18W Tremolo TMB Xtra Gain build

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JMPGuitars
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Re: 18W Tremolo TMB Xtra Gain build

Post by JMPGuitars »

Your schematic is showing 470K grid leaks on the power tubes. Switch those to 220K and see how it sounds.
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Re: 18W Tremolo TMB Xtra Gain build

Post by Bieworm »

JMPGuitars wrote:
Thu 02/24/22 11:25 am
Your schematic is showing 470K grid leaks on the power tubes. Switch those to 220K and see how it sounds.
Thanks Josh... but I would like to maintain the Tremolo TMB sound when in parallel mode.
Will give it a shot anyway.. although it's a vox thang 😃
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Re: 18W Tremolo TMB Xtra Gain build

Post by Bieworm »

Sorry Josh.. but I tried a 100k Xtra Gain pot and it's spot on! Really nice crunch now.. even on full on dial. This is with the A500k Gain pot at 3 o'clock and the A100k Xtra Gain pot at 2 o'clock... rock on!!!

https://www.dropbox.com/s/ibba6h3d4iqr1 ... t.m4a?dl=0
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Re: 18W Tremolo TMB Xtra Gain build

Post by JMPGuitars »

Bieworm wrote:
Thu 02/24/22 2:13 pm
Sorry Josh.. but I tried a 100k Xtra Gain pot and it's spot on! Really nice crunch now.. even on full on dial. This is with the A500k Gain pot at 3 o'clock and the A100k Xtra Gain pot at 2 o'clock... rock on!!!

https://www.dropbox.com/s/ibba6h3d4iqr1 ... t.m4a?dl=0
lol, no need to apologize. You can compensate for the gain issue in the preamp (which you did) or you can compensate in the power amp (or both). You may find you like it better one way or another, but you'll never know if you don't try. 😉
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Re: 18W Tremolo TMB Xtra Gain build

Post by Bieworm »

JMPGuitars wrote:
Thu 02/24/22 4:32 pm
Bieworm wrote:
Thu 02/24/22 2:13 pm
Sorry Josh.. but I tried a 100k Xtra Gain pot and it's spot on! Really nice crunch now.. even on full on dial. This is with the A500k Gain pot at 3 o'clock and the A100k Xtra Gain pot at 2 o'clock... rock on!!!

https://www.dropbox.com/s/ibba6h3d4iqr1 ... t.m4a?dl=0
lol, no need to apologize. You can compensate for the gain issue in the preamp (which you did) or you can compensate in the power amp (or both). You may find you like it better one way or another, but you'll never know if you don't try. 😉
you're right! it's pretty easy to try when I parallel another 470k resistor with the EL84 grid leak resistors..
thanks for your input!
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Re: 18W Tremolo TMB Xtra Gain build

Post by JMPGuitars »

Bieworm wrote:
Fri 02/25/22 4:39 am
you're right! it's pretty easy to try when I parallel another 470k resistor with the EL84 grid leak resistors..
thanks for your input!
Another thing you can do is the stupid simple master volume. Play around, and when you're done, measure the resistance you like the best at the grid leaks.
Stupid Simple Master Volume.jpg
Obviously if you drop the volume with that too much, you lose power amp distortion.

Thanks,
Josh
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