I have a vintage Kustom 500 bass amp 6-15AB-1.... one cabinet off the 250 head and the other with the power module inside. From age several cones are bad and I'd rather replace than recone. I keep getting conflicting opinions on the speaker ohms....some say 8 others say 16. So I'm looking for some accurate info as well as the best speaker for replacement. Thanks in advance everyone
stevem Messages: 4733 Registered: June 2004 Location: NY
Senior Member
If you want the most power out of both of them then you want 8 ohm drivers wired in parallel fir a 4 ohm load on the head and the cabinet power unit.
The earlier 200 series heads used cabinets that housed 16 ohm drivers wired for a 8 ohm load, this let a model be sold with two cabinets that when hooked to the head did not load the head with less than a 4 ohm load.
The down side was that when sold with only one 2-15" cab which made for a 8 ohm load it made the head only output some 72 watts of clean power and not 100 like with the 4 ohm load.
Since the 250 series heads when sold with a extra cab like your powered one, they where fitted with 8 plum divers and is why these amps sounded so much puncher than the 200 series amps!
Not sure on the speakers...I bought this used @ 1980 and used it 6 nights a week until 2006. Switched to sax until now so it's been just sitting. Now that I'm firing it up again it seems every other week I'm having a bad speaker....so really looking for a good replacement speaker(s).
I don't know what a model 500 bass amp is. I don't know what speaker load it is looking for, but if it was working well with the speaker cab that you have, you can measure the dc resistance of the existing speakers and use that as a guide. The dc resistance will not quite match the 8 or 16 ohm values, but will be good enough to tell what was in there to start with.
Okay, I looked it up and it's a 250 head with a powered cabinet upping the wattage to 500 watts.