Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: acheld on September 24, 2020, 03:44:55 pm
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I built an AB763 (DR) several years ago, and I love the sound but now need a physically smaller amp. And, as Doug states in the One Channel build, "whoever uses the Normal Channel anyway." In theory, I would have used it; in practice, I just didn't.
So, I'm going to re-use all the expensive bits and rebuild as a Hoffman One Channel AB763 with 6V6's.
While going over the schematics for the Two channel and the One, I see that C22 (both schematics) use a .01uf coupling cap for the Two channel, and a .001uf for the One channel design. Why would this be so? On the Two channel schematic, there is the notation "Suggested value." The original Fender design uses a .001uf cap in this position (I'm not sayin' this is better . . .).
Just curious. My original amp used the .01uf coupling cap, and it sounds great.
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...My original amp used the .01uf coupling cap, and it sounds great.
So why would you use anything else? :wink:
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Well, I won't do unless there is a good reason not to.
I was curious why Doug made that design decision.
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0.001 seems small for "most" coupling-cap applications.
The input to a long-tail is one place where it is not too small.
0.01 or 0.001, about the same cost either way.
This is NOT important.
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OK, thanks.
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The AA864 Bassman even uses a 500pF in that position.