Need help! Bypass speaker in combo. No ext jacks to add a cabinet.

[daa709]

Hello,

I have a Marshall Valvestate 8080, and i want to add a cabinet to it, buut there are no ext jacks or anything, just a low power line out. Does anyone know a way of disconnecting the combo speaker to then add a cabinet, but then go back to the speaker if i needed the versatility of a combo??
I have access to wiring, but i dont know what plugs/wires/adaptors etc to use.

Thanks!!!

David

 

[boingoman]

Buy a 1/4" female inline jack. Wire that to the amp's speaker output cable. Wire a male jack to the internal speaker. Now you can do what you want. You will need an extra speaker cable to hook up an external cab. That is the simplest way.

You will have to figure out a way to make the connections accessible. Either you will have to have a couple things dangling, or you could make a small patchbay on the back of the amp, with two panel-mount female jacks, one for out and one for in to the internal speaker, and use a short jumper to hook up the internal speaker when you want to.

You could also have a panel, one panel mount female jack and a heavy duty DPDT switch that switches the output from the internal speaker to the external jack.

Find out the impedance of the internal speaker, and make sure you get a cab with the same impedance.

 

[daa709]

Awesome.

Thats the exact information google hasnt been giving me!!

Thanks alot

Dave

 

[boingoman]

One other thing- never, ever run a tube amp with no speaker attached.