2 Preamps, FX Loop, 2 Poweramps

[TKVienna]

Hi Community,

I am new to the board and the GCX world and have some questions. Thanks in advance for your time!

I have recently added a new pre-amp and a new poweramp as well as a GCX Switcher + GCP to my rack. The rack now consists of the following:

Self-Designed/Made Mono Poweramp (100W)
Mesa/Boogie 2:100 (new)
JMP-1
Triaxis (new)
Boss SX 700 (Studio Multi Effects Unit)
Rocktron Pro-Q (EQ/Hush)
GCX Switcher + GCP (new)
Behringer Racktuner

I have split these into a rack of 6 units, which hosts the power amps, and a rack of 10 units, where the preamps, GXC and effects/pro q are.

Going forward, I want to add a few effects to my rack, which will go into a drawer placed in the 10 units rack. I am currently thinking of getting a Phase 90, Whammy Board, Fuzz and a tremolo/chorus/delay-effect (maybe a MemoryMan; don't know yet).

Reason for bothering you is that I want to be able to select either the JMP-1 or the Triaxis as preamp and run them into the 2:100 or my selfmade poweramp. And I want the effects (except for the fuzz) to run into the FX loops of the Triaxis and the Mesa Boogie.

After some thinking and research, I came to the conclusion that it will likely not work to use the FX loops of the preamps for the effects at the same time and be able to switch between them UNLESS (i) you mix the signals or (ii) use two GCX loops to switch between the pre-amps, which I would like to aviod.

So I will likely use the GCX loops as follows:

Guitar Signal -> Guitar In
Feed thru -> Tuner (STOP)
Guitar Out - > Loop 1 in
Loop 1 -> Fuzz -> into the preamps (via the Loop 1 Out, using an Y-cable)
JMP-1 Out -> Loop 2 in / Triaxis Out -> Loop 2 Return
the other loops are used for the effects
Loop 3 -> Pro Q
Loop 4 -> Whammy
Loop 5 -> Phase 90
Loop 6 -> MemoryMan?
Loop 7 -> Boss SX 700
The last loop is used to switch between the Power Amps:
Loop 8 -> Amp 1 (Send) or Amp 2 (Out)

I would be interested in your thoughts / comments / recommendations, in particular if you have any idea of how to use the effects in the FX loops of the preamps (without mixing the signal). I am also not 100% sure if it is really necessary to use the FX loops of the preamps as I will then always have the issue that the output of the wet/dry signal will not be levelled (same volume).

Again, many thanks in advance.

Best regards,
Thomas

[nyteowl]

It's no bother at all, just a bit of a challenge to figure out the optimal way to make all these connections. This...

Loop 1 -> Fuzz -> into the preamps (via the Loop 1 Out, using an Y-cable)
JMP-1 Out -> Loop 2 in / Triaxis Out -> Loop 2 Return

...indicates that you will be using one pre-amp or the other, because as outlined above you will not be able to use them together. I'm also guessing, because you're returning both preamp signals to the GCX, that your intent is to "hardwire" your effects between the pre-amps and power amps.

You're also using a pair of stereo pre-amps with both a stereo and a mono power amp, so do I understand correctly that you'll be running everything in Mono and you want to not only switch between pre-amps but also select which power amp to use with whichever pre-amp you've selected? Also, while I'm trying to get a handle on your rig, could you please explain why you want to use two different power amps? What is the advantage to doing that, and where does the signal go from the power amps? How many cabinets are you using?

Normally I would recommend using 1 GCX loop for switching preamps and 2 GCX loops for the pre-amp FX Send/Returns, which is perfectly doable with what you have now, as your Fuzz will occupy 1 loop, and the SX-700 and Pro-Q will each occupy a loop for a total of six loops leaving 2 open. Unfortunately, if you plan to add more than 2 effects pedals you'll need more loops. In any event, I'll wait on your answers to my questions before making any suggestions.

[TKVienna]

Hi,

thanks alot for your swift reply.

1. Yes, I intend to use one pre-amp or another.
2. What do you mean by "hardwire" my effects?
3. It's fine to run everything in mono.
4. There is no particular reason for using different power amps. I have two and I want to switch between these. I may eventually skip this option, which should free up one loop.
5. The power amps will go into a 2x12 cabinet for the time being

I hope this answers your questions. MANY THANKS.

Thomas

[nyteowl]

1. Switching between pre-amps is not a problem, but I would go about doing it a different way.

2. By "hardwire" I meant you would be putting your effects directly in line between the pre-amps and power amps, as opposed to running them in the pre-amp FX Loops.

