Mesa Boogie GCX slave and Axe FX wet/dry rig

Q & A for building and interfacing your rack gear with Ground Control Pro and GCX-based systems.
Manhell
Posts: 83
Joined: Tue May 26, 2009 3:33 pm

Mesa Boogie GCX slave and Axe FX wet/dry rig

Post by Manhell »

Hey there,

So, I'm running my rig with a Mesa/Boogie Road King head as my dry sound and a Axe Fx+ Mesa/Boogie 50/50 as the wet rig.

I have it connected like this; the guitar goes in the Guitar in of the GCX and splits into two, one signal goes to the Road King and the other to the return of the first loop, then a cable comes from the slave out of the Road King to the input of the 1st loop in the GCX and from that loop the out goes to the input of the Axe Fx so I can choose if I want the signal from the Road King or use it as a separate amp.

So my problem and doubt is;

1-will this harm any of the amps in any way
2-will I experience phase problems and what can I do to solve them
3-is this connections viable and well done?


Thanks

nyteowl
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Joined: Mon Jan 25, 2010 8:53 am

Re: Mesa Boogie GCX slave and Axe FX wet/dry rig

Post by nyteowl »

I'm not too sure about those Loop 1 connections, because you're feeding your guitar signal to the Loop 1 Return while the Road King's Slave Out signal - which, per the Mesa manual, is derived from the speaker jack and therefore has already gone through the Mesa's preamp - is going to the Loop 1 Input. I suspect there will be a significant difference in the levels of these two signals and don't think feeding your Axe a signal that has already gone through another amp's preamp section is a very good idea.

I would take the guitar signal from the rear panel Guitar Out and connect it to the Loop 1 In; connect the Loop1 Out to the Road King Input; connect the Loop 1 Send to the Axe Input. Doing this will let you switch between your wet and dry signal.

A second option would be to take the guitar signal from the rear panel Guitar Out and connect it to the Loop 1 In and connect the rear panel Feed Thru to the Loop 2 In. Connect the Loop 1 Send to the Mesa and the Loop 2 Send to the Axe. This will not only let you choose between which of the two amps to use alone, but will also let you run them simultaneously.
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Manhell
Posts: 83
Joined: Tue May 26, 2009 3:33 pm

Re: Mesa Boogie GCX slave and Axe FX wet/dry rig

Post by Manhell »

yes I know that, but I do not want that connection, when I use the slave out into the axe fx, the axe fx is for effects only, when I switch it to the guitar signal then it's two separate amps,

I wanted to have the Road king signal most of the times running the axe fx and the power amp and for one or two songs the axe fx as a separate pre and power amps

nyteowl
Posts: 1389
Joined: Mon Jan 25, 2010 8:53 am

Re: Mesa Boogie GCX slave and Axe FX wet/dry rig

Post by nyteowl »

I understand what you're trying to accomplish, but running an already pre-amplified signal into the input of your Axe as you intend to do is definitely not a good idea, unless part of your plan includes potentially damaging your gear and/or voiding your warranties.

In my experience, Fractal offers the most comprehensive manuals I have ever encountered, and the diagrams on Pages 17 and 23 in the Axe FX Manual show the proper way to use an Axe as an "effects processor only" with a guitar amp, using the Out2/In2 jacks on the Axe's rear panel.

For Sale: Original DMC GCX in Excellent Condition ($275) and a far more versatile SoundSculpture GL also in Excellent Condition ($1750). Free CONUS Shipping.

Manhell
Posts: 83
Joined: Tue May 26, 2009 3:33 pm

Re: Mesa Boogie GCX slave and Axe FX wet/dry rig

Post by Manhell »

I see and I know that, but the Mesa manual says that you use the slave out to connect another power amp and run outboard effects, the Axe Fx is a preamp but also a effects unit that can be used only for effects, If I had a G major I could do the same with the slave out and I think that using the slave out it's better the using the effects loop out and then split the signal in two in the axe fx.

actually I don't see how running this setup, even without GCX, could possibly damage the Axe Fx. I quote the manual;

"This 1/4” jack and control provide a signal derived from the speaker jack. Perfect for using either the Road King head version or combo as a master pre-amp and additional power amps for more power when needed. Some players use the SLAVE to derive an FX
Send Signal and go to other amps for their wet sound."

