18 Watt superlite tmb

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Dabreeze
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18 Watt superlite tmb

Post by Dabreeze »

I recently built this amp and it seems too bright. I changed the cathode bias cap at v1b to 10uf but still sounds bright.. any thoughts about adding a bright cap at the master volume to shunt some highest to ground?
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JMPGuitars
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Re: 18 Watt superlite tmb

Post by JMPGuitars »

Dabreeze wrote:
Sat 06/25/22 4:57 am
I recently built this amp and it seems too bright. I changed the cathode bias cap at v1b to 10uf but still sounds bright.. any thoughts about adding a bright cap at the master volume to shunt some highest to ground?
What speaker are you using?

Which schematic did you follow?
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Re: 18 Watt superlite tmb

Post by Bieworm »

I wouldn't rush into taming the brightness too much. In a live setup you'll need the extra treble.
Things that you could try:
1. Speaker swap like Josh is insinuating in case you have an overly bright speaker in there. If it's a brand new speaker it might still have to be broken in to loose that brittle top end.
2. Add a 50p to 250p snubber cap across the PI plates
3. Put a 100p to 300p cap in parallel with the plate load resistor of V1A.

Those are simple things to try which are not invasive. Fiddle with the values to taste..
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Re: 18 Watt superlite tmb

Post by JMPGuitars »

The other things to consider are the tone stack, which is why I asked which schematic was used. The treble cap and the mid pot value both impact the top end significantly.
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