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Hoffman Amps Forum image Author Topic: Funky feedback tie to screens on Sunn Sceptre  (Read 2002 times)

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Offline Cups

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Funky feedback tie to screens on Sunn Sceptre
« on: January 06, 2013, 10:18:10 am »
Hello
My adventures with this Sceptre continues.
I was about to put some resistors on the screens and noticed that the screens are tied to the feedback network via a 390pf cap. Never heard of this. I attached a schematic:
http://www.webphix.com/schematic%20heaven/www.schematicheaven.com/newamps/sunn_sceptre.pdf

I'm debating cutting it. Probably just rolls off some highs in the power amp? I suppose I can work the resistors and the cap without cutting anything.
Suggestions?
And thanks again
Patrick

Offline sluckey

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Re: Funky feedback tie to screens on Sunn Sceptre
« Reply #1 on: January 06, 2013, 10:57:59 am »
Yep, even the original Dynaco amp had that 390pF cap. I've wondered about that cap too, but just left it alone. Figured it was just part of the magic. :wink:
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

 


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