GCX has hum and noise even on bypassed loops

[VncRockstar]

Friends, and Gurus,
So I just finished wiring up my monster rack with George L's, after transplanting a simplified version from a four space rack box, but now I am experiencing the same horrendous hum/buzzing noise, that I had previously eliminated with the use of plastic shoulder washers (like Humfree rack ears), but this time it won't go away. I have narrowed it down to the GCX switcher (both of them).

I disconnected the internal ground in the GCX after talking to John Clark at Voodoo Lab. It was worse!
*Tried using only one with my Stiletto and then my Rectifier.
*Eliminated each pedal onle by one. *Swapped GCX-1 for GCX-2 in hope that I might find one was worse than the over.
Tried unscrewing it from the rack rails and suspending it on a sheet of foam.

Is it possible to wire in a grounding wire for the rack?
Anybody else have a simliar problem?
Check out my rack here:
http://www.voodoolab.com/forum/viewtopi ... p=179#p179

Thank you for visiting,
Reuben Valdez

[Josh Fiden]

Keep unplugging things until you find the very simplest configuration that still makes noise. Then look at how each remaining device is being powered. Check and swap out the remaining cables, those solderless ends can be a problem if you're not very careful cutting and assembling them.

Also, on the GCX try patching through the front panel input. That will tie the chassis to audio ground.

Post what you find!

Thanks,
Josh Fiden
Founder / CEO

[VncRockstar]

Also, on the GCX try patching through the front panel input. That will tie the chassis to audio ground.

Post what you find!

Thanks,
Josh Fiden
Founder / CEO

Josh,
I did check every solder-less cable before completing my set-up. I'm pretty sure they are all good, because I swapped/used my standard cables when I did my trouble shooting in my previous attempt [and still had hum from both GCX units], but I will do it all again to confirm. I just don't understand how I would get any noise if the GCX unit is all true-bypass.

Anyhow, regarding your above comment: How should I patch through the front panel input, as you say, to tie the chassis to audio ground [in detail]? Isn't that the standard way to plug in? Is there another way to "tie the chasis to audio ground?

The hum is only on the front end (Guitar to GCX to 4-pedals Loops 1-4 to amp input). I just added the Pedal Power 2 Plus and have eliminated a 2nd mesa from the set-up till I fix the hum problem. FX Loop is still noiseless.

See Picutes below...
(It's much cleaner now with PP2+)

[Josh Fiden]

The GCX does not cause hum. It is simply a set of connections. If that set of connections produces noise, the same set of connections without the GCX will also produce noise.

Here are your instructions from my post 2-1/2 weeks ago:
"Keep unplugging things until you find the very simplest configuration that still makes noise."

Until you do this, further discussion about whether or not you think your cables are okay is a waste of time. Start unplugging. Do it now. Every time you find something you can unplug and the noise remains, you have made progress. Leave that out and keep unplugging.

We're all waiting......

Josh Fiden
Founder / CEO

[VncRockstar]

Josh,
It's gone! Holy s*** as soon as I took the Korg tuner out of the the "Feed Through" it was gone. I also tried to send [To: tuner] with the "Guitar Out" and the noise came back (tried different cables too).

Now I need to know how to get a tuner in the loop. I thought that was the best way. I guess not. I would assume the DTR-2 is an industry standard that even Voodoo Lab techs use for the Pros racks; any suggestions to solving that problem?

Also, thank you for the quick response.

-Reuben-
Vncrockstar

[Josh Fiden]

Josh,
It's gone! Holy s*** as soon as I took the Korg tuner out of the the "Feed Through" it was gone. I also tried to send [To: tuner] with the "Guitar Out" and the noise came back (tried different cables too).

Now I need to know how to get a tuner in the loop. I thought that was the best way. I guess not. I would assume the DTR-2 is an industry standard that even Voodoo Lab techs use for the Pros racks; any suggestions to solving that problem?

Also, thank you for the quick response.

-Reuben-
Vncrockstar

Good work! You're almost done. The problem is a ground loop with the tuner completing the circuit. The tuner has 3 possible connections to ground: audio input, rack rails, and power (AC line input). Try isolating from the rack rails and/or cutting the ground on the audio input cable.

