Korg MS-20

MS-20 modifications are easy to implement and a lot of them are detailed described in the Net. After some research i want to try :

- Buffered VCO Outputs for VCO1 and VCO2 (patchable on the top of the case)

- PWM Input for VCO1 (patchable on the top of the case)

- Additional CV Input with ability for transponation over the internal keyboard (patchable on  

   the top of the case)

- Oscillator Synchronization (switchable on the back of the case)

I found this solution for a additional CV Input for both VCO's. It is perfect, if you want to transpose a CV-sequence with the internal keyboard. This easy mod will make this job. If I remember correctly I found it on Doepfers Homepage ..

I added a 10uF non-poled Capacitor to allow only AC-Control Voltages as PWM-sources.

In sum this modification is rather unspectacular.

Buffer- and CV-Input Board. There is enough room inside the MS-20 to place this little board. The supply voltages are easy to find on the MS-20 Mainboard.

The simple solution with a switchable diode doesn't work properly if the wires to the switch are a little bit longer ... In my case everything was quiet after i close the sync switch.

I added a little relais that is located directly on the mainboard so the wire-length doesn't matter anymore.

The sound of the synced VCO's is very "special" ... if you want great Sync-Sounds then look after a Moog Prodigy. The Prodigy is definitely the master of synced VCO's :o)