A little help on my DBX 286A
TL;DR - I am looking for a replacement pot for pot #1 (the Gain pot) for this unit.
Well, I bought a used USA made DBX286A from eBay. Long and short of it, it came in damaged. I worked it out with the seller that I got a partial refund and got to keep the unit as I advised I could likely fix it. Great seller and I'm stoked to get it for $50!
It had 3 broken pots (#1, #2, and #3) and the SSM2017 had been replaced with an SSM2019 - poorly - cold solder joint and all. I tracked down some information and eventually found that Harman would sell direct replacement pots for #2 and #3, but not the original gain pot. I had temped some resistance in where the pots broke and was able to confirm that the unit was worth tossing parts at
I ordered the pots for #2 and #3 from Harman as well as an SSM2019 replacement (which arrived in the wrong form factor) I also ordered (Mouser) all replacement electrolytics for this (Nichicon 105c) and I also ordered the proper SSM2019 (DIP package) The only thing that I haven't sorted is the 6 or 8 non-polar caps that tricked this home-gamer in to ordering standard caps instead. I left the non-polar alone for now.
I'm still waiting on the DIP packages to arrive so I can replace the new pots and the chip. I suspect the chip is partially defective as it works, but the mic pre-amp doesn't have nearly enough gain to get to a yellow or red light on the display LEDs. I'm using an MXL990 mic. If I crank the gain pot, I can get in to the yellow, but only with overly-loud speaking.
My sticking point is pot #1. Harman advises that the original pot was "p/n 40-2131 POT 5K 5C 16mm ROT 41 CLK 15mm D-SFT HOR" and that it's no longer available. They also advised looking for a "Taiwan Alpha Electronics p/n RV16AF-20-15FW-05C5K-3FP1" I bought a pot from Mouser that is a 05C5K pot that fits, but it doesn't drive the gain like I have seen in numerous demo videos. Again, I suspect that 2019 is hooped. It also was covered in flux and had a cold solder joint.
If the one I ordered works, I will keep it in, but it does not have the detents that the factory pots do. I am terrible at shopping the electronics warehouses really and Mouser was a 2 hour shopping trip for caps.
Hope it wasn't too bad of a wall of text. Yes, I do have the schematics and the original BOM.
Thanks for reading and any help!