milobender wrote:Has anyone actually tried this schematic? I'm having problems with it right now... It works marginally at the ends of the blend pot rotation, but the entire middle drops volume so low it is unusable. I contacted Scott and he suggested it was a phase problem, which I can see, but his suggestion of switching the pot wiring around (which I've tried some to no avail) doesn't make sense to me... if one part of the signal goes directly to the effects, and another splits back thru the pot to the return side of the switch, isn't a 'phase issue' inevitable? Anyway, any thoughts would be appreciated... I may just be blind here...
EDIT: sorry, the circuit diagram wasn't appearing before and I didn't see that the circuit was using a "normal" 500k linear pot instead of a dual-ganged blend pot. Ignore the part at the bottom.
It may be that 500k is too much resistance. Try putting a 50K-100K (or something like that) resistor across the outside lugs of the blend pot and see if it improves.
EDIT: Ignore everything below this!
You may have the blend pot wired backwards.
A blend pot is like 2 pots that each work for 1/2 of the pot's travel:
Center = both pots at full volume (100%).
CCW = 1st pot at 100%, the 2nd at 0%.
CW = 1st pot at 0%, the 2nd at 100%.
Anything in between = 1 pot at 100%, the other between 0-100%
IOW a blend pot is properly wired so that it only reduces one (or the other) of the 2 signals for 1/2 of the pots travel, and the other signal is at 100%.
If you wire it backwards (meaning the 2 sets of outer lugs are reversed), you will get 0% in the middle and only
get full output of one signal at fully CW or CCW.