WSG Modification Problem

[reactor]

Hello all.
I finished my build of the WSG and it sounds awesome.
I am now attempting to split Voices A & B onto individual on/off SPST switches so I may hear one voice or the other at the output so I don't always have to utilize both.
This seems like a simple task. Ray's PCB has a trace on the top of the board where both voices meet at the point marked ODD. I cut that trace so the voices are no longer linked. I ran out from the hole on the voice A side to a switch, and out from the hole on voice B side to another switch. I then ran both switches back into a pot that acts as a mixer for the two signals, and dumps it's output back into the circuit right before C1 and R10. I also cut the trace on the PCB ahead of C1 and R10.
This seemed logical, but it doesn't work.
Of greater concern: I cut the two traces on the PCB board as noted. SO, when i removed the added switches and pots and returned to the circuit as designed by Ray, I should receive no sound from either voice (since the ODD link from B to A is cut, and the link from this summing to the filter is cut). However, EVERYTHING still works just as though the traces were not cut. The only notable difference is that the signal from voice B is much lower that it was prior to breaking the trace.
How can this be? Everything has to travel through the filter to get to the output, so cutting out the filter should prevent any signal at the output.
Could there be something wrong with my ground? Is there a filter bypass somewhere in the circuit that I am simply not seeing on the schematic?

Thanks.

reactor.