Two amp heads, 1 Cab

[keithus77]

I have heard to run to seperate amp heads through one quad box you need an amp switcher of some kind (ie Radial Switchbone).

Is it possible to run two amp heads into the same stereo quad with the guitar hooked up to an AB pedal in front to switch between the amps?

This is quite possible practically, but I would like to know if I do this will I damage anything?

 

[908ssp]

If one amp runs one pair of speakers and the other amp runs the other pair it wont be a problem.

I have a Radial Headbone VT for tube amps and it works very well. A nice feature is remote switching. That allows you to wire both heads and cab and switcher with short wires all in a stack if you want and run just one long guitar cable and a single switch at your pedal board to make the change remotely.

 

[ned]

Axess Electronics makes a head switcher as well the HS2.

http://www.axess-electronics.com/

You can also use an Axess GRX4 which would give you midi control.

 

[LHanson]

I do this. Have an old Carvin 4x12 that I've loaded with 2 Fender (Eminence, probably) and 2 Celestions. Wired the 2 fenders in parallel for 4 ohms, and the 2 Celestions in parallel for 8 ohms. I did make one mistake that could have been a disaster: I forgot the jack plate was steel. worked fine for one amp, but when the second one was turned on, a VERY disturbing noise was made. Swiped a trem spring cover off an Ibanez, drilled 4 holes on the corners and 2 bigger ones for the jacks, labelled the jacks, and it's done. I run my blackface Bandmaster through the Fenders and my .50 cal + through the celestions. I use an ABY switch, think it's a morley. Sounds pretty good.

 

[Bren10]

Don't do it without a head switcher. Remember, this is electricity we're talking about. It goes anywhere it can. If you use two heads and one speaker cabinet you'll have speaker level juice going from one amp to the other amp's output transformer secondary and thus the attached negative feedback loop. From there it will head on to the Phase inverter causing a lot of signal (potentially) to the output stage. So, the amp will send it's own speaker level juice to the first amp's O.T. where the process will start all over again. There's also a bigtime impedance problem with what your talking about. These two factors could lead to two dead amps.

Use a head switcher. Save a lot of repair cost.

 

[LHanson]

What I'm doing is really two cabinets sharing the same wood. There is no electrical connection between the two amps. Just clarifying.

 

[Bren10]

LHanson,
Yeah, I know. I was addressing keithus77. Your setup sounds pretty cool. Way use that spring cover. I allways take those things off and leave them off. You've actually found a recycling solution. Way to go!

So, with that switch, you can run either or both heads?

 

[LHanson]

LHanson,
Yeah, I know. I was addressing keithus77. Your setup sounds pretty cool. Way use that spring cover. I allways take those things off and leave them off. You've actually found a recycling solution. Way to go!

So, with that switch, you can run either or both heads?

Exactly. I thought about trying to put some sort of baffle between the 2 sets of speakers, but it sound great (and loud) with either amp on, and the tone with both on with a good crunchy tone is really great, I use it and a good tube overdrive to get my lead boost. :twisted:

keithus77 mentioned a quad stereo cabinet, so he might check to see if there is continuity between the two jacks of the cabinet. If there isn't, he might be good to go. Maybe a trip to a good amp tech would be in order. The other fun part is sorting out the ground loop potentials, which was pretty scary until I eliminated the "death cap" and grounded the Bandmaster properly.