Voice cards that have not been serviced can result in autotune failing, and the voices not sounding right and inconsistent from voice card to voice card even when autotune succeeds.
The original electrolytic capacitors have long since dried out and stopped performing as they should. This kit contains high quality electrolytic capacitors to replace these failed or failing capacitors and provide decades of stable operation. We provide quality, name brand, long life capacitors. Gold audio grade capacitors are provided for the signal path. Also, metal film resistors are provided to replace several key resistors that will improve oscillator stability.
One of the challenges in calibrating and tuning the OB-Xa is the cheap single turn trimmer pots used. The original single turn trimmers on the Oberheim voice cards are nowhere near the precision they need in order to properly tune the oscillators, filter, and VCA. Barely touching a trimmer it’s easy to overshoot the calibration, and forget about getting a precise tuning. This kit includes replacements for all 15 trimmers on each voice card, which will allow for tuning so precise, it may not be necessary to use the Autotune when the servicing is complete! Plus, you will proactively eliminate problems from worn out, damaged, or defective trimmers. And often times I will come across OB’s that have the trimmer knobs glued in place (from the factory or someone else) that can’t even be adjusted without ruining the trimmer.
Additionally, the voice selection DIP switch block found on the pot board (which is used to disable or enable voices) oxidizes over time and can causes voices to fail. This kit includes a new DIP switch block, and replacements for the polarized capacitors found on that pot board.
This kit contains parts to service 8 voice cards. Included is a parts layout for the voice board and a checklist to make installing these easier. This kit requires intermediate level soldering skills (the trimmers are not drop in replacements for the old single turn trimmers), and the voice cards require a full calibration after installation. If you’re not comfortable installing this kit and calibrating your synth, please contact us about installation services.