Oh boy, do I love figuring out how to wire switches to reroute stuff Not very beutified, but here goes.
Let me say that seeing this, I would strongly recoment at least one buffer on the input and shielded cables for at least input and output. That is for the builder to decide of course. Some floating inputs and outputs there that I don't really like but I think it's the only way to make this happen with mechanical switching.
First diagram shows wiring WITHOUT grounding of loops inputs when not in use. That may as well work but poping may occure when switching between A B or Y.
At first I thought it would be tough to implement input grounding on this concept but I did it like this: Ground connects to the A/B switch inputs only when the other switch is in A/B position. Extra ground provided to the switch for constant led function though. And with of course another 4PDT switch :)
Sorry for huge images, you can always right click and "open image in new tab" for better viewing.
Thank you! At a first look both the layouts seem ok.
I tried to drawn by myself, but I really can't do it without a 4PDT, that I thought I didn't have to use it, I don't know why.
I pay the 4PDT footswitch a lot, but I'd prefer the grounded loop version.
I could try the not grounded loop first, and in case of pop noise can I use a 1M resistor between the input and the ground? I'm thinking about a pair of position on the MAster Bypass switch, but in case, where you will place this resistor?
Yeah, 4PDTs are generally more expensive, cluncky, stiff, you name it... Only way to avoid using them is ommiting the leds, but that can turn out pretty confusing while operating. Of course the best way would be to get some logic circuit working with relays. That could be programmed to do anyting and far better than simple mechanical switching and with more than one loops. Of course cost goes up and you may have to do extended research to find exactly what you want for diy.
Another good solution would be to just have one independant switch for each loop instead of the AB and Y switch. Not quite the same functionality but I would prefer it to be honest. This way you could also get rid of the extra bypass switch.
I don't think pulldown resistors will help here, the effects in the loop will contain them anyway. This is about noise that may generate in the loop while the input's flowing. Grounded input equals a quite loop :)