I used to do such a test in all my amplifiers ,look at.http://www.diyaudio.com/forums/solid-state/236522-sx-amp-nx-amp-109.html
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Yes.
Mine, and if I remember correctly, nicosokey's. The layout may have played some role here.
If your board works without them then it's another good news. 🙂
Thimios, the power leads look quite long. If possible use 10uf or 100uf instead of 1uf for rail decoupling near the MOSFETs. Electrolytics will be okay. Also, as the VAS trannies share a common heatsink, try to short the heatsink to ground with a wire.
If oscillation occurs wihout the comp caps then then here are some fixes for it, increase the gate stoppers to 330ohms and install a 330pf cap to the gate and source pins of the N MOSFET. If oscillation still occurs then increase the comp caps to 47pf.
If oscillation occurs wihout the comp caps then then here are some fixes for it, increase the gate stoppers to 330ohms and install a 330pf cap to the gate and source pins of the N MOSFET. If oscillation still occurs then increase the comp caps to 47pf.
Ok i will try all this but keep in mind that i have used 47pf compensation caps. in last test.
The first test was without VAS common heat sink,compensation caps was 33pf in this case
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Peeceebee
Saan we have very good news!
This amplifier didn't love compensations caps at all.😱
All these test without any compensation.
Saan we have very good news!
This amplifier didn't love compensations caps at all.😱
All these test without any compensation.
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Peeceebee
Mr.Mile that's it for you.🙂
Dummy load=6R//470nf.
All these without any compensation.
Mr.Mile that's it for you.🙂
Dummy load=6R//470nf.
All these without any compensation.
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Big thanks thimios. Big hugs from me. You don't know what you have gifted the PeeCeeBee thread.
Honestly, I am a bit surprised. 🙂
I wonder, how come the plots are better without all the coveted Compensation capacitors?!
Well, Who cares.
Thank you very much again for your hard work. I am very much grateful and indebted to you.
Wow Thimios, that looks awesome. It confirms what our ears have been telling us all along. This is an amazing little amplifier.
Big thanks thimios. Big hugs from me. You don't know what you have gifted the PeeCeeBee thread.
Honestly, I am a bit surprised. 🙂
I wonder, how come the plots are better without all the coveted Compensation capacitors?!
Well, Who cares.
Thank you very much again for your hard work. I am very much grateful and indebted to you.
I'm glad as i help other guys building this amplifier.
Shaan, you offer to us a really good amplifier .An amplifier without extreme parts ,simple,cheep,easy.
Congratulations.
Best Regards.
Thimios.
edit- The circuit design credit goes to Gabor and Andrej. I just shared my board layout of it.
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Seems my choice of 2K2/100R over 1K/47R is justified. No additional compensation necessary to successfully build a stable and working PeeCeeBee.
Thimios, good work, did you try same test with speaker connected no dummy load?
If yes, I'm going to remove comp caps immediately 🙂
No, all this test is on a dummy load.
I will test it on a real speaker if request.
Isn't safe leaving this uncompensated without test this with a scope!
If you haven't a scope pay attention ,put your finger on zobel resistor this must be cold.
Out transistors must be cold also ,when amplifier isn't playing.
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