Goliath JR II problem

Marley's Ghost · #1 10-09-2011, 09:28 AM

I picked up an old Goliath JR II a few years ago for $75 and have been using it at rehearsal with my Markbass LMII. Last week, the amp started overheating and shutting down about 5 minutes into playing. I suspect the cab is drawing less than 4 ohms due to a malfunction. I tried swapping speaker cables with the same result. The amp works fine with my Schroeder, so it most likely has to be the cab . It's probably not worth bringing to a tech, so i am looking for a fairly simple way to troubleshoot before I dump it. I have an old Fluke to use for testing.

BassmanPaul · #2 10-09-2011, 09:59 AM

Test the cabinet with a 9V battery. Ensure the cones are moving in the same direction.

Mugre · #3 10-09-2011, 10:03 AM

Buy a $9 dollar multi-meter a Rat Shack and follow the instructions you find via google for how to measure the nominal impedance of the cabinet. You'll learn something and you'll have a meter for which you can later learn other useful little tricks (like testing outlets in clubs before using them).

Kurt

BassmanPaul · #4 10-09-2011, 10:08 AM

Quote:

Originally Posted by Mugre

Buy a $9 dollar multi-meter a Rat Shack and follow the instructions you find via google for how to measure the nominal impedance of the cabinet. You'll learn something and you'll have a meter for which you can later learn other useful little tricks (like testing outlets in clubs before using them).

Kurt

You can't measure impedance that way. You'll be measuring DC resistance. That will come in at about a third down from the drivers actual impedance.