Voodoo Lab

GCX Worksheet Help
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Author:  kbrinker [ Sat Jan 06, 2018 10:19 pm ]
Post subject:  GCX Worksheet Help

Hey everyone,

I am looking for someone to take a look at this GCX Worksheet and help me figure out how to wire it. I am wanting to run the Phase 90 and Flanger in front of both EVH heads. The Delay, Chorus, and Reverb need to be run into the effects loops of both EVH heads. Please see the picture below. Any help would be greatly appreciated!!



DD8DB780-BF0E-45A1-B014-A42E52446720.jpeg [ 86.96 KiB | Viewed 393 times ]

Author:  nyteowl [ Mon Jan 08, 2018 4:09 pm ]
Post subject:  Re: GCX Worksheet Help

Hi Kyler,

I've not visited this forum for a couple of years, but before I went MIA I helped a lot of folks with signal routing issues similar to yours. I'd be happy to offer some assistance, but first I have to ask an important question:

Will you be switching between the two EVH heads so as to run only one of them at a time, running both heads simultaneously, or perhaps alternating between those two scenarios? I ask because routing a number of pedals thru the FX loops of two different amplifiers can get rather tricky.


Author:  kbrinker [ Mon Jan 08, 2018 8:52 pm ]
Post subject:  Re: GCX Worksheet Help

Hi Jack,

Thanks for the reply! To answer your question, I plan to run both EVH heads simultaneously. In other words, both amp setups will sound the same.


Author:  nyteowl [ Tue Jan 09, 2018 3:12 pm ]
Post subject:  Re: GCX Worksheet Help

Hey Kyler,

After giving this some thought, I came up with a way to run everything but your Wah pedal in a loop, so if this were my rig, here is what I would do:

As I mentioned earlier, trying to run multiple FX pedals thru two independent FX loops with a single GCX is more than a little tricky, so the first thing I would do is convert 4 of your GCX loops from Mono to Stereo, which will make things WAY easier. You can either send your GCX to Voodoo Lab and have them do the work for you or simply purchase the board and do the work yourself, which is not very difficult at all.

There are 4 loops per board and my preference would be to convert Loops 5 thru 8. If I recall correctly, there is no soldering involved. After removing the nuts and washers from the back panel jacks you just unplug the few connectors that link the daughterboard to the motherboard, swap out the old board for the new board, re-attach the connectors, put the nuts and washers back on and your done.

To make your Mono GCX loop connections you’re going to need 3 or 4 Mono jumper cables, depending on where you decide to put your Wah pedal, and one Y-Jack/Splitter cable. For example purposes let’s say the pedal order is...

TU3 Tuner → Wah Pedal → Phaser → Flanger → Talk Box → EVH Guitar Inputs

...but you can put them in whatever order sounds best to you. Make your connections as follows:

Guitar into the Front Panel Guitar In
Jumper cable from Back Panel Guitar Out to Loop 1 In
Loop 1 Send to TU3 Tuner In
Do NOT connect the TU3 Out jack to the Loop 1 Return. By doing this you remove your guitar signal from the signal chain, guaranteeing silent tuning.
Loop 1 Out to Wah Pedal In. Wah Pedal Out to Loop 2 In. (See Note following this section)
Loop 2 Send/Return to Phaser In/Out.
Jumper cable from Loop 2 Out to Loop 3 In.
Loop 3 Send/Return to Flanger In/Out.
Jumper cable from Loop 3 Out to Loop 4 In.
Loop 4 Send/Return to Talk Box In/Out.
Y-Jack/Splitter cable from Loop 4 Out to EVH Guitar Inputs.

NOTE: The Wah Pedal does NOT Have to go between Loops 1 & 2. You can put it between Loops 2 & 3, Loops 3 & 4 or between Loop 4 and the EVH inputs. If you use the latter option, you’ll need a Jumper cable from Loop 1 Out to Loop 2 In. Connect the Loop 4 Out to the Wah Pedal In and run the Y-Jack/Splitter cable from the Wah Pedal Out to EVH Guitar Inputs.

Conversely, the TU3 can be configured for silent tuning, so you could also choose to put the TU3 on the floor in front of you, plug your guitar directly into it, and run the TU3 Out to the Front Panel Guitar In, which would free up Loop 1 for your Wah Pedal.

Next up are the Stereo FX in the EVH FX Loops. To make these connections you’ll need 3 Stereo jumper cables, 2 mono cables, and 8 Insert cables. Insert cables look like Splitter cables, but they have a single Stereo (TRS) plug on one end and the other end of the cable breaks out into a pair of Mono (TS) plugs, which are usually labeled Left and Right or color coded White and Red. You’ll want to take special care to make sure you don’t cross wire anything in order to keep the FX Loops independent from one another, and thinking of Red as Right will help you stay on track.

