Stereo to Mono Sum box?

[jwseong]

I want to use my effect pedals in stereo now, but I might run mono output sometimes, but my BOSS RV-5 (Which is last in chain) won't sum to mono.
Could you show me schematic/advices? Thank you!

[induction]

The simplest solution is a few resistors in a passive summing box. Read this. You may have to play with resistor values. I'm not familiar with the Boss RV-5, but I assume both outputs are buffered, which is good. You'll want a low output impedance for this to work well.

If you want to get more complicated, give this a whirl. (Here's the schematic.) If you don't need to control the level of each side independently, then you can replace the volume pots with 10k resistors to ground, tapped from the input side.

[Muadzin]

I do wonder though, if you're output is going to be mono anyway, what advantage is there in hooking up your stereo effects in stereo as opposed to just hooking them up mono. Which even the RV-5 has as a capability.