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.
Here’s a loop that I played on my Korg MS2000 during a recent jam session. I was sending the MS2K an external synchronization signal via MIDI and it sounds as if the instrument was laboring to lock in with the clock. 
I have lots more from Spark that I would like to post, but it needs some sorting through, so here’s something of my own for now. This is an arpeggiated loop of a synthesized clavinet chord filtered in real-time with the cutoff frequency on the instrument, which happens to be the Korg MS2000. After looping it I ran it through some gentle amp modeling followed by two ping pong delays. One set very short and another set much slower. The short delay has a lot of feedback and almost sounds like reverb, while the long delay is creating the echo.
Here’s another example of audio that was recorded for the purpose of live looping during a performance. 