A/B/Y for two channels of the same amp

[sixstringphil]

A friend asked me to build him a switching solution for his new /13 amp. Rather than buy the $275 version with the clean boost and tuner output, would a passive a/b/y do the job for him? I know there are problems with ground loops when using two amps, but this is just to switch between and combine the two channels on the same amp. If it would work, I'd also want to build one for my silverface fender amps.

[MikeH]

I've never had any noise problems switching between 2 channels of the same amp with a standard, passive ABY.  I've mostly done it on fenders.

[sixstringphil]

Thanks Mike. I talked to him this morning and we're going to give it a shot before going to the trouble of building something more complicated.

[m-theory]

You can use a simple A/B for that without problems, though it'd be pretty simple to include a mosfet boost with it, and he'd love you for it! 

[electrosonic]

Not sure about the schematic for that amp. A/B switch is simple enough, but if you build an A/B/Y you might consider if the two channels are in phase - if one channel has  an extra gain stage they might be out of phase.

Andrew.

[sixstringphil]

Well, I threw one together to try and connected it to my silverface Deluxe Reverb. As Andrew warned, the channels on my amp are out of phase (apparently most Fender reverb amps are from what I read). Not sure about his /13. I sent it home with him to try out tonight.