Trimpots in a Minibooster stage?

[Bucksears]

I'm thinking about reworking my VoxEXP and MiniTubes layouts to include trimpots to adjust the voltage like the ROG and Electrictabs circuits.

Is this unnecessary in a distortion circuit with Minibooster stages such as the BSIAB, MiniTubes and VoxEXP?

If I COULD put adjustable trimmers in, where would they go? At the drain of the Q receiving the 9v power?

Thanks,
- Buck

[Bucksears]

Bump

[davebungo]

You don't need a trimpot for the minibooster stage because it is fairly predictable unlike single FET amps with a drain and source resistor.  For the latter, you can put a trimmer in the drain or source generally speaking.  If put in the drain, the trimmer will not only adjust the bias but will also have a direct impact on the circuit gain although this may not be very critical.  It just depends on what you are trying to do.  If a circuit doesn't have a trim then it probably doesn't need one by design.

[aron]

It doesn't need it.

What you can experiment with is adjusting the voltages to different stages to get different "feels".

Aron

[Bucksears]

Thanks guys. I guess the only reason I'm asking is because the BSIAB II added an internal trimmer and it uses Minibooster stages.
I'll probably just leave it as-is.

Thanks again,
- Buck