View Full Version : JBL L65 Brilliance adjustmentl issue / L-pad question / pot problem

07-11-2012, 08:11 AM
Hello. I have a pair of JBL L65A. They are in great condition. One of the works perfect. The other also works fine, only problem i have is the brilliance control for the 077 tweeter. The tweeter is fine and works 100%, just that the crossover control seems to not work. The midrange control works normally. The brilliance control, when adjusted, does not feel like it has any resistance from left to right. Compared to when i adjust the other tweeter and midrange controls that have a slight clicking noise when adjusted, this problematic brilliance control is very smooth when adjusted and is easier to move than the others. I have replaced caps before on other speakers, and i dont feel that is the issue with this. The wiring does not look to be by-passed either. Is this a need for a new l-pad, or cleaning pots?


I have included two pictures of each crossover. It looks that there are some slight differences in the components. If any help I.D. ing the differences (if any) would be greatly appreciated.

Mike F
07-12-2012, 11:38 AM
Sounds like the wiper is not making contact with the wirewound trace, that would explain the free and easy movement with no HF output.
You can carefully disassemble the L-pad to confirm it`s condition. Worse case scenario would be to replace, in which case is a simple and inexpensive fix.
Hope this helps.

07-12-2012, 02:17 PM
i did a through cleaning with deoxit which actually helped. your diagnosis sounds right. for future reference, do you know what type of replacement the L-65 takes. i see most pots are under $2.00 from partsexpres

07-12-2012, 02:50 PM
Here is an option, Speaker L-Pad Attenuator 50W Mono 1 "Shaft 8 Ohm
Parts Express Part #: 260-255

07-12-2012, 05:21 PM
i thought it would be a part such as 023-530 from parts x. a 10k ohm potentiometer.

07-12-2012, 05:24 PM
Sort of looks like that, but there are two wipers and conductive elements inside, and they handle a lot more power.
What's inside is more complicated than a simple potentiometer. Google L-pad.

07-13-2012, 07:06 AM
any idea of exact part specs or part number for JBL l65 (A)

07-13-2012, 07:27 AM
here are some pics of the problematic part. looking for replacement that would look stock in l-65.

07-13-2012, 07:47 AM
any idea of exact part specs or part number for JBL l65 (A)

JBL part number, 10285 8 ohm L-pad

Technical manual (http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L65A%20Jubal%20ts.pdf)

07-13-2012, 08:07 AM
after typing the JBL part number "odd" provided, i found a similar thread about JBL 4310 l-pad replacements that use the same l-pad as the l-65a


from what i read the part from parts express is

15w mono 3/8'' shaft 8 ohm part number 260-248

there is a second option from P.E., which had a 1 inch shaft.