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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I will try without compensation caps ...my curiosity
Is any of these Peeceebe working well (no oscillation)without compensation?
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.
Good news!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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This amplifier didn't love compensations caps at all.
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.
Mr.Mile that's it for you.
Dummy load=6R//470nf.
All these without any compensation.
Very good, thank you.
Regards
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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Saan we have very good news!
This amplifier didn't love compensations caps at all.
All these test without any compensation.
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.Thimios, good work, did you try same test with speaker connected no dummy load?
If yes, I'm going to remove comp caps immediately
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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