Question for Techs: Effects Loop Setting

[Blaze]

Playin with 2 amps and A\ B box , i d like to plug the same 3 time-based effects from my pedalboard in each amp own effects loop so they can be independant..

Tried some (Y) mono cord in(send) and out(Return) but seems there s an amp signal that goes in the other amp when i m pushing the A\ B box for amp changing..So this amp plays in both cabs at the time..

The're must be a way but i m not good at this stuff..

Thanks

 

[marnold]

Yeah, even if you are using an A/B, the signal from the one amp that is being used with still go out to the power amp of the amp that isn't being used so you will constantly get a signal from both. Not sure how you'd go about fixing that unless there is an A/B switch with an effects loop built in or with dual inputs.

 

[Ch0jin]

I think it's totally possible, it's just a matter of drawing out the switching and building, or commissioning someone to build, a little loop box. I'll have a play today and post back if I sus it out.

OK I think I have it. You can even get away with a 'standard' 3PDT stomp box switch if you don't bother with LED's to indicated whether your in "A" or "B". Adding an LED indicator is still possible but you'd need a slightly more expensive 4PDT switch and a bi-color LED and (obviously) a power source.

Basically I see it like this.

You'll need a whopping 9 sockets in the loop box for:

1. Guitar in
2. Amp A out
3. Amp B out
4. FX Loop SND A
5. FX Loop SND B
6. FX Loop RTN A
7. FX Loop RTN B
8. FX IN
9. FX Out

Then you wire up a 3PDT switch like this: (using the numbers from above)

2 4 6
1 9 8
3 5 7

If you want an LED and use a 4PDT switch, the signal wiring is the same but I'd use a tri-colour LED in bi-colour "mode" meaning we'd only use red OR green not red AND OR green giving two colours. These babies have three legs and you'd just run power to the middle pole (via a limiting resistor) and connect the other two legs of the LED to the top and bottom poles like this...

2 4 6 "LED Green Anode"
1 9 8 "Power"
3 5 7 "LED Red Anode"

You might need pull down resistors in a couple of places for the FX loop part if there is any "POP" when you switch, but that requires some practical experimentation.

I think that'd all work to do what you want.

 

[Blaze]

Wow that looks good Chojin .. i'll show this to a friend Tech to estimate a cost to this box ..

Great Job !! ..Thanks