meters ? They're hard to get these days funny how "old stuff" comes around again.... I can highly recommend Rod Elliot's 200W mosfet I've heard it next to +$20K Krell monoblocks in a mastering studio.....The Krells went back to the dealer... Rod's mosfet was deemed more neutral by the engineers....sound.whsites.net/project101.htm

[@PA4MW]

Those meters originate from a Sony TA-212 amplifier that a friend wanted to throw away. There is nice 70's equipment around that is sometimes not repairable, but great for salvaging parts. You could try Ebay. Even brand new VU's are offered there. However, I personally prefer salvaged parts :-). That seems like a nice project! Very curious how it sounds. I have build a KSA-100 clone a few years back. I like this beast quite a lot, but man... thermal management is not easy when fully biassed into class A ;-). I still have to make a video about this amp, but there are some pictures on my Flickr page.

[@BogdanWeiss]

I thought the meters were a salvage job - though they match the amps power rating so you got lucky twice ;-) Rod's 200W Mosfet sounds amazingly clean open & dynamic. I had the pleasure of selling several units into a number of top recording facilities in Sydney - it's the hardcore mastering crowd who "get" that jamming amps into loudspeaker enclosures is not a good idea... it's a deceptively simple circuit with a great PCB layout - Rod used a custom made Faraday shielded transformer & an exemplary analogue PSU layout with fat Cu buss-bars & separate PSU for slow turn-on. I've listened to a lot of different gear over the years - Including the silly $$ stuff like AN Ongaku & it's as good as it gets. Thermally stable into reactive loads & good for 400W/channel into 4Ohms.. what mooar you want ? What's more important to me is how good it sounds at very low volumes... it's the Krell/Threshold sound minus the heat

[@fix-diy941]

สวยงามๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆๆมากครับ

[@theOneUser]

Hi, are these the same dimensions as here kzbin.info/www/bejne/bmaVcp-HjK5paa8 ? Or is the depth 280mm? Thanks P.s. very nice amp!!

[@user-jq6jl4fq7w]

Вы собираете усилители ? сколько стоит ваша работа?

[@PA4MW]

Я уже построил 12 звуковых усилителей. Скоро я буду добавлять новые видео.

[@user-jq6jl4fq7w]

Вы их делаете на продажу ? сколько стоит усилитель в сборе ?

[@user-zp7fn2is8z]

Подскажите, что за индикаторы уровня, где приобрести?

[@PA4MW]

@Александр Буров: Индикаторы взяты из усилителя Sony TA-212

[@PA4MW]

@Илья % Извините, просто энтузиаст DIY, а не коммерческий :-)

[@1959Berre]

What pre-amp?

[@PA4MW]

For this video in particular I connected an Accuphase E204 as pre-amp.

[@meme-sm8te]

what tranformer did you use ? voltage ? do the LM3886 get hot ?

[@PA4MW]

The transformer is an Amplimo 78015 (300VA, 2x 22VAC). 300VA is overkill, but I prefer the 'build like a tank' approach ;-). The LM3886 are at maximum 42 degrees C (measured with my Fluke 62 max) at ambient temperature. So that is more than acceptable. It also depends a little bit on your load, but considering that these measurements were conducted with a 4 ohms load, the LM3886 is kept cool nicely. Mostly when people experience an LM3886 to run really hot, there is a good chance that it is oscillating or they did not use (or apply a correct amount) of thermal paste. Always check the square wave response and for possible oscillations with a scope; better safe than sorry :-).

[@seven3pl]

Hi. Can you make one for sale? :)

[@PA4MW]

Sorry seven3pl, hobby only, not commercial :-)

[@staLkerhu]

@@PA4MW hello there! I will buy a similar amplifier + power supply kit without transformer from ebay. Could you please help me to choose the right transformer? Your description and the LM3886 data sheet PDF makes me confused. You said you used a 300VA 2x22V transformer and you get around 2x42,5W output power. The PDF document states things a bit differently, and even has some contradiction in it. The "Electrical Characteristics" table says with 8 ohm speakers you need 28V to reach 38W typical PO and 35V to reach 50W typical PO (THD+N=0,1% max) so things are already different. What makes this even more strange, there is a diagram in the middle of the document called "Output Power vs Supply Voltage" which shows how much voltage do you need for 4, 6, and 8 ohm speakers to reach the desired output power. The 8 ohms line shows you reach only 31W with 25V, 28V required for 41W (wich is pretty close to 38W mentioned by the Characteristics table), and then things gone stupid nonsense. It shows you can reach 64W with 35V... I know the table said "typical", but I think 14W difference is a bit too much. So here I am, trying to figure out what transformer should I get. I don't want more than 50W per channel, because it is the limit of my speakers. I planned to buy a 2x25V 300VA transformer, but if you get 42,5W from 22V then I assume 25V would provide WAY more than 50W. All in all I have absolutely no idea what is going on with the numbers. Please help me sir 🙁 Edit: I have a feeling you accidentally mixed up the 4 and 8 ohm lines, because on the 4 ohm line 22V connects with ~43W.

[@PA4MW]

@@staLkerhu That is great news, these kits are truly fun to build. Know that this LM3886 build is heavily overdimensioned, 300VA is certainly not needed. The voltages mentioned are VAC, so these have to be multiplied with sqrt(2). That results in a rail voltage of more or less 31VDC and I think that aligns pretty well. I have not mixed the lines up ;-). It is possible to push the LM3886 further but realise that already a 1W RMS signal is enough to make the neighbours mad. I think you are safe with any transformer between 2x18VAC and 2X25VAC > 100VA. For more power I would choose a different design.