Multiple Destinations Switching with RG-16

B

bkrumme

Member
I think this will work, I just want some input.

I'm currently using an RG-16 with my Mesa Mark V, G-Major 2, and a couple stomp boxes. My guitars also have piezo systems installed and I'm using an insert/split cable at the "From Front" jack to split the stereo signal to magnetic and piezo.

What I'd like to know is if I can use Loop 8 to choose between destinations for the piezo output of my guitars. Here's how I would connect everything:

Guitar is plugged into the front RG-16 input and is split at the From Front output to the buffer and loop 8. My magnetic signal continues from the buffer and is irrelevant from here out. The piezo signal is plugged into the Loop 8 input. Loop 8 send is patched to a DI box, and Loop 8 output is patched to my acoustic amp. Nothing is connected to Loop 8 return

If this is correct (and appropriate), when I turn on Loop 8, the piezo signal should be routed to the DI box and when I turn loop 8 off it should be routed to my Acoustic amplifier.
 
That won't actually work the way you intend. You will either get the signal coming out of the output (loop off) or the signal coming out both the output and send jacks (loop on). To get it working the way you want, you'll need to plug a grounded plug into the return jack, or to use two loops.
 
OK. So I could just ground a plug out by soldering a lead between the ground clip and center clip, put that in the return jack, and I should be good to go?
 
Yep, that'll work. I do a similar trick as a mute switch on my Effect Gizmo (I use the first 4 loops as an input selector).
 
Actually it's not that simple, unfortunately... The problem is that the return jacks on the RG-16 do not have a ground. This was originally intended to prevent ground loops, but it turns out it doesn't help all that much. We added the grounds when creating the Effect Gizmo, but have not yet updated the RG-16 to add them.

As a result, you'll end up with a floating signal and you'll probably get some noise. There are two ways to fix it - modify the RG-16 to add the grounds (not too hard to do if you have soldering skills), or to create a cable that has the ground of one connector connected to the tip of the other connector. You'll have to find a grounded jack on the RG-16 - the send of an unused loop or one of the buffer jacks or the tuner output jack if you're not using them. There are other ways to do it if you are using the buffer and all loops, but it gets a little trickier.
 
If it's one of loops 5 through 8, make sure that the loop is connected in your audio path. For example, If you're not using loop 7, but you're using loops 1 through 6, connect the output of loop 6 to the input of loop 7. Connect the output of loop 7 to your amp. Connect Send 7 using the grounding cable to Return 8. This will provide a good ground and will mute things correctly when you switch loop 8 on.

Loops 1-4 are already connected in series, so you can use any of those sends as a grounding point without any other connections.
 
rjmmusic said:
That won't actually work the way you intend. You will either get the signal coming out of the output (loop off) or the signal coming out both the output and send jacks (loop on). To get it working the way you want, you'll need to plug a grounded plug into the return jack, or to use two loops.
Click to expand...

How do you get the signal coming out of the output when loop is off?

Thank you very much
 
That's how loops work! When the loop's off, the signal goes straight from the input to the output. When the loop's on, it goes via the send and return of the loop.
 
Ah ok, no problem :)

The send is half-normalled to the output. What this means is that the signal will go to both jacks unless a jack is inserted into the return socket, which breaks the connection. It's a similar trick as is often used in patchbays in studios. I seem to recall there being a good description of it in the manual of the Behringer PX2000 patchbay (hey, maybe something good can come out of Behringer after all :))
 
Thanks for your answer. I didn't know it was half-normalled.

rjmmusic said:
Actually it's not that simple, unfortunately... The problem is that the return jacks on the RG-16 do not have a ground. This was originally intended to prevent ground loops, but it turns out it doesn't help all that much. We added the grounds when creating the Effect Gizmo, but have not yet updated the RG-16 to add them.

As a result, you'll end up with a floating signal and you'll probably get some noise. There are two ways to fix it - modify the RG-16 to add the grounds (not too hard to do if you have soldering skills), or to create a cable that has the ground of one connector connected to the tip of the other connector. You'll have to find a grounded jack on the RG-16 - the send of an unused loop or one of the buffer jacks or the tuner output jack if you're not using them. There are other ways to do it if you are using the buffer and all loops, but it gets a little trickier.
Click to expand...

If return is grounded, then you make a ground loop with every pedal you connect, don't you? Doesn't it matter? Doesn't it produce hum noise?

Thanks a lot.
 
Technically, you could call it a ground loop. In practice, it doesn't seem to cause hum like a ground loop involving the power supply does. The only time I've seen problems is when running long cables to an amp's effects loop and back.
 
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