[sdiy] Jp-8 head scratcher

[Maarten Halmans]

Hello Florian and all,

autotune on early Oberheims works this way, the JP-8 seems to measure at 3 
different frequencies with C5, C7 and C8. In the service manual there is 
mentioned only 2 frequencies with 5 octaves apart. If only absolute tuning 
is done there is no point in taking measurements on two/three frequencies. I 
also tried to find out how accurate the oscillators must be tuned and scaled 
to get the pitch right, scaling can be off for a semitone over 3 octaves and 
autotune corrects it. Takes a little more time. The same applies to absolute 
tuning.
More head scratching to be done....
Best,
Maarten


> As far as I understand it, the autotune does adjust only the absolute 
> tune, not the octave tracking. So you simply made a mistake while you 
> adjusted the octave tracking. I assume you enabled autotune in between, 
> and forgot to disable it again when you adjusted the octave tracking 
> manually. The synth must be adjusted manually completely perfect - it must 
> sound like an angel without using autotune.
> I recommend to do the complete tracking and absolute tuning adjustment, 
> then leave the synth switched on, close the panel, wait for another 30 
> minutes (the synth will heat up a little), then check the tracking and 
> tuning again.
>
> Florian