Tom S. from this list originally ran me through this process. This is my version of his notes (thanks Tom!)
You can probably skip sections 1 and 2: the 4volts on the KAS board and the '0'volts on each individual 'M' board. Try first to go straight for the tuning procedure.
The 'M' board tuning is mainly done with the VR3 and VR2 - this is a VERY important part. This is the SCALE or SPREAD of the keyboard from one end to the other. You MUST understand this. It is very similar to setting the bridge on a guitar where the distance from either end where the strings are need to be exactly the same distance from the 12th fret.
Instructions (The following is done FOR EACH VOICE CARD - separately):
Plug your output into a tuner
Turn on the synth and let it warm up - at least 20 -30 minutes before starting.
Use the FLUTE patch or the panel. If the panel, turn everything off and just use sine wave with an envelope set to sustain it as long as I have a key pressed.
Set to Oct Up position
Center the tuning knob
Play a high note - the Yamaha service notes say a high C, but you could use the highest A for example.
Use a plastic/ceramic trimmer - not a metal screwdriver - as it will affect the pitch. You can get plastic trimmers from electronic wholesalers etc. You can also make one by cutting an old credit card etc.
As long as in the highest transposition you adjust VR3 (little blue multi-turn preset) on a note at the HIGH end of the keyboard
Then adjust VR2 while playing a note on the LOWER end of the keyboard, again, 'C' or 'A'.
Remember - it is the SCALE or SPREAD you are adjusting here. Every adjustment will affect the other one, and you will need to go back and forth between high note (VR3) and low note (VR2) until no more adjusting seems necessary.
Then move on and do the same for the other transpositions.
I am assuming here that you know and understand how to establish which voice card is playing. I usually switch the synth off and on again. My CS makes a little beep sound when it is ready to go. The first key hit will be voice card 1. If you get lost, switch off and on again, just to make sure.
To get voice 4 (for example) hit one key 3 times, then hold the third hit down while simultaneously adding the next note for voice 4. Release key for voice 3. Continue holding voice 4 and tune your trimmer while doing so
One point - the Yamaha manual says you can TOUCH the track to hear the distortion, so you know which voice card you are on.... DO NOT DO THIS .... you could blow the VCO chip!!!!! Turn off/on... voice 1 is the first note pressed. Sometimes you will hear a slight distortion as you put your hand - or screwdriver - near the presets - but DO NOT try to touch and tracks on purpose...! Static can kill chips.
best - DT
