Sequential Circuits Pro-One

I have finally started restoring my Sequential Circuits Pro-One. My plan is to get it as close to mint condition as possible and start using it again for recording and perhaps performing. Once I started using the Korg MS2000, I neglected the Pro-One and it fell into disrepair. Over time the key contacts became dirty and inconsistent. At some stage one of the knobs was broken off and lost, leaving a stub of potentiometer protruding uselessly from the control panel.

The first thing I did was clean the pots. For you laymen, pots is short for potentiometers. In other words, I wasn’t diverted by dirty dishes. To clean the pots I removed the knobs and then squirted a few drops of a greaseless lubricant called LPS-1 around the post. The stuff works wonders on crackly volume knobs and was recommended to me by the electronics experts at AEI Electronics in Minneapolis years ago. I’ve been using it ever since. After applying the LPS-1 I made thirty or more rotations of the pot from zero to maximum so that the dirt particles were worn away by the fluid.

I put the thing back together and did some tests. The knobs no longer had anymore crackling going on, so that was fixed, but the keyboard was horribly inconsistent. The Pro-One uses a J-wire keyboard with open air connectors that are prone to collecting dirt (or residue from malted beverages spilled over the keys). For a close up view of the Pro-One J-wires check out this post on MaxtrixSynth. Another problem is that the J-wires can become less springy, making the connections a bit weak. I used used q-tips with a drop of LPS-1 to clean each J-wire and the metal bar that they connect to when the key is depressed. I also bent the J-wires slightly to improve the tension. After all that I tested it again to find it working flawless, although still a little difficult to tune. Next up I’ll be replacing the missing mod wheel, the broken potentiometer, and the missing knob.

Pro-One Dub

Having been asked on more than one occasion, it is about time that I posted a sound from one of my favorite synthesizers, the Sequential Circuits Pro-One. This is actually two layered tracks of sounds I made with the Pro-One today in a session with Nils Westdal. The sounds are effects for a dub track at 73 beats per minute. I ran them through a couple of tempo delays and reverb to create some atmosphere. Even after using this instrument for more than ten years I still manage to get new sounds out of it. Perhaps it’s the unpredictability of the analogue oscillators and filters, or the fact that you cannot store presets, in any case it seems to breathe and even sometimes cough as if it needs to wake up a bit before behaving consistently. The short story is that this simple mono-synth from the early 1980’s has a lot of character.

Pro-One Dub