Does anyone know a method of putting two amps into one cab?

[mattfode]

Does anyone know a method of putting two amps into one cab?
I have a vintage fender twin and an old 70's orange head which I was foolishy going to sell for floor space, and then lightbulb moment - can't I play that through the fender cab speakers using a switch?
I fly by the seat of my pants electronically, but I have managed to make some pretty decent pedals courtesy of the chaps here - so naturally I thought to ask the tried and tested.
If anyone can help that would be Great.
Thanks in advance.

[Beaker]

The problems you need to be aware of, is that you must have a load (speaker) present on a valve amp at all times, or you can blow your amp, so your switching solution can't just simply "cut" the signal from the amp to the cab.

The other problem is impedance mis-match between the two amps, which can cause damage too.

If your amps have the same impedance output, that makes it easier.

It also depends on your cab. If it's a stereo cab that makes it easier.

EDIT: If it's not a stereo cab you would need to re-wire as stereo, otherwise two signals into one mono speaker cab, and something is going to go bang!

You can use something like this, designed to do exactly what you describe I think:

http://www.tonebone.com/headbone.php

[Beaker]

Actually, that Headbone won't do what you want, as it's an either/or (amp A or amp B) switcher,  not both at the same time - things will go bang otherwise.

The more I think about it, the solution is to use a stereo cab (or re-wire it with an extra jack socket to run in stereo).

That way you can use a AB-Y box between your guitar and the amps.

Output A goes to amp A (Fender) into left hand pair of speakers in your 4x12.
Output B goes to amp B (Orange) into right hand pair of speakers.

That way you can toggle between amp A, amp B or both amps at the same time (each driving two speakers).

Your ABY box will need to be transformer isolated, with a ground lift (to prevent ground loop), and a phase switch to prevent one amp "blowing" while the other one is "sucking".

I can vouch for these - my son has a custom ABC-Y box Bright Onion made for him for running his three amp rig. Handmade in Brighton England. Really nice guy to deal with, and very good build quality for the price.

http://www.brightonion.co.uk/active-aby-pedal-with-isolated-second-output/