Splitter pedal: Two guitar amps at once

Splitting the output of your guitar/pedalboard to two separate Guitar Amps is one of the most powerful way in shaping your tone and ‘broaden’ the sound, but to do so you need some tricks. In this post I build a tiny active splitter in to the smallest enclosure possible, splitting the signal keeping it buffered and allowing for both ground-lift and phase-change of one signal to be able to solve for any issues that may happen. When the signal goes to two amps, one of them may themselves, or due to a pedal in its effects loop, change the phase of the signal, meaning in effect your speaker cone goes out when the other amp pulls its cone in, crippling the sound resulting in soundwaves depressing each other. Here I used whatever parts I had on hand to make the box so less than optimal example, but good to quickly have a go at running two amps at once.

First, here are some circuits and layouts to be inspired by. First a stand alone buffer/splitter and then some stand alone buffer/phase changers, now you should be able to follow on in how to mix these together. you need 3x opamp amplifier stages, so a dual and a signal opamp is what you need minimum.   see https://pedalparts.co.uk/  https://effectslayouts.blogspot.com/ or https://www.parasitstudio.se/stripboard-layouts/simple-buffer-and-phase-inverter or https://www.runoffgroove.com/splitter-blend.html 

Next to avoid ground loops adding a spst toggle with isolated output jacks is good to break the connection between the amps if needed. And lastly, tacking on a separate opamp with an spdt bypass switch to invert the signal, all resulted in 3 separate PCB’s usually very helpful when fitting in such a little case. I’m very happy with the results, and it gives a new dynamic to playing, you can keep one amp dry while the other wet with effects, or having two separate amps playing to their different strengths, layering the sound in a very nice way.