Mixing Preamps into one power amp?

[ibanez4life SZ!]

Hey guys!

I love the overall tone of my Roadster, but REALLY like the midrange bark found in the Mark series. I also like how they come together when running the amps together.

Hoping to keep things simple, and avoid running two power amps (I don't use stereo effects), I got an idea today

If I purchased a preamp such as the Mesa Studio Pre, or Triaxis, would it be possible to use a unit such as the Suhr Mini Mix (this unit has the switching features I like for more versatility), or RJM Line Mixer, to blend the additional preamp with the the preamp of my Roadster? The mixed down signal would then go into the return of the amp, and run out the single power amp.

Has anyone tried this approach? Does it impart the characteristics of each preamp, or will it just work more like a different EQing, since I'm just running one power amp?

What problems should I look out for? I assume phase is still an issue? Anything else?

Appreciate your input!

Eric

 

[petejt]

I suppose you could mix them in that way.


But personally I think it would be easier to just run them in stereo. Split your signal to both preamp inputs, and have the Roadster's preamp output to the left channel input of a stereo poweramp, then the other preamp output to the right channel input of the stereo poweramp.

 

[ibanez4life SZ!]

I was thinking about that, but I'm trying to get this done as logically as possible...that method would leave the Roadster power amp unnecessary, and it would still require a load.

Eric

 

[RACKSYSTEMS]

Yeah you can do that but there will be phase issues. If you have a switcher you can put a phase reverse transformer in a loop after one preamp and switch it in when its out of phase.

 

[moltenmetalburn]

Hey dave can you answer the OP's other question also please I too would like to know.

"Does it impart the characteristics of each preamp?"

 

[ibanez4life SZ!]

That's what I'd like to know aswell

 

[Sixtonoize]

Has anyone tried this approach? Does it impart the characteristics of each preamp, or will it just work more like a different EQing, since I'm just running one power amp?

I used to run a bass rig this way. It definitely adds the characteristics of the two preamps together.
It doesn't sound as huge as using two separate amps (after all, you've only got one power section and one set of speakers), but it will sound more harmonically dense than just using one.

As long as your preamps are in phase and you've taken care of ground loops, you're good to go.

 

[ibanez4life SZ!]

One last question...

Is there any easy way to test the phase of a signal? When two amps each have their own speakers, I guess I can just see which way the speakers are kicking, but what about in this situation? What do I need to do it with these preamp signals that are being mixed down?

I guess I'm also curious if this "preamp mix-down" really gets close enough to the sound of running two amps for a blended tone, or it I should just stick with the two amps separately? Anyone go through this situation?

Eric

 

[Sixtonoize]

One last question...

Is there any easy way to test the phase of a signal? When two amps each have their own speakers, I guess I can just see which way the speakers are kicking, but what about in this situation? What do I need to do it with these preamp signals that are being mixed down?

If the preamps sound like shit when you mix them, but fine on their own, then they are out of phase.
When you have two signals that are out of phase, they will add destructively - they will get quieter when you combine them. The most extreme case is two identical signals...when they're added together, they will cancel completely and there will be no sound at all.

I guess I'm also curious if this "preamp mix-down" really gets close enough to the sound of running two amps for a blended tone, or it I should just stick with the two amps separately? Anyone go through this situation?

That's totally up to you, and the only way to really know is to try it.
I thought my two-preamp rig sounded amazing and was WAY easier to carry than two amps.
However, using a single power section and a single cab till never sound like two separate power sections - that's just physics.