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previous: ADM I've noticed that some Ampeg's have... -- 4/19/2000 5:25 PM

Re: Ampeg Heater Circuit Questions

4/22/2000 2:34 PM
andyfuchs	Re: Ampeg Heater Circuit Questions I remembered an old Scott audio trick: They actually used their 4 12AX7's in the preamps, to function as the cathode resistors for their output tubes. I think they used 7189 or EL84's. They put them in series with a cap across them, and they were very quiet. An old timer I worked with at the time said that, "this is the quietest DC filament supply you could get at the time". I assume this was because you didn't have DC regulators like we do today (practical ones at least). Cool concept.

4/22/2000 2:34 PM

andyfuchs

Re: Ampeg Heater Circuit Questions

I remembered an old Scott audio trick: They actually used their 4 12AX7's in the preamps, to function as the cathode resistors for their output tubes. I think they used 7189 or EL84's. They put them in series with a cap across them, and they were very quiet. An old timer I worked with at the time said that, "this is the quietest DC filament supply you could get at the time". I assume this was because you didn't have DC regulators like we do today (practical ones at least). Cool concept.

Replies:

Ray Ivers Scott Heaters for PA Cathode Resistors -- 4/22/2000 3:02 PM
Doc Re: Ampeg Heater Circuit Questions -- 4/24/2000 6:17 PM