Bypass on a stereo in stereo out pedal??

[jamierichards1234]

Hi,

New here.. Sorry if this is a really basic question but I couldn't seem to find the answer online      I'm trying to build some stereo fx to use with my synths and wondering how to go about doing the bypass switching? Obviously I could use a 4pdt but that leaves me without an LED and I know from experience that I can't be trusted to operate a pedal without an LED!

Ideally I only want 1 LED and 1 footswitch, but I want to be bypassing what is basically 2 separate effects inside the box. Is millennium bypass the way to go? To be honest I haven't exactly got my head around it yet.

Can anyone point me in the direction of a wiring diagram or schematic for some sort of bypass switching for stereo in/stereo out effects (with an LED) ??

Or do I need to use relays? If so are there any schematics out there for this? I can't be the first person to need to do this!! Unfortunately I've not got anything to dismantle and look at (except my strymon big sky, and I dread to even look in there!

Cheers

Jamie

[Mark Hammer]

The majority of "stereo" pedals are usually modulation or delay-based, with mono in and dual outs.  In those instances, true bypass is not used.  Rather, e-switching is used to simply cancel the effect signal (phase-shift, or delayed) that is mixed in with dry to create a "stereo" out (generally sum and difference).

I'm not saying that's what YOU should do.  Simply noting that this is what many manufacturers do.

There ARE 4PDT stompswitches, but the wisdom of using them would depend on what you want/need your bypass to be, and whether some version of stereo is to be preserved.

[R.G.]

What Mark said.

As an aside, I'd emphasize his comment that you need to be sure you're really doing stereo in and stereo out. If you're really keeping two input streams separated, not generating them, then 4PDT is the minimum that will do. Using the Millenium Bypass may get you the LED if the other requirements for it can be used.

Some side thoughts occur:
* True Bypass; I'm sure you're thinking about true bypass, having heard it endlessly on effects forums. I'll say it again: true bypass is a solution to a problem we mostly don't have any more. True bypass is a fix for pedals that were poorly designed in light of what is now a vast fountain of knowledge about guitars. If you only have synths feeding the effects, they will have an output impedance low enough to not be bothered by pedal loading, so your job gets much easier. You pay for this ease by having to know more about your synth outputs and pedal effects inputs. Tone sucking and true bypass are a magnetic-pickup problem.
* Hard-metal contact switching; if you really are switching synths, not guitars, consider electronic bypass with CMOS or JFET switching. Actually, even if you're switching guitar only, consider solid state switching.
* Relays; relays can make a single switch change any number of contacts. DPDT relays for low signals are about the size of a DIP IC, and cost about $3. Two of them make a 4PDT for $6 more than any footswitch you have or like.

[blackieNYC]

I've done some CMOS switching, and it was cool. But I did build a stereo in and out pedal and decided to put two stomps beside each other. For convenience and some particular space considerations. Each has an LED. It's a vibe, and it can be modulated in tandem or panning. I thought maybe someday I would get cute and turn on one side only.
Just another option.

[thermionix]

I thought maybe someday I would get cute and turn on one side only.

Do it.  One wet out, one dry out is awesome with vibe and trem.