Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: BobL on July 02, 2024, 10:02:47 am
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I have a couple 'deluxe' transformers on hand that I want to use with an AA1164 Princeton Reverb circuit and just want to make sure I'm not missing anything...
PT is Classictone 40-18028. Taps are as follows:
RED 5U4GB 375VDC
RED 5Y3GT 392VDC
RED 5AR4 406VDC
R/W 5U4GB 334VDC
R/W 5Y3GT 354VDC
R/W 5AR4 367VDC
I have these built up as something else right now with a JJ 5Y3S, so I'm thinking I can just keep that and it'll be a good voltage for that circuit? Schematic says 340V.
The OT is a 20W Classictone 40-18090. I should be able to just use this without adjustment, right?
Are there other considerations I need to think about with these transformers and that circuit, or should I be good to go?
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Schematic says 340V.
That’s 340VC (center-tapped), which gets you to about 420VDC with a 5U4G, or even a bit higher with a 5AR4. I have a PR ‘clone’ that runs a B+ of 450. For these voltages, I prefer using JJ6V6S.
The 20W OT will work. If running at higher B+, a 6k6 load with a 12” alnico speaker works better than 8k IMO (which is like a DR output stage). Better for gigging.
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Schematic says 340V.
That’s 340VC (center-tapped), which gets you to about 420VDC with a 5U4G, or even a bit higher with a 5AR4. I have a PR ‘clone’ that runs a B+ of 450. For these voltages, I prefer using JJ6V6S.
The 20W OT will work. If running at higher B+, a 6k6 load with a 12” alnico speaker works better than 8k IMO (which is like a DR output stage). Better for gigging.
This OT is 8K... The amp I'm rebuilding has a pair of 12" speakers in it... I've had PRs with a single 12" and I much prefer that, so will be interested to hear it with a pair of them. Stage volume is usually pretty low for me, though this amp will mostly get used at home for noodlin' and recording demos.