Quick questions about matching pre- and power amp sections

[waltschwarzkopf]

Hello, World!

I read once that one can use the pre amp section of one amp with the power section of another just by connecting the FX loop out to the FX loops in on both amps.

Is this true?

If so, I would like to see how some of my amps sounds on others. So I have a few questions:

1. Do I need to mind the power? i.e. if one amp is 50W and the other is 15W. Will this be a problem? I guess not because the pre-amp produces a line level signal and the actual power comes from the power section.

2. Do I need to match tube and SS power sections? i.e. I take the pre-amp out of a tube amp and connect it to the power section of a SS amp for lower volume. I guess not, because this is how the valve-state works.

3. Do I need to mind the impedance? i.e. one amp runs at 8Ohms and the other at 16Ohm. I guess not, because this is defined in the power section, and not before.

4. Do I need to use an instrument cable? A speaker cable? Or a custom cable? I guess since the FX loop is connected to pedals through normal guitar cables, this would be enough.

I just need to check with you before I try something wrong and mess up two amps at the same time…

The craziest I would do is to take the pre-section of an amp I like (JTM 30, 2x10) take it to the power section of a smaller amp (Gig Master 15, 1x10) which has an built in power soak, and the connect it to the Vintage 30 speaker (Thunder 50, 1x12) for a fuller sound. Would this work?

Thanks a lot in advance!

Cheers,
Walt


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[jeremy]

you can run the preamp section of one amp (fx loop out) to the power amp of another amp (fx loop in) and it should work as long as the loop levels are similar. if its a tube amp, make sure there is a speaker connected even if you are just running the preamp out. some amps wont carry signal if the series loop is interrupted so you should be able to do what you want in that case, but you should still have a load on the power section or at least i would. if the loop is interrupted (ie you are running out of the loop but not back in) there shouldnt be any signal going to the power section. if its a parallel loop then youll probably run into issues of sound going to the power section. the jtm30 loop is series as far as i remember.

you dont need to worry about any of those things you mentioned and yes, an instrument cable is what you should use. give it a try and see what happens, shouldnt hurt anything

[waltschwarzkopf]

you can run the preamp section of one amp (fx loop out) to the power amp of another amp (fx loop in) and it should work as long as the loop levels are similar. if its a tube amp, make sure there is a speaker connected even if you are just running the preamp out. some amps wont carry signal if the series loop is interrupted so you should be able to do what you want in that case, but you should still have a load on the power section or at least i would. if the loop is interrupted (ie you are running out of the loop but not back in) there shouldnt be any signal going to the power section. if its a parallel loop then youll probably run into issues of sound going to the power section. the jtm30 loop is series as far as i remember.

you dont need to worry about any of those things you mentioned and yes, an instrument cable is what you should use. give it a try and see what happens, shouldnt hurt anything

Excellent! Thanks a lot for the help.


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[NegativeEase]

You should be fine to run Loop Out (send) into any other amp Loop IN (Return) regardless of the power amp size. -you can even run Loop out into the preamp section of another amp if it has a alot of headroom to handle it nicely -if not it will just sound like a distorted mess but no harm done.