Controlling Dual Rectifier and Mark V with GCX

[barryswanson]

I've posted about this before in the past and I now have A Voodoo lab GCX and Ground Control Pro in my possession. I want to run both my amps in stereo and switch the channels in tandem. I asked on the Voodoo lab forum how I would do this and was told to use a Y cable from both amps to the GCX. Here is the link http://www.voodoolab.com/forum/viewtopic.php?f=9&t=5613

I'm hoping authorised boogie and can chyme in here because I thought using a Y cable with the amps running two different voltages for switching I could damage my amps.?

Can anyone please tell me what cables I need to buy and how to set my amps up so one press on a footswith will get both my amps to switch to channel one or channel three etc.?

 

[etepbbb]

Cant you use one channel to switch the Recto and another channel to switch the Mark? Then they'll remain electrically isolated, since your using the ext. jacks and the switching relays inside the GCX. Or did I miss something?

 

[SonVolt]

I have the exact same setup all working properly. Return that Y cable, you'll get ground loop hum. Buy a proper ABY pedal that has a ground lift switch like the Radial ones and split the signal and place it at the very end of your signal chain and split from there into the input of each amps.

If you don't want to buy an ABY pedal then you could use a stereo delay pedal or a Boss tuner pedal - just a pedal that offers 2 outputs to use as your split. That way it's buffered unlike that Y cable. Then you'll need to buy a ground lift plug from Home Depot and plug one of your amps into it before going into the outlet. They're like 79 cents.

 

[barryswanson]

SonVolt we're talking about using the external switching jacks to control both amps using the GCX.

etepbbb, yeah that's how i thought you would do it but when Voodoo lab tells me to use a Y cable I get confused.

 

[etepbbb]

http://www.whyleuwait.com/gear/gcxconfig.jpg
Looking at the , the jacks all have a common sleeve connection, so they are not electrically isolated. This may or may not be a problem, I do know Mesa's can be funny about that kind of stuff. Best to find a different way.

 

[SonVolt]

SonVolt we're talking about using the external switching jacks to control both amps using the GCX.

etepbbb, yeah that's how i thought you would do it but when Voodoo lab tells me to use a Y cable I get confused.

Oh - I thought he was trying to split the signal to both amps AND use the switching jacks to change channels. If he's just wanting to change channels on both amps with the GCX then send a GCX loop OUT or SEND (depending on if it's normally open or normally closed) to each amp's channel switching jacks. That will eat up 4 loops on the GCX - one for channel 2 of each amp and one for channel 3 of each amp. Channel 1 is the default and won't require a GCX loop.

Honestly now that I think about it, I don't see why the Y cable would be a problem if it's going from the GCX to the switching jacks on each amp. That would not the same thing as linking the heads together by their relay jacks which IS a problem.

Do not daisy chain the amps together via the relay jacks - that will work with 2 Rectifiers but not with a Mark V and a Rectifier. I've already asked Boogie and they advised against it.

 

[barryswanson]

The y cable method is the way I'd prefer to go if I could go save loops but without the y cable having a stereo plug at the joining end they will be electrically connected.

 

[SonVolt]

I'm not sure if everyone's aware of this but Voodoo labs has a dedicated relay switcher that's only like $200. With 4 isolated relay controls it can toggle between all 3 channels on your Mark V and Recto in tandem. I would buy one of those and save your GCX loops for effects.

http://www.voodoolab.com/controlswitcher.htm

 

[Authorized Boogie]

1) The following Mesa amps DO NOT use ground as a switching reference, and could be damaged if not connected correctly when using an external switching device:
3 Channel Dual and Triple Rectifiers (non-Multi-Watt)
Series 1 Road King, Serial #s RK 0011 to RK 2146
Series 1 Rectoverb, Serial #s R50 011 to R50 1491
Series 1 Solo 50, Serial #s S50 011 to S50 1675
Nomad 45, 55, 100, ALL Serial #s. Note: Nomads do not have external switching jacks, but this information applies to our breakout box.

These amplifiers use -3V as the switching reference, which is connected to the sleeve of the external switching jacks. This means that the switching reference of any switching device must be isolated. If the switching reference is connected to ground, damage to the switching circuit and the circuit board will occur. This also means that if the switching reference of the switching device is isolated, Y-Cord function switchers can be used, but the Y-Cord cannot be connected to any other device or amplifier.

2) Electra Dyne; Express and Express Plus; Lonestar; Lonestar Special; King Snake; Mark IV; Mark V; Stiletto Ace, Deuce, and Trident; Roadster; Series II Road King; Rectifier Recording Preamp; Rectoverb 25; Series II Rectoverb/Solo 50; Two-Channel Dual and Triple Rectifiers; Three Channel Multi-Watt Dual and Triple Rectifiers; Mini Rectifier; Royal Atlantic; Simul 2:90 Power Amp; Tremoverb; TA15 and TA30; Bass Prodigy; Bass Strategy; Big Block 750, Big Block Titan V12; M6 Carbine and M9 Carbines.
These amplifiers all use ground as the switching reference. This means that Y-Cord function switchers can be used, but if the Y-Cord is connected to any other device, a ground loop may occur.

Also, all amps listed under #2 that use Mono or TRS footswitch jacks can use the footswitch jack for external switching. The switching reference is ground. In most cases Tip is the Channel and Ring is the Solo or Reverb.

 

[SonVolt]

Would a GCX loop be considered "isolated"?

 

[barryswanson]

So have I understood this correctly? If I have a Mark V and new Multi Watt rectifier I'm able to use the y cable method to connect to the GCX?

 

[barryswanson]

Authorised Boogie, if so does the required Y cable need to have mono jacks on all three jacks?

 

[Authorized Boogie]

Yes, you can use the Y-Cable with those amps.

Most Y-Cables are Stereo on the single end, and Mono on each of the Y ends...thats the only way to have a stereo jack control 2 mono functions. Thanks!