3. Mono, no problemo.

4. If there is no advantage to using two power amps, why go to all that trouble? See response 5 below.

5. Is that 2x12 cabinet a stereo cabinet? One cannot use a GCX to feed two independent power amp signals into a single mono cabinet without running the risk of doing serious damage to your both your GCX and your power amps. You need a device especially made for the purpose of switching between two power amps so one amp's signal is sent to the cabinet while the "idle" amp sees a dummy speaker load, something along the lines of the Radial Headbone or the Palmer E-Frog.

[TKVienna]

Thanks.

1. I would be interested learning which way you would go!

2. I would actually prefer to run the effects through the FX loops as this allows me better control of the output volume (I believe), but I dont know how to wire the loops to avoid mixing the signal from both preamps and the effects.

3. Good.

4. Say it this way, I have an empotional preference to use both poweramps.

5. Thanks, that's clear. The cabinet is a stereo cabinet, so I can use it with both poweramps. Also many thanks for the links to the devices - that was what I was looking for!

Thomas

[nyteowl]

Revisiting 4 and 5, if you want to run both power amps, that's your prerogative. It can be done, but you'll have to run each amp into its own speaker cabinet "channel" so whichever amp is "idle" will still see a speaker load. That means only one speaker will be live at any given point in time. Are you okay with that, or will you be adding a Headbone or E-Frog to your rig to handle the amp switching?

In any event, I think I can get you up and running with just your GCX and the effects you have now going through the FX loops, but if you plan to add more pedals later, i.e. "...a Phase 90, Whammy Board, Fuzz and a tremolo/chorus/delay-effect (maybe a MemoryMan...)", you'll need to add more loops to handle them, in the form of either a Pedal Switcher or another GCX.

[TKVienna]

I am okay that only one speaker will be live at the moment. I may add an amp switcher later.

How would you wire the preams and effects that I have now so I can use the effects in the FX loops of both preamps without mixing the signals?

Thanks.
Thomas

[nyteowl]

If this were my rig, I would use the Triaxis as my default preamp, but if you'd prefer the Marshall as the default just swap out their respective locations and make the connections as follows:

Guitar -> GCX Front panel Guitar In
GCX Rear Panel Guitar Out -> Loop 1 In
Loop 1 Send/Return -> Fuzz In/Out
Loop 1 Out -> Loop 2 In
Loop 2 Send -> JMP-1 Guitar In
Loop 2 Return: Not Used
Loop 2 Out -> Triaxis

This eliminates the Y-cable, yet still puts the Fuzz in front of both pre-amps and allows you to use select the active pre-amp using Loop 2. Moving right along...

Triaxis FX Send -> Loop 3 In
Loop 3 Send: Not Used
JMP-1 FX Send -> Loop 3 Return
Loop 3 Out -> Loop 4 In
Loop 4 Send/Return - Pro-Q In/Out
Loop 4 Out -> Loop 5 In
Loop 5 Send/Return -> SX-700 In/Out
Loop 5 Out -> Loop 6 In
Loop 6 Send -> JMP-1 FX Return
Loop 6 Return: Not Used
Loop 6 Out -> Triaxis FX Return

Now it's imperative that, when programming your presets, Loops 2, 3, and 6 are always in the same state, either all Active (On) or all Inactive (Off) so that when you switch pre-amps you will route the effects thru the proper pre-amp's FX Loop.

Here comes the part where you and I would do different things. Me, I would forget about using two power amps, because there is absolutely no advantage in doing so and it would needlessly complicate things, not to mention waste two GCX Loops that could be put to better use. I would simply run the Triaxis and JMP-1 Mono outputs to the left and right channels of the Mesa Power amp, then connect the power amp to the cabinet and be done. However, if you really want use both power amps and switch between them you could do this:

Triaxis Mono Out -> Loop 7 In
Loop 7 Send: Not Used
JMP-1 Mono Out -> Loop 7 Return
Loop 7 Out -> Loop 8 In

Loop 8 Send -> Power Amp 1
Loop 8 Return: Not Used
Loop 8 Out -> Power Amp 2

Now in addition to ensuring Loops 2, 3 and 6 are always in the same state, you'll also need to include Loop 7 in that group as well to ensure the selected pre-amps output is going to a power amp, and you'll use Loop 8 to choose the active power amp.

Good luck and let us know how you make out.

[TKVienna]

Thanks alot, that was very helpful! Using an Y-cable may save me one loop, right? If I use a proper cable, do you see a quality issue?

Is there a way to link the loops for the preamps together so that I just have to hit only one button (other than programming a preset, which would work fine of course)?

I let you know how I ended up (and will post some pictures).

Thanks so much for your help.

Thomas

[nyteowl]

If you use a Y-cable, how will you control the fuzz if it's not in a loop?