Josh Fiden
Founder / CEO

[tchopper]

Josh,
It's gone! Holy s*** as soon as I took the Korg tuner out of the the "Feed Through" it was gone. I also tried to send [To: tuner] with the "Guitar Out" and the noise came back (tried different cables too).

Now I need to know how to get a tuner in the loop. I thought that was the best way. I guess not. I would assume the DTR-2 is an industry standard that even Voodoo Lab techs use for the Pros racks; any suggestions to solving that problem?

Also, thank you for the quick response.

-Reuben-
Vncrockstar

Good work! You're almost done. The problem is a ground loop with the tuner completing the circuit. The tuner has 3 possible connections to ground: audio input, rack rails, and power (AC line input). Try isolating from the rack rails and/or cutting the ground on the audio input cable.

Josh Fiden
Founder / CEO

Josh - I have this exact same problem (with my Korg DTR-2). I've isolated the unit from the rack and I'm 99.9% sure its not due to the AC line, which would appear to leave the problem at the audio input. If that is true, what would you suggest as the best remedy?

Ultimately, I'd prefer the DTR first in the signal chain to make use of its MUTE capability for silent tuning. Conversely, if I were to just run a split signal from the GCX to the DTR and not have the signal return to the patch that would feed the poweramp, should that eliminate any grounding hum?

thanks!

Tom

[VncRockstar]

Tom,
Good day. I didn't realize that I failed to update my final victory over this DTR-2 Tuner issue. The final fix and solution is really funny and didn't require the $550+ in accessories (George L's solderless custom size cables, Hear-O's rack ear isolators, and other misc stuff) and hardware (Voodoo Lab Power Plus2) that I Invested in to solver the problem; which ironically didn't not solve it. I am however, very happy I persued a much cleaner tone path.

Are you ready for it? Simply clip or unsoldier the "ground" lead on your 1/4inch cable going into the Korg DTR-2 and isolated it with electrical tape. That's it my friend! After that, just a little Voodoo. Haha.

BTW. Here's how I had mine connected:
GCX 2 (my 2nd one, which is also active) Guitar THRU to Korg DTR-2 rear input
So there was a constant (muted) clean signal running to the tuner at all times.

Of course, since the "Persuit of Tone" is a never ending journey and growing life experience, I eventually ditched the Korg, replacing it with a TC Electrronic Polytune, the Tuner function on the TC G-Major2 (which I now use for Harmony) and also use a handheld tuner and expanded my setup with more pedals and insane GCX and wiring setups. I find mine to be one of the most fascinating Voodoo Lab wiring/diagrams I've ever seen. I will post a couple sample pictures and we can exchange E-mails if you're still looking for advice.

Oh man hope this came out right. I did it all from my cell phone.

Reuben
VncRockstar

[tchopper]

Tom,
Good day. I didn't realize that I failed to update my final victory over this DTR-2 Tuner issue. The final fix and solution is really funny and didn't require the $550+ in accessories (George L's solderless custom size cables, Hear-O's rack ear isolators, and other misc stuff) and hardware (Voodoo Lab Power Plus2) that I Invested in to solver the problem; which ironically didn't not solve it. I am however, very happy I persued a much cleaner tone path.

Are you ready for it? Simply clip or unsoldier the "ground" lead on your 1/4inch cable going into the Korg DTR-2 and isolated it with electrical tape. That's it my friend! After that, just a little Voodoo. Haha.

BTW. Here's how I had mine connected:
GCX 2 (my 2nd one, which is also active) Guitar THRU to Korg DTR-2 rear input
So there was a constant (muted) clean signal running to the tuner at all times.

Of course, since the "Persuit of Tone" is a never ending journey and growing life experience, I eventually ditched the Korg, replacing it with a TC Electrronic Polytune, the Tuner function on the TC G-Major2 (which I now use for Harmony) and also use a handheld tuner and expanded my setup with more pedals and insane GCX and wiring setups. I find mine to be one of the most fascinating Voodoo Lab wiring/diagrams I've ever seen. I will post a couple sample pictures and we can exchange E-mails if you're still looking for advice.

Oh man hope this came out right. I did it all from my cell phone.

Reuben
VncRockstar

Reuben

Thanks dude! That was gonna be my last resort, but didn't wanna try it until I had heard something from someone that actually did it.

thanks man!

and yeah - I'd definitely be interested is checking out some of you rack/gear pics/diagrams

Thanks again

Tom