What to do with a fried JBL PB12 - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 28th November 2006, 07:36 PM   #1
tarpon is offline tarpon  United States
diyAudio Member
 
Join Date: Nov 2006
Default What to do with a fried JBL PB12

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...
  Reply With Quote
Old 29th November 2006, 04:30 AM   #2
qguy is offline qguy  Canada
diyAudio Member
 
Join Date: Mar 2005
Location: Burnaby
Send a message via AIM to qguy Send a message via MSN to qguy Send a message via Yahoo to 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.
__________________
na
  Reply With Quote
Old 29th November 2006, 06:41 PM   #3
tarpon is offline tarpon  United States
diyAudio Member
 
Join Date: Nov 2006
Default Tried that, no repair available

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.
  Reply With Quote
Old 2nd December 2006, 01:08 AM   #4
diyAudio Member
 
Join Date: Dec 2006
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.
  Reply With Quote
Old 3rd December 2006, 05:59 AM   #5
Geoff H is offline Geoff H  Australia
diyAudio Member
 
Join Date: Oct 2006
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.
  Reply With Quote
Old 11th December 2006, 03:39 AM   #6
diyAudio Member
 
Join Date: May 2005
Location: Tyler, TX
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
  Reply With Quote
Old 13th December 2006, 06:41 AM   #7
diyAudio Member
 
Join Date: Dec 2006
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!
  Reply With Quote
Old 15th December 2006, 02:43 PM   #8
diyAudio Member
 
Join Date: May 2005
Location: Tyler, TX
read here

JBL PB12 subwoofer, Class D amp, dead.
  Reply With Quote
Old 27th December 2006, 10:36 AM   #9
diyAudio Member
 
Join Date: Dec 2006
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...
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
JBL PB12 replacement amp Tee-Bruce Subwoofers 1 18th June 2007 01:59 AM
schematic of my future D amp for the pb12 pat allen Class D 122 23rd April 2007 09:47 AM
JBL PB12 dead? turkish621 Subwoofers 10 28th May 2005 01:11 AM
JBL PB12 Amp Failure Galen Multi-Way 3 28th November 2001 08:01 PM


New To Site? Need Help?

All times are GMT. The time now is 05:50 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2