GCX with 2 Pre-amps - Hum & Pop Sounds

Q & A for building and interfacing your rack gear with Ground Control Pro and GCX-based systems.
JohnClark
Posts: 7088
Joined: Tue May 05, 2009 2:33 pm
Location: The Lab

Re: GCX with 2 Pre-amps - Hum & Pop Sounds

Post by JohnClark » Mon May 22, 2017 12:33 pm

It is interesting here that simply adding G-Force seems to create the popping problem.

On early versions of the G-Force the Output didn't reference to ground properly for this sort of setup and would result in a popping sound with any true bypass switch ahead of the G-Force. The fix required someone add a 100K resistor across the output, either inside the G-Force itself OR in the cable connecting to the G-Force Output jack. This was said to be only on very early units... One I have here is from 2002 and it does not need this mod.

I suppose you can start testing by doing your original preamp A/B setup without the G-Force in line and see if it changes at all.

JPRS
Posts: 7
Joined: Sat May 13, 2017 7:53 am

Re: GCX with 2 Pre-amps - Hum & Pop Sounds

Post by JPRS » Thu May 25, 2017 2:20 pm

Interesting indeed.

It is for sure the GForce, popping is gone when it is not connected.

More interesting fact, I switched the order of the GForce & Rocktron, with Rocktron going stereo out into the GForce and GForce going stereo out into the power amp....popping is gone.

I'm happy, now "only" need to redo all patches!

Ahh and hook up the Throttle box again.

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