I recently cleaned the j-wires and re-calibrated my Sequential Circuits Pro-One. I cleaned the j-wires and the contact bar with isopropyl alcohol and cotton swaps, although proper contact cleaner is recommended. I also gently bent a few of the wires to improve the connection to the contact bar.

I knew about the calibration problem prior to any of this maintenance, but I noticed it even more after cleaning the j-wires. I’m not sure why this would be the case, but I resolved to take a stab at the calibration myself having not attempted it before. Looking on the scope I could see that an octave on the keyboard was actually a quarter tone sharp and therefore unplayable. I made the necessary adjustments for both oscillators and now it sounds great.

After the calibration I produced this sequence entirely on the Pro-One in a single take by programming two short sequences into the on-board sequencer. The first sequence was played at several pitches to create a progression. I also switched off the oscillator sync at the same time I switched to the second sequence to create an octave doubling of the melody then re-enabled the sync at 1:41.

Pro-One-Sequence-Calibrated