As far as I can remember, it should be a 10k linear (sometimes called type 'B') slide potentiometer. Should be 60mm long with a 15mm shaft and 45mm travel. The Volume and Data pots should be the same. But it's simple enough to double-check all this yourself. Not really something needing schematics,...

I am looking for the original manual for the Maplin 5600S. Thanks, Hi there, I had a quick wander around the net and found this - hope it's useful! http://www.eti4600synthesiser.org.uk/maplin%203800%205600%20synth%201%20of%202.pdf http://www.eti4600synthesiser.org.uk/maplin%203800%205600%20synth%20...

Ensoniq VFX, VFX-SD, SD-1: Service Manual https://drive.google.com/open?id=0B44NKm9yPA1baU1kWWRGdjhickk Ensoniq - Service Bulletin #13 (keyboard problems) https://drive.google.com/open?id=0B44NKm9yPA1bV0wwYTN4akNNWkE Schematics https://drive.google.com/open?id=0B44NKm9yPA1bRURVMDQtUF9JYWs These are...