Wanted to share this mod to fix the slide pots on a UREI 535 EQ. I have 3 of these and all 3 have been upgraded with this kit. It’s a new PCB that accepts Bourne slide pots. They have directions on their site but I thought I’d share my tips for those of you wanting to do this.

First pic is of the old pots and how dirty they are. This was the worst I’ve seen of the 3 I have. They were almost impossible to move. No amount of love can save them from this condition.

Next pic is of the new pots mounted on the new PCB. They solder right on. There’s not much room for play left to right so I just solder them to the PCB making sure they are all the same height. The instructions have you mock up the PCB but I found an easier way that allows for adjustment at the end.

Next you have to drill holes for the new PCB to mount to the old one. I mock it up at this point partially assembled and the unit sitting with the face facing up. This part is similar to the instructions but the slide pots are soldered on. This allows you to center everything with the face plate set in position. You mark the old PCB and drill oversized homes: I used a 1/4” drill bit. Then you can solder the connecting wire per the instructions and then mount the new PCB. Looks like this. Those are 3/4” spacers with 1 1/4” machine screws and buts. #6 I believe. Lock washer and washer on the nut side. You can see in one picture the PCB is warped a bit. I fixed this by drilling the holes a little larger to relieve the tension. The oversized holes now allow you to shift the new PCB around until everything is lined up correctly.

Here are before and after pics of the faceplate not aligned properly and then aligned properly after shifting the new PCB.

Here’s the last pics of all three in the rack and a pic from the inside of the 1/4” jacks I added. I use these on kick, snare, and toms post compression. They are a gyrator design which is proportional Q. They have an output transformer and have a nice sound. I recap them and drop in lme49740’s with decoupling. They already have WIMA and EVOX films so I leave them. Two of mine had electrolytic caps in place of the tant’s and one still had the tants in the audio path.

Thanks for posting this- I'm doing this mod on a 535, and it's certainly not for the faint of heart.

Thanks for posting this. I'm in the middle of doing the mod. I didnt follow the directions and soldered the faders first. I don't know how you are supposed to line up the holes on the JJ board with the control board when the control board is on top of the JJ board. What I did was line up the jj board to the front panel, tape it in place, then put puffy double sided tape on the back of the JJ board, placed the control board on top of that lined up with the front panel, then drilled holes in the control board using the holes of the JJ board as a guide. We'll see how it works out. Might have to drill bigger holes to have some wiggle room to line the faders up with the front panel at the end. The whole operation has not been as easy as I had hoped but hopefully it will come out aok.