Help With JBL 6290 AMP Knobs

[gsb001]

Hi Everyone,
I'm looking for part numbers / sources for one pair of knobs for a JBL 6290 amp.

I found the Security Cover Caps: part # 6200SC. No luck on the knobs.

Thanks
Steve

[mech986]

Can't find anything about part numbers in either the 6290 owners manual or the current JBL parts list but not surprising as this is a 20 y/o amp.

Best to call JBL Pro parts department and see if they have either the knob or the security covers. If not, then take a pic of the exposed pot control shaft and we'll have to see if something could be done.

Also might look for a parts unit, they sometimes show up. Good Luck!

[Jorre Pulle]

Hello to all,
I do own 3 JBL 6290 power amplifiers all with the security covers in place.
The volume knobs were not included in the package when i bought them (second hand).
A few weeks ago i raised the volume of one channel with the amp still on and touched by accident the PCB with one finger:the 90vdc rail voltage is not pleasant to feel!!
So if someone can get in touch with a supplier of those volume knobs please drop me a line cause i'm looking for them too.
Thanks in advance.
feel free to mail: [email protected]

[mech986]

Well, I just checked with JBL Pro and both the knobs and security covers are No Longer Available (NLA). Pretty much expected this as the amps are almost 2 decades old.

I'll have to pull the knobs off of mine and see exactly what the attenuator shaft/spline looks like (diameter, length, and configuration) and the diameter of the opening. With that, we can then search for an appropriate potential replacement.

Bart

[gsb001]

Bart,
Thanks for the help -
Steve

[mech986]

OK here's some pics of the knobs off my 6260 which are the same as the 6290.

overall diameter 1 1/8"
Total depth 1 1/4"
Shaft spline depth 3/8"
Shaft diameter 1/4" splined

Due to the knob being a hollow finger hold type, a deeper knob with knurling may work or a knob with a bar type control surface may work. Plastic probably would be better than metal since there may be conductive surfaces in the recessed area this works in.

[gsb001]

Hi Bart - thanks so much for the details. Very nice of you to take the time.
Steve

[mech986]

Glad to help, sorry that there is not an easy solution yet.