Is this madness? A looper that'll switch an effect from in front of amp to loop?

[iaresee]

I sat down to draw this out thinking, "Oh a nice 4PDT and I'm done" -- but no! It's trickier than that. You can just send the in/out from one set of jacks to the loop and then the other, you also need to pass through the pair of in/out jacks not being sent to the loop so you don't break the signal. Urg.

Here's the background: picked up an Eventide ModFactor yesterday and it's a pretty sweet pedal. Compact given what it does and the sounds range from decent to outstanding (the Leslie sim is out of this world, ditto for their Univibe phaser factory preset). Trouble is: sometimes I like my modulation in effects right up front of my amp, first in line (for example most times this is where I like my wah) and sometimes I like my modulation effects in the loop, after all the overdrive and distortion and preamp stuff has been added to it.

I have to admit I was really hoping that the ModFactor, like the TimeFactor, would let you run independant effects on the left and right channels. That would have been sweet. I could have used the right channel for the front-of-amp path and the left for the loop path and just built my patches around hard-panned effects. But alas: no dice. It does do stereo, but you can only run one effect at a time and it gets applied to the left and right channels however Eventide thought it'd be best.

So I'm trying to think up a box that will, with a stomp, let me switch the place of the ModFactor. I'm running it in mono so that simplifies things a bit. A 4PDT would certainly let me run two paths through a loop, but it doesn't help me connect the unused path's input directly to output. I think I'm going to have to go IC relay here to do this. It definitely needs more thought. But before I go down this path I have to ask: anyone tried this before? Is it madness?

[slacker]

I don't think it's madness, personally it's not something I'd bother with though. I think for practice and recording I'd just be happy to plug and unplug it and live I'd just stick it in one position and live with the compromise.

If you don't need an LED you can do it with a 4PDT stomp, if you like I can knock up a schematic. If you can life without it being a stomp switch you could do it with a rotary switch and that would let you have an LED, unless you need to switch it half way through a song that's how I'd do it.

[iaresee]

I don't think it's madness, personally it's not something I'd bother with though. I think for practice and recording I'd just be happy to plug and unplug it and live I'd just stick it in one position and live with the compromise.

Compromise? That's very much counter to my OCD though!

If you don't need an LED you can do it with a 4PDT stomp, if you like I can knock up a schematic. If you can life without it being a stomp switch you could do it with a rotary switch and that would let you have an LED, unless you need to switch it half way through a song that's how I'd do it.

I'll post my schematic with a 4PDT that I did last night and we can compare notes. I'm curious to see how you'd do it. I have it switching ground completely out and maybe I don't need to do that.

And I'm not dead set on a stomp since changing it up mid-song is an unlikely scenario. It's more a between song flip.

[slacker]

My way just switches the signal, I can't see a problem with that.

[slacker]

Here you go.



I haven't shown the grounds or the jacks but hopefully it makes sense. The lines don't join where they cross.

[iaresee]

I assumed no common ground in mine so I'm not just switching the signals from the tips of the jacks, but the sleeves as well. That's why I couldn't see a way to do it with a 4PDT. I don't know if it's a generally okay thing to tie the grounds together on those paths.

[slacker]

The left hand side is just like a true bypass loop so tying those grounds together will be fine.
I think if you get problems with ground loops you can just lift the ground to one or both of the jacks that will be in the amp's effects loop. The mod factor will already be grounded by the lead going to the amp input so I'm pretty sure it's Ok to do that but you might want to wait for someone with more expertise to come along

[iaresee]

Ian, thanks man. Can anyone confirm that it's cool to tie the grounds of your input and your f/x loop together?

And here's what I drew last night before posting that when I realized a 4PDT wasn't going to cut it. I could build one really big Wicked Switch I suppose.

[iaresee]

Update: got the block diagram for my Twintone and it's useless. Doesn't really tell me if the input ground and the f/x loop ground are the same in the amp.

[FlyingZ]

Can anyone confirm that it's cool to tie the grounds of your input and your f/x loop together?

Worked for me. Mine activates an effects loop and a preamp loop with one unit.
A diode or cap across the relay will help a little with the pop. If I ever get into mine again I might try a 2.2M to ground because it seems relay coils build up some kind of charge that dissipates after a couple activations, still acceptable.
EDIT: oops, thought I saw a relay