plexi 50 watt clone with very strange issue - Non Tremolo making pi trem sounds ?...

[g1]

I'm still not clear on the cap position. You said it was C106. The two sides are in parallel. So you can't have AC on one side and not the other. Is it C105 instead? If so, which side?

[spinfresh]

yes and i have a beautiful sine wave...
sorry from iphone - this is on the last half filter cap before the preamp section ...
I am going to change some coupling caps from the preamp to the power amp and see what happens,
thoughts

[g1]

So C105A for the PI node then.
And that is not a "beautiful" sine wave . It is much more pointy at one end. Looks more like a ripple waveform. Slow down your time-base on the scope, it should be about 120Hz.

Edit: On the other hand, if it is ripple, it should also be on the caps closer to the rectifier. What is the frequency?

[spinfresh]

thank you everyone... I figured it out... THE CHOKE is bad, I just wired in a new one and bam works like new... that is a new one for me, i have never had a bad choke on an amp EVER...

THANKS for all the help.

Paul

[g1]

So I guess that scope picture would have been C105B then.
This is the unfortunate thing about ceriatone, no schematic, and even if we would have had a layout, no corresponding schematic.