Amp switcher help

[trickpony]

I am trying to figure out how to make an amp switching pedal that will switch both the pre amp effects (dist etc) and the effects loop ones (modulation etc) with 1 pedal and hopefully 1 stomp switch. Tell me if this sounds right.

1) IN of amp1
2) Output of pre amp effects
3) In of amp2

4) Send of amp 1
5) input of 1st modulation effect
6) Send of amp 2

7) return of amp 1
output of last mod effect
9) return of amp 2

My question is how should I be grounding this? Do the grounds need to be switching too. Do I need to worry about any situation where both amps are on at the same time.

Sorry this all seems like it should be obvious but I am having difficulties
Thanks,
Ben

[trickpony]

Ok, maybe I rambled...I'll make one more try.

1) When switching between amp inputs do I need to switch the grounds so that the ground from amp1 is isolated from the ground of amp2.

2) same question but when switching between amp effects loops send and returns

Thanks,
Ben

[jkokura]

When switching between amps, you always have the potential for ground loops. Proper amp switching usually uses transformers to decouple the grounds of the outputs from each other. I think RG Keen has an article on his website, and BYOC has a kit I know you can build. I've got a few PCBs for a design I implemented in studying both of those, so you should look at them too.

As for effects loops... similar issue. I think it's easier to put either everything into one amp using it's effect loop, or put everything in front of two amps without using the effects loops.

Jacob