Creating an 'external amp in' into a combo

[goonieman]

Hi all,

I'm not a tech-head, but I know for sure I can figure this out with your help. Apparently I can use a 'switching jack' so that my amp re-routes to new amp head when its plugged in, but remains routed to stock AMP>CAB when unplugged.

Q1. What jack do I need please?
Q2. Pointers on wiring?
Q3. I presume I will not need any dummy loads or any 'funny stuff' like that. I read somewhere that speakers should not be unplugged while the amp is on, etc. I'm pretty worried about creating an accident waiting to happen.
Q4. Can I presume because my amp says that the external speaker out is 4 ohm, that the internal speakers themselves are 4ohm? (no other way to tell because the speakers are closed off in the cab)

thanks!

[dincz]

Not sure what you're trying to do. Do you mean you want to send the output of an external amp head to the combo's speaker?

[Grangur]

I've got a Mark Bass CMD121P combo that has a jack lead from the integrated amp that plugs into a socket to the integral speaker. I guess this is the sort of solution you're looking for.

If you would like help to do it, maybe telling us the make and model of the combo would help. Pics would be even better as we aren't all familar with all combos.

[Delberthot]

I had a Trace 1110 4x10" combo that had an external power amp in but I think it was done at the Trace factory.

I expect that it would come in handy if you used a combo (like I do) and the head failed - if you carry a spare head then it means just plugging it in rather than having to carry a second rig