Dual Overdrive With One Input And Two Individual Outputs For Two Amps - Is It Possible?

[travisthemute]

Hey guys! First time posting but I'm a frequent visitor. I can usually find the answer I'm looking for thanks to you guys but this one has me stumped. I'm hoping I can get some assistance with this one: I'm working on a pedal for a buddy and he asked me to build him a Tubescreamer/808 style pedal. The problem is he uses two amps when playing live so I originally thought about going the AMZ splitter route and basically having a single TS circuit in the box. Tonight I had the "bright" idea to maybe house two separate circuits in one enclosure (mainly because it's cool as hell but also I feel like it should eliminate some of my concerns about phasing issues) but I can't seem to find anyone having done this specifically. I've definitely been through the whole "why the F&@# would you do this?" but maybe it could be cool? Ideally there would only be the need for a single 3DPT but I couldn't wrap my head around that being even possible. Any pointers on how to have two circuits with individual outputs work with a single input? I'm attaching what is my probably hella wrong guess at what the wiring would look like but I'd really appreciate some guidance! Thanks in advance for any insight/assistance!

 

[Feral Feline]

You should look at topics about running two amps and shared grounds and hum; isolated splitters would be another good topic to bone-up on.

You can have one stomper to bypass both circuits. Simple way that ignores my aforementioned advice would be with a 4PDT.


At the very least, I think you should run a splitter-buffer such as the simple SplitnBlend DIY vero/PCBs from Moonn, GPCB, Fuzzdog, and elsewhere, or an op-amp based splitter from JMK or roll your own w/ ROG's plans — that's if you want to fit it in the same enclosure. Otherwise, look at building your friend the PPCB 3-Ch Splitter, and then you can build the effects into one box with two inputs and outputs and have a 3rd channel as a side-chain for something like a compressor or auto-wah/envelope filter ... but I digress.

So how does your diagram integrate with your friend's dual-amp setup? When the pedal's not in use, how does the signal get split to the two amps, and where would your pedal splice into that when it's engaged and be out of the way when bypassed?


There are solutions to achieve what you wish to accomplish, but obstacles to achieving success have to be assessed.


Take all that with a grain of salt, I've never run a stereo rig. Maybe someone who has would chime in with better advice.

 

[travisthemute]

Thanks for that information! I’ve never been a stereo setup person either so I’m already in a bad position, haha. I originally had tried just bridging an additional output to a Minotaur Sonic Terrors Fuzz & Burn clone I was working on and it passed signal to my two amps when engaged or bypassed, but it very clearly needed to be buffered. That led me down the rabbit hole of deciding which buffer/splitter would be the best fit but I couldn’t find anything that had ground lifts (for ground loops) or phase inversion (for phase issues). That’s kind of where the idea came in to have two different circuits that while similar, should provide enough difference to hopefully mitigate any phase concerns I have.

I’m accepting I may have to build a splitter box, but that doesn’t get rid of my worry about having possible ground loop/phase issues. Would I just need to go with a transformer style splitter? Thanks again for taking the time to explain all of that!

 

[jcpst]

The ppcb splitter has phase switches.

I run a stereo setup. There are the pedals before the stereo split, and after. Everything going into the first guitar amp is mono. Then coming from the amp’s effects loop send, I split and send the effect return to both amps. This way I’m using a single preamp. Of course, there’s many ways to run two amps.

But I don’t think i’d want my OD to be the “split-point”. That feature could be handy though, as long as the pedal behaves like a mono pedal if I only plug in the first output.