There are already a couple of similar utilities posted. This one is an all-in-one 3-channel buffer, phase inverter, and mixer.
It has 2 wet channels, 1 dry channel, each with independent level controls, a master level, a phase inverter switch (on channel 2), and has a charge pump for more headroom. I'll also add 2 power out jacks (not shown on layout)
It's kind of a 1-trick pony for checking out 1 or 2 effects in parallel, in or out of phase, with or without a clean signal mixed in. Well maybe a 3-trick pony.
I combined 3 Craig Anderton designs: The Spluffer and Mixer from Electronic Projects for Musicians. And the Phase Switcher from DIY Projects for Guitarists. I also added a charge pump to provide +9v/-9v.
I made a couple of minor changes such as adding a 3rd channel to the Spluffer, wiring the clean channel directly to the mixer rather than adding a 3rd set of send/return jacks. I also changed the Spluffer's input cap from 47n to 220n and the Mixer's input caps from 10u to 220n.
It may be useful to increase the Mixer's Gain pot from 10kA to 50kA or maybe even 100kA. I haven't tried this yet, but it will probably help when using effects out of phase as the volume drops considerably. Question is; are there any effects that sound good out of phase? Don't know yet...
Sorry, but I added a bunch of extra cuts and links (and probably extra rows and columns) to keep the offboard wiring short and to keep the link maximum length down to 7. Takes a little longer, but should wire up quick and neat.
I plan to put it in a 125B, with the effect send & return jacks and the DC out jacks on the front. Still working on the faceplate, but something like this.
1978 Gibson Les Paul Standard, Cherry Sunburst