A/B switcher mixer;Q about popping.

[sean k]

Below is the schematic by RG Keen but I've added a bunch of switches and some pots to hve certain things happen.Basically the first switch allows you to earth the outputs and check tuning.Next along is a chioce between mixing the two outputs through a dual ganged pot or having one or the other outputs on with 4DPT switch.The stomp switch selects which is on or off.So its pretty straightforward but I'm unsure where to hang resistors to ground to stop popping.My gues is that all the contcts after the 100uf cap will be culprits so maybe the only place I need a high value resistor to ground is right off the neg side of the 100uf.
 Can anyone offer any other places that may need something done to stop potential(pun intended)popping.

[R.G.]

I personally would move the 100uF/0.1uF to right after the 100 ohm resistor out of the opamp. The 2.2M that's always connected to it then will prevent DC levels on the output of the caps. All the rest of the signal path is DC grounded if I'm reading it correctly, so the only place left for popping is shared-ground pops from the LED currents.

[sean k]

Thanks RG,so what if I have the 9V supply for the LED's going through a 100ohm resistor with an extra 47uf cap to ground and,this is an idea,have the LED's on a lifted ground together and then maybe a 22ohm resistor to chassis ground or do they simply need a diode,1N4001,going accross them in opposing bias or a high value resistor?