Using two amps - stereo or layer - your opinion?

Q & A for building and interfacing your rack gear with Ground Control Pro and GCX-based systems.
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dawesy1986
Posts: 72
Joined: Wed Aug 12, 2009 8:26 am
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Using two amps - stereo or layer - your opinion?

Post by dawesy1986 »

Hey all,
I'm looking into a setup I think I'd like for the future and would appreciate your opinions.

I'd like to feed two amp signals into my System Mix Plus --- that's two amplifiers or two preamps plus a stereo poweramp. I already use stereo Delays and such, but only with one preamp.

When using two amps simultaneously what is generally considered tonally the best thing to do?
A: Send one amp to the left and one amp to the right?
B: Blending both amps into both channels?

Scenario A: If you took an ENGL and a Marshall, you'd sound completely different depending on what side of the room you were..
Scenario B: If you layer them together, you'd be consistent from side to side of the room -- but the only "stereo" element to your sound would be panning (via System Mix Plus) and stereo delays etc

This is not imperative info yet, as I'm still saving, and I guess it IS a personal taste issue so I'll more than likely just have to decide when I get to hear all the gear I want together.. but I want to get a rough idea from more experienced guys out there ahead of time just so I know what pros and cons I may encounter with the different setups.. This could also help me with planning the layout further, thus realising what other things are or aren't possible :)

Thanks guys,
Dawesy.

gerax
Posts: 35
Joined: Thu Jan 27, 2011 10:45 am

Re: Using two amps - stereo or layer - your opinion?

Post by gerax »

Hi

I'm doing a similar thing with my setup.

I have a Mesa Triaxis, a Mesa DC3 combo (now converted to short head for rackmount purposes) and I'm looking around to find a suitable second amp to complete the stereo setup.

My concept is that any amp with an FX loop is actually a preamp and a power amp. So, using a GCX switcher I hook each preamp (the Triaxis is already built for that purpose) input and FX send to the switching matrix; this allows me to choose which preamp to use, so that I can have as much as 6 different sounds (the combos are multichannel, and the Triaxis has lots of sounds) then, at the end of the last GCX loop (I also have some pedals that gon in front of the amps like overdrives and cmpression) I send the mono signal to a SM+ stereo line mixer to have time domain/modulation effects added in parallel (Lexicon and Eventide FX processors) and finally, the stereo mixer's output goes back to both amps FX return, L to amp 1 and R to amp 2 so that I have them as a stereo power amp. From there it's off to the speaker cabinets.

To me, as much as it may seem complicated, it was a simple and convenient solution and it gives me the best of using amp heads, digital and stomp FX and have a wide stereo sound.

Now, there could be the choice of using 2 similar or identical amps for L and R or use two radically different ones. I'm trying to stay with similar ones as you correctly pointed out I don't want my L/R to sound too different from each other, so I'm sticking with the same kind of power tubes section and wattage to keep it as consistent as possible.

Hope this helps

dawesy1986
Posts: 72
Joined: Wed Aug 12, 2009 8:26 am
Contact:

Re: Using two amps - stereo or layer - your opinion?

Post by dawesy1986 »

Thanks for the reply mate, i appreciate it!
Interesting setup too, i think i'm going to have to write that down to map it out as i'm having trouble keeping up with where everything's being routed!

One thing i can tell you straight away is that if you've got one GCX loop to control your amps' Send, then using a second loop to control your amps' Input, the Input loop is redundant -- you only need to control the output of the preamps to mute them, don't need to mute their inputs at the same time as they're silenced anyway.. So you'd just need something like Voodoo Lab's Amp Selector (always switched on) to feed each amp input, then simply mute the output/s of the amp/s you don't want to hear :)

I'm assuming you're using the preamp section of the DC3 and not simply using it's return to act as a power amp, so with that in mind, are you A/B/C'ing between the three amps or blending them?
Are you sending all to only the left of the SM+ or to the right AND left? (and in either case, what are you doing with that third preamp tone?)

I'd have the worst anxiety if ever I had to be your guitar tech; "here you built it -- YOU fix it" haha

:P How's everything wired in this mammoth setup mate?
Dawesy

gerax
Posts: 35
Joined: Thu Jan 27, 2011 10:45 am

Re: Using two amps - stereo or layer - your opinion?

Post by gerax »

Hi

I didn't explain myself clearly, as I'm doing exactly wht you say: I have the send to the preamp from the buffered out on the GCX split to Y to the amp inputs and I use a single GCX's loop to select the return. I put the Triaxis on a separate loop since I didn't want to triple split the signal at the front: as much as a buffered signal could eventually take it without degradation I'm not too confident. I may get something like an amp selector or a Lehle ABC MIDI box down the road to streamline things but for the moment it's like this.
Yes, I'm using the DC3 preamp as well and I programmed a few patches on the Triaxis so that it's muted but its 4 ctrl relays can actually switch channels and EQ in out on the amp head. Works nice and very handy. The idea as you correctly pointed put is to ABC among the 3 preamp sections for any given patch.
Since the signal chain up to the last GCX loop is mono I hit the VCA control on the SM+ in mono and then passive split from Mix 1 In 1 to the 2 FX send. From there I go stereo all the line down to the FX return and power section.
One thing I actually designed (on paper, or power point if you prefer ;-) ) is to have 4 of the GCX loops modified to stereo, so that I will be able to use a Loop Station or Boomerang looper and a Strymon Lex Rotary pedal in the last 2 of them and have it receive the SM+ signal (with FX) before going to the power amp, and switch it out when not used. It may look a bit complicated (and in fact it's quite involved), but once you write it down it becomes quite clear, I suggest you do the same with your rig to keep track of the signal flow.

Wiring...? well...I'm trying to keep it as consistent as possible with all power on the left side (looking at the back of the rack) audio on the right and MIDI/ctrl where it is possible to fit it. I'm hand wiring and custom building all the cables myself with Klotz cable and Neutrik plugs, and so far it's taking lots of time (in my spare time).
Case is 16 RU (2 amp heads, Triaxis, Furman conditioner, GCX, SM+, pedal shelf, dbx compressor, Eventide Eclipse, Lexicon MPX1), quite heavy as you may guess, but it's on wheels and I don't gig that much right now...
I hope I'll be ready to show some pics soon...

Cheers

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