GCX w/MIDI, mic switching

Q & A for building and interfacing your rack gear with Ground Control Pro and GCX-based systems.
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Joined: Fri Apr 07, 2017 2:04 am

GCX w/MIDI, mic switching

Post by gncgry » Fri Apr 07, 2017 2:24 am

Hi all, I'm using 2 vocal mics and sum them into a vocal processor. On stage, due to unwanted feedback, I'd like to be switching between two using my new GCX switcher.

Though I have a problem with routing, even though in theory it should work, it doesn't.

My first signal flow was:
Mic.1 -> Loop 1 in
Mic.2 -> Loop 1 Return
Out -> Loop 1 Out -> Vocal Processor.

So when Loop 1 is off, mic.1 would be active and when loop 1 is on, mic.2 would. But I get a huge noise from the output when the loop is active.

Second try was:
Mic.1 -> Loop 1 in
Out -> Loop 1 Send
Mic.2 -> Loop 2 in
Out -> Loop 2 Send
with a Y cable, merge Loop 1 and 2 sends -> Vocal processor.

So when Loop 1 is active, mic.1 is and when Loop 2, mic.2 would be. Though this doesn't work either.

What do you guys think? any other signal flow ideas?

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Joined: Tue May 05, 2009 2:33 pm
Location: The Lab

Re: GCX w/MIDI, mic switching

Post by JohnClark » Fri Apr 07, 2017 11:13 am

The reason routing #1 doesn't work is because the Return is ground lifted. If you connected a wire from the sleeve of the Mic #2 cable to the Sleeve of the cable connected to Loop 1 Out, all should work as intended.

Routing #2 doesn't work because the Send jack shorts the Tip to the Sleeve when a Loop is Off. Since you used a Y-Cable from both Sends it is getting shorted to ground whenever one of the two loops is Off.

I hope that helps!

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