Yet another crazy amp/speaker question

pintspiller

@icbm has already given me advice on a thread elsewhere regarding floor monitors, but I'd also like to ask a general amp/cab question.

I presently run my Sound City 50+ into a Hartke Transporter 410. And it's a great setup for my needs (I play bass in a covers band).

Our second guitarist uses a 40w Valvestate combo, which is also miced up to the PA.

I was wondering if we could share my cabinet as it has two quarter inch sockets at the back. Presumably I'd need to change my settings on the SC from 8ohms to 4ohms. Provided his Marshall has a "speaker out", his output ohmage would be ok with a solid state amp. 

ICBM

Do NOT do this.

You will very likely damage one or both amps.

The two sockets on the cabinet are in parallel. This means that if you plug two amps into them, the amps will be connected together - depending on the phase of the two signals at any given time, they each will be trying to drive the other amp as a zero-impedance load (dangerous for the solid state amp) or a very high impedance load (dangerous for the valve amp). That's a little over-simplified, but close.

You can *only* plug two amps into one cab if the inputs are specifically designed to split the speakers between the two inputs, in stereo, bi-amp etc. If the jacks aren't labelled, never assume this is the case.

pintspiller

< phew >

Wouldn't have done it without asking somebody beforehand