So I don't see a problem here.

nyteowl
Posts: 1389
Joined: Mon Jan 25, 2010 8:53 am

Re: Mesa Boogie GCX slave and Axe FX wet/dry rig

Post by nyteowl »

Okay, so now you don't see a problem, but you did write this in your original post...

"So my problem and doubt is;

1-will this harm any of the amps in any way
2-will I experience phase problems and what can I do to solve them
3-is this connections viable and well done?
"

...and while none of those questions have anything to do with Voodoo Lab products the answers, IMHO, are:

1-Yes, you may well damage one or both of your amps.
2-Irrelevant (see answers 1 and 3)
3-No, those connections are not viable, nor recommended.

Regarding the use of a G-Major, the reason you can send the Mesa's Slave Out signal to a G-Major is because the G-Major is an effects unit ONLY and not a preamp, whereas routing the Mesa's Slave Out to the Axe FX Input will route your signal out of one preamp directly into a second preamp.

I am not saying an Axe cannot be used as a stand-alone FX unit, but there is a preferred way to go about doing that. All things considered, I would place far more confidence in the Fractal instructions for making those connections than I would in a single sentence reference in the Mesa manual about what other players may or may not be doing with their Road King.

I've been wrong before and perhaps I'm wrong about this, too, but I am simply trying to make you aware of the potential damage you could do to your Axe by stacking preamps. I own an Axe FX II myself, and one thing I do know for sure is, I would never make the connections as you described when the exact same result can be accomplished by following directions provided in the Axe FX manual as well as on the Fractal Forum.
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Manhell
Posts: 83
Joined: Tue May 26, 2009 3:33 pm

Re: Mesa Boogie GCX slave and Axe FX wet/dry rig

Post by Manhell »

Ok let me expose my thought on the matter so we can discuss this, because what I want is to do safe connections with my gear so I take seriously what I read.

1st, the phase problem is for when I use the Axe Fx and 50/50 as a separate rig from the Road King, like A/B/Y each in is own speaker cab.

2nd, I see what you say with the feeding a preamp with another preamp but if you do not use the AMP block in the grid, you'll not be using a preamp or amp at all, if that was the case I couldn't connect the Axe Fx to a external power amp or a speaker cab, now that it is not recommended to use it as a preamp feed another preamp or use the SPEAKER block when using external cabinets.

So I assume it's almost the same so if I do not use the AMP block it will be an Effects unit only.

nyteowl
Posts: 1389
Joined: Mon Jan 25, 2010 8:53 am

Re: Mesa Boogie GCX slave and Axe FX wet/dry rig

Post by nyteowl »

1st, all of your issues revolve around the interaction between your Road King and your Axe FX, up to and including how to properly make your Axe FX connections.

2nd, and I mean absolutely no offense by this, since this is the Voodoo Lab forum and you're not asking any Voodoo Lab related questions, I respectfully suggest you pose your questions on the Fractal Audio forum, where people who possess far more Axe-FX knowledge than I can answer all of your Axe-related questions.
For Sale: Original DMC GCX in Excellent Condition ($275) and a far more versatile SoundSculpture GL also in Excellent Condition ($1750). Free CONUS Shipping.

Manhell
Posts: 83
Joined: Tue May 26, 2009 3:33 pm

Re: Mesa Boogie GCX slave and Axe FX wet/dry rig

Post by Manhell »

Non taken,

I came to ask about my connections that have the Voodoo lab GCX at heart, and I wanted to know first of all if the GCX could have phase inversion problems when splitting the signal and if the slave out is a signal that can be routed through the GCX, that were my main questions,

I've also exposed the issue in the fractal forum and people that answer said that they're using a similar setup and will not harm the Axe Fx.

Manhell
Posts: 83
Joined: Tue May 26, 2009 3:33 pm

Re: Mesa Boogie GCX slave and Axe FX wet/dry rig

Post by Manhell »

one more thing but out of pure curiosity; are you related with voodoo lab in any way like one of the builders, or researchers or work at voodoo lab?
I am asking this because you usually answer a lot of people's questions and have your text in blue, so I am wondering this for a long time.

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