FX Pedal bypass loop box.

[pinto79]

Hey all. I'm hoping someone here can help. I'm wanting to build a pedal switcher / Bypass Loop box that will allow me to use my stereo pedals.

First, a bit of background for clarity: I am using a Marshall JMP-1 Preamp and Peavey Classic 50/50 Power amp for my rig these days. In the effects loop send I go to a mono rack EQ, to a few stomp boxes like my volume pedal, chorus, Phaser, Flanger and my Micro Amp that I use a a boost for solos. After the micro amp I go to a Boss DC-3 Digital Dimension which is a mono in and Stereo out. Unlike most "stereo" pedals, it actually sends a wet signal to each output rathe than the Wet/Dry arrangement of most others. After that I run to my Echo Park which has stereo in and out and then the stereo signal goes to the stereo return of the JMP-1. I really like chorus and other modulation effects and have several of them. Including the DC-3 I have 5 pedals that are stereo in some capacity and I was thinking to build a device that would allow me to connect the mono in and stereo out of each of these pedals to a common mono in/Stereo out, placed between the Micro Amp and the Echo Park, so that I could technically use any or all of them as stereo effects.

I found this attached pic of something that would work mostly as the concept, but was hoping someone who is better at electronic design than I am could provide some insight on how to add the second return to each loop and a second output. I don't necessarily need the master bypass.




Sorry for the long winded post.

Many thanks!


Trevor

[TwilightOdyssey]

Re: FX Pedal bypass loop box.

I believe the entire unit will need to be converted to stereo to work. Someone with more knowledge in this area will have to chime in, though.

The super-clunky version would be to use two loopers controlled via MIDI.

The Lehle d.loop supports stereo operation and can be chained as explained above. They are stellar units (I had two at one time and controlled via a Roland foot switch) but also very pricey.

[dystrust]

Re: FX Pedal bypass loop box.

If you have deep pockets, a Sound Sculpture Switchblade GL offers 16 loops with patch-level software-controlled routing. You can route pairs in stereo, and you can also configure loops in series, parallel or any other combination you can think of. This flexibility doesn't come cheap; they run ~$1500 on the used market. If you're OK with a fixed routing order, a Voodoo Lab GCX or two would get the job done. They're dead easy to program, and can be had relatively cheap on the used market.

I have a slightly more complicated switcher than the one in the OP on my board, and I've considering switching to a GCX and putting my pedals in a rack case several times.

[pinto79]

Re: FX Pedal bypass loop box.

Thanks for the replies. I’ve considered the GCX route but is way more complex than I need.

[PFDarkside]

Re: FX Pedal bypass loop box.

Do you need it switchable on the fly? Is it in a rack?

If it’s rack mounted and you didn’t need to switch on the fly, you could use a multi pole rotary switch.

[pinto79]

Re: FX Pedal bypass loop box.

Do you need it switchable on the fly? Is it in a rack?

If it’s rack mounted and you didn’t need to switch on the fly, you could use a multi pole rotary switch.

I want to attach it to my pedalboard and have the pedals sitting behind it. The stomp switches would be for activating each loop.

[devastone]

Re: FX Pedal bypass loop box.

You will need stereo ins and outs for the stereo signals, all those loops are mono. It will complicate it more, since you need to switch 2 signals with one switch, it will need to incorpate relays, opto-couplers, or something. Or, you can just step on two switches at the same time, but that is weak.

Those switches will also most likely send a pop through the system, it's a common problem with TB switches, they build up a charge while the switch is changing state and it gets released when it latches.

Is there a problem with just running the pedals?

[pinto79]

Re: FX Pedal bypass loop box.

You will need stereo ins and outs for the stereo signals, all those loops are mono. It will complicate it more, since you need to switch 2 signals with one switch, it will need to incorpate relays, opto-couplers, or something. Or, you can just step on two switches at the same time, but that is weak.

Those switches will also most likely send a pop through the system, it's a common problem with TB switches, they build up a charge while the switch is changing state and it gets released when it latches.

Is there a problem with just running the pedals?

I did indicate that the image was just a sample of the idea, and that I was hoping for help to incorporate a stereo return. Better/silent switches would be part of the idea also.

[devastone]

Re: FX Pedal bypass loop box.

Sorry. FWIW, those TPDT switches are probably the best think you can find if you want to keep it all passive, they are what all the cool kids use these days. You could drop the LEDs and use the side of the switch that is turning it on for the 2nd stereo signal, but if you want LED indicators and stereo loops, it will most likely require some active circuitry. Maybe there is a 4PDT switch, but I'm not aware of one. To reduce popping you can use a large (1M or more) resistor across the input and ground lugs of the switches.

I could be wrong, there may be a way to do it passively, but I can't think of anything ATM.

[pinto79]

Re: FX Pedal bypass loop box.

I found a way to do things that is switchless. I'm essentially making a signal path and injecting each pedal into it. A rough mockup was successful, so I'm ordering jacks and wire to make a permanent version. I'll post pics once its done.

[devastone]

Re: FX Pedal bypass loop box.

So you got the stereo thing to work? If so, cool, I'd be interested to see how you did that.

[pinto79]

Re: FX Pedal bypass loop box.

So you got the stereo thing to work? If so, cool, I'd be interested to see how you did that.

I'll try to make a drawing.

[devastone]

Re: FX Pedal bypass loop box.

No rush, I know it's a pain to make drawings, a picture is fine.