Is this rack setup possible?

[Jeff]

I have a smokin' JCM 800 head and a JCM900A cab. Would it be possible for me to have an effects loop installed in the head, and then use the Marshall power amp with like a Triaxis? Like...either I can use the head straight into the cab like I am now, or run through the triaxis, through the power section on the Marshall head and into the cab?

And if so, would the power section clip a lot with clean tones cranked up high?

[Lonely Raven]

Most heads based on a vintage design can be modded for effects loops
and extra gain stages and different tone setups and whatnot. Especially
the Marshalls. For years there has been a market for Marshall mods.

But honestly, if all you want is a good power amp section, look into a
dedicated tube power amp like the stuff from Mesa Boogie, or even
Marshall made (and probably still makes) some.

So yeah, what you are looking for is possible, but unless you like
experimenting yourself and doing work yourself, it's probably going to
be expensive, void all sorts of warranties, and you might not be happy
with what you have.

Try to keep things simple. Most of the best setups are the simplest.

[Mandrak]

IŽd trade it for a Mesa or VHT power-amp.

[BCShredder]

you are defeating the purpose of the triaxis by running it through a marshall head. If you don't like the head then sell it. 800's are great heads though just have it hot roded. If you still want more sounds get a switching system and another preamp or amp. Effects loops are pretty cheap to install.

[Jeff]

I like the Marshall head, I'm just trying to save money here so I don't have to buy a power amp when I could use the one in my JCM 800 (if it's possible) Will it just not sound good at all with a Triaxis or an ADA or any pre amp?

[frankfalbo]

Everything sounds fine except the "power amp clip" statement you made. I use '68 Fender heads as my "rack" power amps. They stay clean because they are from that period when CBS thought distortion was bad So they aren't the best blues overdrive heads when cranked, but with my different tube preamps and such, they are awesome. What I don't know is if the Marshall power section will break up the clean sound at high volumes. I would say that when you're having the loop installed, try to communicate that you want a "clean power" sound. You might want to have a lower gain stage feeding the power amp. Or you could have send and return levels installed. You wouldn't be using the send, but you could limit the return, and as long as you're putting on one knob you might as well put on two! Its possible that the breakup could be affected by where in the signal chain they put the loop, also, like pre or post driver tube. I think my Mesa MKIIB had a jack under the chassis that was a preamp out/power amp in. Not an in AND out, but rather just a tap into that part of the signal path. That would work also.

[syxxstring]

years ago i head a marshall head and a jmp-1 based rack. the best my rack ever souned was using it to push another amp.