Setup multiple heads into one cab...

Hey...ok, now I want to setup 2 marshall heads into one marshall jcm900 4x12 cab, in a safe manner that won't damage anything (haha, I'm known for damaging stuff!). I want to be able to footswitch between them too, kind of like using each amp as a seperate channel. This must be possiable, how would I go about doing this? Hopefully a rather inexspensive way...hope you guys can help me out, thanks in advance! -Matt

I've heard of using two cabs, but not two heads. With two cabs, you can just buy an A/B switch. This is what I'm doing and it seems to work good with no problems.

Hmmm...yea, I'm familiar with what you mean...now, Zakk Wylde, though not very much of a fan of him, I believe he runs two marshall jcm800's (50 watters) into one cab...this is where I kind of got the impression that it was possiable I guess. Now whether or not he switches between the heads i don't know, I figure he probably doesn't. Umm, oh well, if anyone has any ideas that'd be cool...I think it can be done through midi routing setups, but i rather just go buy another Marshall 4x12 if we're talking a solid chunk of money to make the switchable two-heads-into-one-cab setup possiable...Thanks -Matt

the only thing I can think of would be to change the cabinet's jack so instead of all it's options, the 2 jack spots would be wired identicle so you could run either or. I'm not sure, but you would probably have to rig something to keep both channels from being able to run at the same time (not sure how that would affect the ohm's). Besides that you could get 2-2x12 cabinets, but you just can't beet a Marshall 1960A cab. I know, I've got one too.

OK, when you are playing through one head, the other one has to be kept happy...

That means you have to supply a load to the output that matches the O/P transformer, and you should do something to make sure that the input has no signal applied to it. So you need a special kind of A/B switch that can direct your guitar signal to the right input, and also connect the selected amp to the speaker cabinet, as well as making sure that the unused amp stays healthy. This ain't a good time to be "learnin' on the job"!

Find a good amp tech and explain what you want to do. This isn't rocket science, but it will require some fancy switch gear.

hey hey guys, thanks for writing in, I definitely appreciate all the input...I guess me being cheap and all, haha, I was hoping there would be an easy solution for setting up both marshalls into my JCM900 4x12. But really, I wanted to use the same cab because the one I'm running now is amazing. I put some vintage greenbacks in it, the 25watters, doesn't sound like any cab I've owned! But oh well, is there ever an easy solution?? haha! It's good that you brought up the dummy load concept there, I knew that but for some reason it didn't even cross my mind until you mentioned it. So now putting some of the pieces together, this is a little more involved than I imagined it being. Well, looks like another marshall 4x12 for me boys, haha! It gives me a good excuse to buy another one anyways, can never have enough marshalls around, that's for sure! I think my beat-up plexi deserves a nice old beat-up cab anyhow, haha, give it some character! Thanks again guys, keep rackin' dudes!