Lab Series L5

[bradicusmaximus]

I recently picked up an old Lab Series L5 solid state amp that needs some minor work - well, actually a lot of minor work, but so it goes. Every thing is pretty well intact and functioning but I came across an annoyance that's been driving me pretty much insane over the past few days. A little while ago, I threw up my hands, and figured I would go where someone might have a lead - even if it's not a tube amp.

I cannot seem to find the proper pots for replacement. I have two with broken shafts in the normal channel - a 50k log and a 2.5k log - and I can't seem to find an adequate replacement. Originally, they were CTS pots.

Has anyone gone through this exercise with one of these amps and, if so, do you have a part number you used for replacement. I'd prefer to get something relatively close rather than hacking in a standard pot. These are long shafts (1" - 1 1/4") with a d-cut. The pins are through-hole extending past the back of the pot. There are two tabs on the back for securing to the PCB. These are the original part numbers: 925-041426-004 and 925-041426-001.

I've done a search for the part numbers, targeted google searches for someone else doing this, and even examined the various pages discussing this amp as a shot in the dark. I've spent several hours going through both mouser and digikey as well as a run through CE's site. Wading through so many choices and possibilities has me frustrated. I can't seem to find an exact or somewhat similar replacement and I don't want to give up and make something else work ... yet.

Given the breadth of experience I've seen here, I have high hopes that someone else has done this and has some type of solution.

Thanks!

[ampdoc1]

I've been through the same process. Some months back I tried to find some pots for my gallien krueger 212G (circa 1975). They, and many others from that era simply aren't made anymore.

I think you have two choices:
1) buy a "parts" amp of the same model, OR
2) bite the bullet and wire in some readily available pots


Good luck
a'doc

[bradicusmaximus]

I kind of figured that's what I would be left with. This may prompt me to do something special with this amp rather than simply putting it back to normal.

Thanks for the response!

[Firestorm]

CTS pots can be fully disassembled so you swap a new shaft into the old pot. The design may have changed a bit over the years, so your sacrificial pots should be similar vintage. 50K reverse log pots are readily available, BTW. 2K5, not so much.