Two heads one cab?

What Ampeg 810 do you have ??

http://www.ampeg.com/pdf/SVT810EAV.pdf

 

More importantly what are the amplifiers you intend to use??

 

A setup like in that Ampeg manual would work, but if you want to "switch" between heads (rather than using both at the same time), you'd be wasting half the size/weight of the cab, since you'd only be using 4 10s at a time.

A better option (although more expensive) would be a head switcher. I know Radial makes one, I think it's called the Head Bone and costs about $250. That would allow you to run speaker outputs from both heads into the switcher, and then a single speaker cable out to the cab. This way when you switch the heads, you get the different sound of each head, but with the full 8x10 reproducing it (rather than half).

It really depends on what you are after what setup would work best for you.

 

+1 for the radial headbone. Otherwise it's 2 amps with a 410 each.

 

Before this is even attempted we NEED to know what amplifiers the OP is contemplating using. If one or both are tube heads the requirement of a dummy load on the idle amp needs to be addressed. If the Headbone fills that requirement then fine.

 

I think with the Headbone, you also run your input through it (and then to the front end of your heads) and then it uses relay switching so that as you switch the speaker output of one head to the other, it also cuts out the input signal from one head to the other, which should obviate the need for a dummy load.

 

I assumed that op just wanted to run the amps in his profile (Peavey Mark viii and GK 1001rb-2) at the same time. Both came be run with a 8ohm load. But I may be wrong that he wants to run both at the same time. If thats case a Headbone or Lehl dual amp switcher would be the answer..

 

That's what he asked. Which is why I suggested the Head Bone.

 

Why not run them both slave one of the heads... take the line out from one amp and run it into the imput of the other amp... the line out only sends a signal no power so it wont hurt the slaved amp. then plug the amps in normally just use a speaker cable from each head... simple... right?

 

That doesn't matter, the issue is that an amp with an output transformer needs to be connected to the proper impedance load or you risk blowing the tubes or transformer. The headbone VT and TS contain load resistors so you can use two tube heads or a tube head and a solid state head respectively. The only issue you'd run into in this way is that load resistors supply an 8 ohm load, so it has to be a tube amp capable of an 8 ohm setting.

 

Tube amps (unless they have shorting jacks) need to be connected to a load (speaker or dummy resistors). That said, assuming you have that all sorted out, you could do it with a simple AB switch but never run a Y switch. Running 2 amps into 1 cab means you're going to lose both amps and maybe the cab.

This is a pretty simple scenario using ss amps, with tubes, you have to see that the amp not being used in a particular switching scheme is still connected to some load be it a quiet speaker or a bank of dummy resistors.

 

NO IT DOES NOT!!!! A tube amp while operating NEEDS to have a dummy load or a speaker load connected at all times. That's tube amps 101 stuff!!!

 

Weber makes one, but it is limited to 200 watts per head (adds a dummy load to the head not running the cab). Not sure if that will work for you:

https://taweber.powweb.com/store/2head.htm

 

Unless of course the tube head has a built in dummy load, allthough can't think of one off the top of my head I know there are a few out there with this implimatation.

 

Even if the amp has a dummy load built in it would be defeated by plugging in a speaker plug, just like a shorting jack will be defeated.

I don't suggest building your own switch, if the two amp outputs short to each other during switching one or both may be damaged! If your cab is the stereo 810 you cab switch the cab to stereo (dual mono). Attach one amp to the upper section and the second amp to the lower section. Keep in mind if you want to give the amp attached to the lower section a fair shake you need to step WAY away from the cab to listen. Up close the lower section is entertaining your knees.