Project 78: LTC6090 Op-amp and 2SC5200N in a Quasi-complementary Topology Audio Power Amp Project.

[@Maxim_Startsev]

Thank you for your work. Complementary transistors have different structures and cannot be completely mirrored. This scheme allows you to get rid of unnecessary nonlinearity and use the most similar transistors from the same production sequence. I don't have enough sound evaluation to figure out which amplifier to choose for assembly, I like the character of the old NAIM devices.

[@buildaudioamps]

Thank you. You are absolutely correct about your comment. I have mentioned how to adjust the crossover distortion issue in Project 58. I hope this will help you in your future projects.

[@OMarkica]

Nice project. Why did you extend the ground trace?

[@buildaudioamps]

Are you referring to the ground trace in parallel with the output of U1?

[@OMarkica]

​@@buildaudioampsYes, and also under C4 and R10

[@buildaudioamps]

The PCB is a single-sided layout, so a ground plane is not applicable for this project. However, ground traces are used to shield signal traces, especially when they run in parallel. This method can help minimize interference or noise and improve the overall performance of the prototype. Thanks for asking.

[@OMarkica]

@@buildaudioamps I understand now, thanks for answering

[@micheledestefano]

Quali pad hai utilizzato per la dissipazione dei bjt?

[@buildaudioamps]

Aluminum oxide pads, Aavid 4180. High thermal resistivity, good thermal conductivity, and stability at high temperatures. I've been using them since earlier projects. Thanks for asking.

[@micheledestefano]

@@buildaudioamps Grazie👍

[@HolgerBarske]

Thank you for all of your hard work, much appreciated. But: Why is your website gone?

[@buildaudioamps]

Where is your current location?

[@2pist]

I like the simplicity of it. Were your measurments done with the +- 50v p.s.?

[@buildaudioamps]

Yes at ±50VDC. Thanks.

[@OoGICU812]

What is D9 for? Doesn’t it take away half of the output wave? (forgive me, I can’t read very well)

[@buildaudioamps]

Diodes D9 and D8 are protection diodes against the back EMF generated by the speakers or inductive loads. When speakers move, they generate a back EMF-a voltage that opposes the original signal. This can potentially damage the power output transistors or cause distortion in the audio signal. If the back EMF exceeds the safe operating voltage of the power output transistors, it can lead to failure or damage. These diodes help to absorb and dissipate the back EMF, ensuring the amplifier operates properly and delivers clean audio signals to the speakers. I prefer to include them in most of my projects. Thank you for asking.

[@Al-bd8hm]

Thanks for the video. Excellent job. Where to buy trusted parts?

[@buildaudioamps]

From authorized distributors, this ensures you get genuine parts. Thanks.

[@troybrown9817]

Website looks fine to me. Good job!

[@buildaudioamps]

Thanks.