Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Colas LeGrippa on December 28, 2021, 06:34:45 pm
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I just finished another tube overdrive stompbox and I was very surprised to see that a 12AU7 yields out more power than a 12AX7. Someone can tell me why ?
Here ls the schematics I just drawn
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More pics
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Regulated power supply
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Omg, not exactly the same dimensions as the original one.....😀
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a 12AU7 yields out more power than a 12AX7. Someone can tell me why ?
Cuz the datasheet says so
1.2W pd ax
2.75W pd au
If you mean louder, can't help ya there :icon_biggrin:
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Much louder, by 50 percent..I did mot think a low voltage stompbox would scrape off the paint from my walls like this one does.
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> surprised to see that a 12AU7 yields out more power than a 12AX7
AU conducts better. Passes more current. At a mere 12V, that counts for a LOT.
The old-guy guide was to run a B+ at least as high as the tube Mu. Otherwise the bias is unstable. 12AX7 should have 100V supply. 12AU7 is from a family which often found itself on a 22.5V battery. The guide hides some assumptions, and late Tung-Sol could do some better. But good to keep in mind.
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I'll keep that in mind that' s for sure.
Thanks for explanations.
Coppola.