Add a blend pot in a GGG tube screamer clone Help!!

[juan_felt]

Hi again,

I want to use a ggg tube screamer with my bass guitar, but I want to be able to add dry signal  to the mix. How can I do this with the pedal I have already built?

Can it be done just with a potentiometer? What I tried was using a 50k linear pot, connecting the first lug to the input jack, the 2 lug to where the pcb output goes in the switch and the third lug to the pcb output. It does work, but when i disconnect the input cable, it starts doing a really annoying feedback.

If anyone could help me, I'd be more than thankful!

Thanks in advance,

Juan

[Kesh]

Just putting a blend pot in allows the output to go back through the full length of the pot and back to the input, giving the feedback you found.

You will need a buffer along the dry signal path, and probably some gain too, as the effected signal of the TS gives out maybe +/- 600mV depending and this may totally swamp your dry signal, depending on what is driving your TS.

The TS circuit is nominally non-inverting, so your buffer should be too. However the many tone circuits in the TS affect phase a lot, so blending will cause cancellation of parts of your signal. My hunch is this will cut bass and treble, so emphasise the middle even more than the TS does already.

[ubersam]

You can try something like what was done in the Voodoo Labs Sparkle Drive (essentially a TS with clean blend). Or you could build a B. Blender and stick your GGG TS in the send/return.

[HOTTUBES]

Does anyone have this B Blender in a Vero layout ??