Multiple RM4 Rig Help Needed

[guitarcollection]

I am in the process of building a new rig with (3) RM4's. So far I have the following...

Axess FX-1 Footcontroller
(3) Randall RM4's w/ (Brown Pete Mod, XTC Pete Mod, Tweed, Mr. Scary, Grail, Super V, 1086, SL+). 3rd one is empty for the pending KH modules and other NAmm surprises)
(2) GCX Switchers
(1) Digitech GSP1101
(7-8) Pedals that I will switch in and out of GCX loops
(1) VHT 2/90/2 Power Amp

Essentially, I want to feed my guitar's wireless into the Digitech GSP1101 and then feed 4 different ((3) midi switched Roland RM4's and a Roland JC-120 into the GSP1101's preamp loop. As of right now, the GCX's will be used only to switch pre-amp pedals (phaser, tube driver, etc.) in and out before they hit the Digitech unit. The reason I want to feed the preamps into the preamp loop of the digitech unit is so that I can not only use any of the 4 preamps with the internal effects, but also bypass them and use the internal preamp within the GSP1101. My question is what will be required to switch between the 3-4 preamp choices. I was considering using a Axess GRX4, but Mario from Axess got back to me and said "The GRX4 doesn't have the necessary transformer isolation to prevent Ground Loop Hum and Noise that will occur as soon as you connect up the four preamps". Anyone switching between (3) RM4's?

 

[SacredGroove]

Is the ground loop/hum issue your question or is it how to cable up all the preamps through the 1101 or both?

Scott

 

[RD/Rich]

Check out the Sound Sculpture Switchblade. It?s like the GRX and GCX on steroids. I think that it will do the pre amp switching you need to do and isolate the grounds so that loops are not a problem.

http://www.soundsculpture.com/products/switchblade.htm

You also might want to check out HRI. A lot of the guys over there have some pretty killer rigs and they can also point you in the right direction.

http://www.hugeracksinc.com/forum/portal.php

 

[guitarcollection]

My intial question was how do I do it? Mario pointed out the potential for the ground-loop problems, so I guess both questions now....

 

[c2ply]

The switchblade will work great but is a really expensive piece. Prior to getting into the mod system I used to use a huge rack (21 space shock rack with gear mounted in the front and back) and used to use 3 preamps (a soldano, marshall, and an ada), I used a Mesa High Gain amp switcher - it isolated each preamp so no ground loops, its basically a 4 way loop with one in and one out. It uses 4 1/4in ts jacks to turn the preamps on or off - so you will need to use 4 loops from one of the GCX's - but the great thing about it is you can combine multiple pre's/amps with it. My old killer sound was a soldano X88 crunch channel with a lighter gain JMP-1 patch. You can sometimes find the Mesa High gain amp switchers for sale on ebay and others, and I think mesa still makes them, but they are custom order only - not sure though as when I got the randall stuff I sold almost all of the old rack. So with it you would talk the loop send from the GSP1101 to the in of the High gain switcher, the out of the switcher would be the loop return of the GSP. Then each pre/amp would be in the high gain switchers loops, and plug 4 switching jacks into the High gain switcher and your done.

 

[guitarcollection]

c2ply,

Thanks for the great insight. That sounds like exactly what I need... none on ebay at the moment. I got a call into Mesa already..... hopefully if that doesn't pan out someone else makes something similar.

Best Regards,

Marc in Philly

 

[c2ply]

Actually there is one on ebay now (not mine)

http://cgi.ebay.com/MESA-BOOGIE-AMP-SWITCHER-NO-RESERVE_W0QQitemZ250182511322QQihZ015QQcategoryZ43374QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Item #250182511322

I think I sold mine for around $350 about a year and a half ago.

 

[fatang]

See if you can find an old Mesa Boogie Amp Switcher.

http://guitargeek.com/gearview/288/

Robert

 

[jimosity]

I am using a somewhat similar setup; in terms of using multiple preamps...
What I'm doing is this:

I'm running out of my wireless into my Digitech GSP1101, then out of it, into my Axess Electronics BS2, then into a GRX4 <I know the GRX4 has a buffer in it and the BS2 is essentially overkill, but it's still a nice unit to have>.
I then run each loop out of the GRX4 to the input of four different preamps, then the outputs of each preamp back to the GRX4 return of that particular loop. Then I have the main output of the GRX4 being sent to my power amp.
That way I can have essentially five (four from the GRX4, plus the internal preamp section of the GSP1101) preamps to choose from.

That's the simple version of what I use, but I'm actually using two GRX4's (one for preamps, one for effects units) and then I've got my main out of the last GRX4 going to another effects unit (mainly for use with spillover delays and a final noise gate before hitting the power amp).

I used to use the GCX, but the GRX4's are much nicer for this application and require far less cables to make it all work. I'd keep the GCX for putting pedals and odd things into the mix and get a GRX4 to switch between preamps.

 

[Lonerock]

You'll need a kind of BS2 buffer to feed preamps inputs with isolated outs to avoids ground loops and keep one of your GCX for switching between preamps outs, as GCX loops are not isolated from the others, you must not use pre gain loops (egd or dist pedals) and post loops in the same GCX.

That's why the GRX4 are cool cause loops 1/2/3 are totally physically isolated from loop 4.

 

[guitarcollection]

Thanks everyone for the great insight. Based on c2ply's intial recommendation, I've just bought a Mesa Switcher.... Ironically, I was looking back through some photos from an old Japan Guitar mag that had a feature on Metallica's guitar rigs from the reload tour and Jaymz was using that piece to switch between (2) Tri-Axis premaps and a Roland JC-120 head. I never noticed it in his rack before or I must of thought it was something custom, but there it was... I'll let you know how I make out once I get things set-up.

 

[RD/Rich]

Dude, we need to see some pics of this beast!!!!!