Bypass looper w/ stereo ins and outs?

[Thylacine Dream]

A friend is modifying a baritone LTD Viper for me to give each pickup its own output jack. I'm looking for something that will let me run both outs thru my Bass Whammy near the beginning of my chain, but won't sum the signals to a single mono out after doing so; I still want two distinct chains following the Whammy and ending in two different amps.

What's out there that can do this? I thought a Boss LS-2 might work, but my research pointed no-wards. Also, is there anything I haven't accounted for to worry about - maybe phase issues or somethin?

Thanks for reading and helping

[K2000]

You can buy all kinds of loopers here

https://www.loop-master.com/

[Thylacine Dream]

You can buy all kinds of loopers here

https://www.loop-master.com/

So far I'm not finding what I need there - 2 ins, 2 outs, 1 send, 1 receive

[Dowi]

From what I understand, I don't think it's possible to do what you want. In order to process two separate signals through the same pedal - and keep those separated after it - that pedal must have two ins/outs, but the Whammy is mono iirc.
I don't think there's any looper that can help with this

[D.o.S.]

Yeah Whammy is mono, so you just need to get another one.

[backwardsvoyager]

While I wholeheartedly support the Double Whammy idea, it sounds like you need a true stereo pitch shifter with expression control (H9, PitchFactor, Hedra)

[qersty]

you could do a mid/side thing but i dont know of any pedal which provides this

[voerking]

maybe look at the various Lehle looper/switchers. i can't think of one offhand that does exactly what you need, but there are a ton of them!

[crochambeau]

you could do a mid/side thing but i dont know of any pedal which provides this

Mid/side could work. Sum the two inputs to mono for the single effect send, and then take the difference channel and apply that to the effected whammy return (invert difference plus return for one output, non-invert difference plus return for the other); OR send the difference through effects and then sum to stereo same as before.

A potential issue, which may not apply here, is that the difference channel is engineered to null out when the two channels are mono summed. So if you have a "stereo effects processor" down the line that actually sums to mono before the effects engine you can lose either the nuance between pups or the majority of the whammy depending on how you had signal path configured.

I'll state that I do have a mid/side encode/decode capable circuit designed and in PCB form in front of me (RMA Section). I'm also neck deep in other stuff, so that my tackling this project would take time (of the caliber that should dissuade you, but I'd be happy to take it on if you're super patient), but if another builder wants to run with it to sort out switching and interconnectivity I'm happy to provide some "hardware" and general guidance.

The circuit itself take two inputs (A & B) and outputs a sum channel, a difference channel, another sum channel (each sum can be configured to invert either A or B input, as "decoding" mid/side involves two sum to mono sections, one of which inverts the difference side), and a variable stereo width sending pair based on what came in on channel A and B. True mid/side encode/decode would require two PCBs (see, we're veering into clusterfuck territory here), though this application could get away with one plus an external inverting stage.

Ultimately, this entire episode might simply surpass the realm of being cost effective though. haha

Here's a picture of a built one, the yellow PCB is doing negative power rail duty and is the size of a 9 volt battery for reference.



Again, nothing that solves the immediate issue, but a possible course of action.

[manymanyhaha]

Wish there was a dual mono Whammy in a smaller form factor myself . . . .

But without a dual mono (aka true stereo) Whammy, you would need another Whammy. Or sum the pickups back to mono, then to Bass Whammy, then split them again. Or a box does that but that kind of ruins the point of separate pickup outputs.

Trying to wrap my head around Crochambeau's circuit. Trying to wrap my head around the idea. The side/difference signal wouldn't be affected by the Whammy, right? I read OP's question like they were trying process two signals with a mono effect but keep them separate. Maybe I'm misunderstanding? Sounds like an amazing circuit idea, trying to think how it my be useful to me!

[crochambeau]

The side/difference signal wouldn't be affected by the Whammy, right? I read OP's question like they were trying process two signals with a mono effect but keep them separate. Maybe I'm misunderstanding? Sounds like an amazing circuit idea, trying to think how it my be useful to me!

One of those two signals could be fed to the whammy and then re-united in an attempt to use a mono effect on a "stereo" signal without killing the separation.

I'll try to help understanding (forgive me if I wind up muddying the waters instead)

Instrument has output A and output B.

These two channels are fed into a circuit, which output these channels:
1) A+B (mono sum),
2) A÷B (a monophonic signal that contains neither A or B, but only the differences between them, division is probably not 100% accurate an analog),
3) A-B (which technically is just A+B with either A or B polarity inverted to sort of suck out the common ground without being as heavy handed as "channel 2")
4&5) which is a pair of outputs sweepable between A+B and B+A (two mono channels) to A-B to B-A (two channels pushed to extreme with no "center image") - the center position on the knob amounting to normal A and B unadulterated stereo
6) technically I also included an everything sum channel, but in actuality it's just a noisy mess (included here because the eagle eyes among you can see the obvious additional output on the pictured build.

In thinking about it, channel 2 & 3 are functionally similar, but I believe the result is different. One is set up like a differential instrumentation amplifier, the other is just brute forcing voltage drops across a couple summing resistors before being fed into a bog standard opamp stage. They both null "common" waveforms, so it is entirely possible I overthought this project. Caffeine in the morning is a wonderful thing.

Anyway.

We have two sources.

Let's grab the mono sum 1 and feed the whammy. Whammy does what whammy does and then maybe splits and resistance sums with output 4 & 5 set to widen a bit? that might work, and will certainly result in two different outputs. Though it's possible we're bumping into the realm of cancellation which can effectively shit on bass frequencies.

Maybe feed the sum to whammy as before, and then take the difference channel and resistance mix that to one of the outputs?

Or go true mid/side and sum whammy and difference on one side, and invert difference before summing to whammy on the other? (this one requires an additional inverting stage to accomplish)

Or send the difference to the whammy and choose your return path.

Or set the difference up on its own loop, etc..

All my circuit is doing is some analog "math" between two signals. It does not do multiply, which is ring mod or VCA territory. It really is just a utility stage and not some whiz bang thing on its own (or I would be closer to developing it as a product). It serves as a strange splitter in my world, allowing for some mixing goofiness. It does benefit from truly different signals, as I have been let down while listening to the "stereo output" of say, and old synth, which just makes stereo from a chorus (and as cool as chorus can be, listening to that effect in isolation was not the ripping experience I had hoped for, hahaha). Anyway, if it can be of assistance, it exists as a raw PCB and need only be stuffed with jellybean parts (there is one bodge in which gain setting feedback resistors need small compensating bypass caps to eliminate supersonic oscillation - this will be included when I'm officially selling these as DIY stuff - so knowing guinea pigs only for the moment)

[manymanyhaha]

I have been messing with M/S some on my Master Bus, just sounds good, but this is a dynamic to signal flow that is new to my thinking. Thanks for the patient tutorial!

[Thylacine Dream]

Wow, I'm overwhelmed at the response as well as my own ignorance haha.

For the time being, most of what crochambeau said is over my head, but I'm really interested to see how it all develops!

As for me, I think the Whammy on the bridge pickup only will sound fine, and if it sounds weird I can try subbing in the Pitch Glide on my M9.

But I'm touched n tickled that someone else was already working so hard on something in this area and shared it with us <3