Sequential Circuits Prophet-600 Potentiometer Replacement

I received a Prophet-600 from an ebay auction. The shipping company shipped it in it's hard case, which you figure would be great protection. It was for most of the synth, but some jostle allowed two of the pots to catch on the inner foam and broke their shafts.

The seller got insurance, so I got reimbursed for damage by USPS (an easy and straightforward process!) and, instead of buying two pots from Winecountrysequential, I sought about trying to upgrade the lousy feeling old stock CTS pots. I couldn't find any modern exact replacements and chipforbrains seems to be in limbo these days.

So, inspired by the pots on my Poly-61, I went a different way: with some manipulation, I used a 16mm Alpha replacement which has the angled PCB terminals. Since the body of the pot is smaller and also doesn't have tabs for soldering to the PCB, the main mechanical fixation of the pots comes from mounting it to the panel at the bushing, using the washer and bolt. Also, the exact same knob is available from Mouser or Allelectronics that fits the 6mm knurled shaft.

This set documents that process. It was a bit of work, but if you're handy at soldering (and desoldering), it's very doable.

What I did here is relatively inexpensive ( < $50 for all the parts) and, imo, improves the feel and robustness of the Prophet-600. The pots turn more smoothly and feel more solid.

The pots I got from Smallbear (they are all 10k linear, matching the value and taper of the originals):

www.smallbearelec.com/Detail.bok?no=1058

and the knobs that fit these pots you can get from Mouser:
www.mouser.com/Search/ProductDetail.aspx?R=450-AE186virtu...

I'm considering now doing this to my Pro-One, which uses a 100k version of the CTS pot.