The TRS plugs on the Insert Cables go into the Loops 5 thru 8 jacks on your GCX and the TS plugs connect to the Left and Right Ins and Outs of your Stereo effects, and as per your work sheet the FX order for the stereo loops will be as follows:

DD7 → HOF → M183.1 → M183.2

Connect the Stereo Jumper cables to the Out and In Jacks of Loops 5 & 6, 6 & 7, and 7 & 8.

Connect the TRS Plug from Insert Cable 1 to the Loop 5 In Jack.
Connect the TS plugs on the other end of Insert Cable 1 to the FX Send Jacks of the EVH FX Loops.
Connect the TRS Plug from Insert Cable 8 to the Loop 8 Out Jack.
Connect the TS plugs on the other end of Insert Cable 8 to the FX Return Jacks of the EVH FX Loops.

Verify you have the left and right jacks connected correctly, as you definitely do NOT want to route the Send from one FX Loop to the Return of the other.

Connect the TRS plug of Insert Cable 2 to the Loop 5 Send Jack.
Connect the TS Plugs of Insert Cable 2 to the Left and Right (A&B) In jacks of the DD7.
Connect the TS Plugs of Insert Cable 3 to the Left and Right (A&B) Out jacks of the DD7.
Connect the TRS Plug from Insert Cable 3 to the Loop 5 Return Jack.

Using Insert Cables 4 and 5, repeat the above four steps for the HOF in Loop 6.

Connect one end of Mono Cable 1 to the Loop 7 Send Jack
Connect the other end of Mono Cable 1 to the M183.1 In Jack
Connect the TS Plugs of Insert Cable 6 to the Left and Right M183.1 Out jacks.
Connect the TRS Plug of Insert Cable 6 to the Loop 7 Return Jack.

Using Insert Mono Cable 2 and Insert Cable 7, repeat the above 4 steps for the M183.2 in Loop 8.

I’m guessing you’re using two M183 Chorus units so you can dial in two different flavors of stereo chorus (e.g. fast and slow) that you can use as needed independently, but I’m sure you’ll correct me if I’m wrong… ;)

I know this is a lot to wrap your head around - it certainly was for me after being away from this sort of thing for so long – but if you have any questions, let me know.


Author:  kbrinker [ Tue Jan 09, 2018 3:53 pm ]
Post subject:  Re: GCX Worksheet Help

Wow Jack! I can’t thank you enough for all your help!! The final clarifications I need are:

-Is it necessary to put the Wah pedal in a loop? My intent is to keep the Tuner, Wah, and Talkbox out front on the floor to control. That would be a lot of cables to run back and forth between the GCX and my pedalboard haha. All other effects will be rack mounted on a sliding shelf.

-I actually have no reason to use two Stereo Choruses, as I am wanting both amp rigs to sound the same. However, from my understanding, because the M183’s aren’t true stereo, I do have to use two of them, with the same settings, in order to have two inputs and what would actually be four outputs. If I could somehow save some pedal real estate on my rack shelf, that would be great!

Let me know what you think!

Thanks again!!


Author:  nyteowl [ Wed Jan 10, 2018 6:04 am ]
Post subject:  Re: GCX Worksheet Help

Hi Kyler,

Glad to hear this helped you out, and you can definitely save some real estate on your rack shelf by keeping the Tuner, Wah, and Talk Box out front. There really is no need to put them in loops, and it's always nice to have a few extra loops available if you decide to change your rig in the future, which for a guitarist is practically inevitable. :lol:

As for dealing with lots of cables, check out this site: PedalSnake.com.

And you can save even more rack shelf real estate by eliminating the M183 in Loop 8 entirely, freeing that loop up for another stereo effect you may want to add in the future. The M183 in Loop 7 will be returning a Left and Right stereo signal that will pass thru Loop 8 to feed your Left and Right EVH heads. However, if you want
"...both amp rigs to sound the same..." you'd actually need to feed the same Mono chorus signal to both amps.

Look at it this way: If you put your DD7 in Loop 8 you could bounce a Stereo Ping-Pong type delay effect between the two rigs, which might be something to consider since you can snag a used DD3 cheap enough to use up front. Same deal with a stereo chorus; you'd get a left and right "swirly" effect, unless that's not what your looking for, and if it isn't there's really not much point in using a stereo chorus.

Hopefully that will clear things up somewhat, but if I'm still confused let me know. In any event, do keep us posted on your progress.


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