Building a Wreckish thing for a friend, I will post more info soon.
For now, need to choose a power transformer. He wants to keep costs down so a few cheaper part selections including Russian 6P6S (6V6 equivalents), 6N2P preamp and PI, and ANTEK power transformer.
ANTEK offers 50VA and 100VA torroidals. I've used 50VA for 6AQ5 and 6P1P, I did some experimentation with these and found a fair bit of voltage drop when biased hotter. I think the 6P6S pair would benefit from the more solid 100VA. Based on their load specs, I expect very close to spec B+, possibly even a few volts higher, so rectified, roughly 350VDC for the 250V Pt or 385VDC for the 275V PT.
Any thoughts regarding PT voltage choice in this context? I am unsure how the 6P6S will handle higher voltage. The spec sheet max is 350V. I will be cathode biasing this one.
Wreck-ish build for a friend, build thread.
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mountainhick
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mountainhick
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Re: Wreck-ish build for a friend, build thread.
This amp is build now and the tweaking has commenced. Here's the current schematic:
So posing the question where to tweak for this particular issue.
My friend has onlyu a strat and based on my strats, this amp needs some toning down in ice pick and some fizz. I want to tone down the sharpness and thicken the overdrive a bit.
I already have installed a temporary cut control using a 500K pot and .0047uf cap post PI. Fixed resistor value to be determined. This does help with the ice pick sharpness, but still have fizz.
So ideas, which are bad, good, better, best?
1-Input cap either at jack or attached to first triode grid to ground?
2-Change any values in tone stack?
3-increase grid stopper into thrid stage?
4-plate resistor cap bypass third stage?
5-decrease bias resistor third stage? (Maybe put on a switch)?
6-anything else?
Note: With the hi low function I don't want to alter the first two stages significantly. Don't mind tweaking the tone, but otherwise the Black Face like normal channel function is very nice as is.
Amp in progress:
So posing the question where to tweak for this particular issue.
My friend has onlyu a strat and based on my strats, this amp needs some toning down in ice pick and some fizz. I want to tone down the sharpness and thicken the overdrive a bit.
I already have installed a temporary cut control using a 500K pot and .0047uf cap post PI. Fixed resistor value to be determined. This does help with the ice pick sharpness, but still have fizz.
So ideas, which are bad, good, better, best?
1-Input cap either at jack or attached to first triode grid to ground?
2-Change any values in tone stack?
3-increase grid stopper into thrid stage?
4-plate resistor cap bypass third stage?
5-decrease bias resistor third stage? (Maybe put on a switch)?
6-anything else?
Note: With the hi low function I don't want to alter the first two stages significantly. Don't mind tweaking the tone, but otherwise the Black Face like normal channel function is very nice as is.
Amp in progress:
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Last edited by mountainhick on Fri Aug 14, 2026 3:14 pm, edited 2 times in total.
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sluckey
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Re: Wreck-ish build for a friend, build thread.
Nice build! And I have a fondness for neat hand drawn schematics too. However, your bridge rectifiers are drawn incorrectly.
Sorry, but I have no tweaking ideas.
Sorry, but I have no tweaking ideas.
...Steve
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mountainhick
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Re: Wreck-ish build for a friend, build thread.
I see this is from about a month ago, so I'm curious on what you have implemented since.
I would probably keep that cut control permanent and external. I have hardwired a specific low setting for my presence controls and just put the cut control on the front panel in its place. Although I like it more like a "Brilliance" where clockwise makes it brighter and wired to lugs 1 and 2 of an A250K pot.
As far as additional fizz control, I'd try the plate bypass caps on stage 2 and 3; playing with values between 150p and 680p. You could also try increasing your 47p cap across your PI plates.
I would probably keep that cut control permanent and external. I have hardwired a specific low setting for my presence controls and just put the cut control on the front panel in its place. Although I like it more like a "Brilliance" where clockwise makes it brighter and wired to lugs 1 and 2 of an A250K pot.
As far as additional fizz control, I'd try the plate bypass caps on stage 2 and 3; playing with values between 150p and 680p. You could also try increasing your 47p cap across your PI plates.