Ultra-simple panning in audio mixer: Not working as expected

[envytea]

Hey all,

I am making a whole bunch of MFOS modules. Included is this:

http://musicfromouterspace.com/analogsynth/stereomixer.html

I expanded it to eight channels- which is perfect for my needs for now... I put it all together yesterday. It works okay, but the volume adjustment doesn't diminish the level to zero sound, and the panning is not wholly effective. I'd like the volume to go to total silence at "0", and I want the panning to go full silence to each side (i.e. all in the left, silence in the right and vice versa). It is kinda close, but not sufficient. I have everything as described in Ray's schematic- substituted 22k resistors for the 20k, and the 39k amp resistor is now a 33k. Nothing too major of a difference, right? Has anyone built this, had better results? What can I do to make it better? I think I should switch the 50k panning pots to 100k... Good idea? Maybe make the volume pot bigger too? Like 250k? What do you think?

Thanks!