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
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.
You can try something like what was done in the Voodoo Labs Sparkle Drive (http://img529.imageshack.us/img529/8590/vlsdkh1.jpg) (essentially a TS with clean blend). Or you could build a B. Blender (http://www.seanm.ca/stomp/bblender.html) and stick your GGG TS in the send/return.
Does anyone have this B Blender in a Vero layout ??