What to do with a fried JBL PB12

[tarpon]

Well my JBL PB12 gave up after three years of careful service. Truly a bad design. Just starting buzzing late one night and then poof. The amp burned out, crisp.

So what can I do with it? JBL has offered to replace it for $250, about what I paid originally, so much for them and lousy customer service. I think I would prefer buying another brand after all I have read about JBL sub woofer products. No point in throwing good money after bad.

Any ideas? I have a modest system in a smallish room. Doubt I ever used the 250 watt capability of the PB12. I am fairly handy with a soldering iron, and building electronic things doesn't bother me at all. The down firing speaker is fine and enclosure is in good shape.

Thanks in advance...

[qguy]

1. have you tried having the plate amp repaired
2. buy a new plate amp, take a look at partsexpress /madisound
3. got a spare integrated amp ?. if you using an HT avr with a subout, you can connect the subout to an integrated amp aux in and then drive the JBL woofer using the integrated amp.

[tarpon]

I talked at length with JBL, and they have discontinued the PB-12 product and all repairs. Some customer friendly policy for a three year old 5.1 system that cost $2000 total new. They will give me a replacement for what I paid for this one, here is the catch it comes with a one year warranty on the electronics, just like the first one -- $250 fuses is how I see it.

So I have a perfectly good cabinet, a good 12 woofer and no amplifier. Looking around on the site you suggest, there really is nothing that will 'plug in' to the hole in the sub woofer cabinet.

I may try and rig up a spare amplifier with the LFE output doing the driving. I wonder though, will the main amps LFE output give the proper base drive? I know you have to combine both right and left channels into a mono signal for the sub base, the amp will do that, -- but after you do that, does it just work or is it just going to be a bust? Going to be a kludge at best.

No more $250 JBL fuses for me.

[steveb1475]

Bump on this one...
I'm in the same boat. Do you know what fried on yours? The "black box"? The small transformer on mine looks like it got a bit hot.

[Geoff H]

Tarpon, welcome to the nasty world we have. It gets up my nostrills hearing about this sort of thing. I see plenty of it with computers.

I think I know what brand you won't be buying now on.

Usually when power amps blow, the O/P transistors and drivers go short circuit. It could be just a matter of replacing those, and it's up and running. But then, if the problem is further back, the lot could go up in smoke again.

The first thing is to obtain a circuit diagram, and that's not always easy.

Geoff.

[rcanglin]

try searching around...there's a thread on another forum with pages and pages of detail as to the problem(s) with these amps and how to repair

[ohprojectorman]

I had the same problem with my PB12. I drilled a small hole in the face of the plate amp and ran some speaker wire to the sub from an external amp. Sounds great!

[rcanglin]

read here

JBL PB12 subwoofer, Class D amp, dead.

[Starflight]

This is brutal!!! I have to admit that I'm also in the same boat. I had this problem for a while but just 2 days ago, the amp went rapid fire bombing on me and now I'm scare to even plug the damn thing on! Attempts at emailing JBL have failed. I'm so mad cause I never really used this sub for all the years I've had it and now that I read so many people having the same problem too...

I guess I should have done better research way back then. But yeah...