Vintage Synth Repair

Hi all,

my Odyssey I (model 2800) gone nut from a day to the morrow. Let that way 
few years during, I recently decided to cure it :
- downloaded & printed the Odyssey Service Manual
- cleaned KBD contacts
- began the maintenance procedure as far as no oscilloscope was needed 
(power supply and VCO calibrating).

I suspect a keyboard issue. Symptoms :

- even thermally stable, VCOs still unstable. No significant freq drift 
while a key maintained depressed, but playing the same key doesn't produce 
the same freq.
- octave requires more than 12 notes (from C to somewhere-between-C#-and-D)

I don't if there is a link, but :
- LPF range is limited to the 25% upper cursor range (i.e. everything is cut 
off fom 0-to-75% of the cursor range)
The cursor is noisy : I'll really have to change it.

- VCOs however provide the waveform they should (Saw, Squ. & various PW). 
Transpose, hard sync and RingMod OK.
- other stuffs (noise, HPF, S&H, Mixer, LFO and EGs) seem working fine

Once again, the beast used to work pretty well.
Does anyone have a keyboard calibrating procedure without the need of an 
oscilloscope ?

Thanks

Fran\ufffdois

_________________________________________________________________
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d\ufffdcouvrir tout ce qu\ufffdInternet a \ufffd offrir. 
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Hi all,

my Odyssey I (model 2800) gone nut from a day to the morrow. Let that way 
few years during, I recently decided to cure it :
- downloaded & printed the Odyssey Service Manual
- cleaned KBD contacts
- began the maintenance procedure as far as no oscilloscope was needed 
(power supply and VCO calibrating).

I suspect a keyboard issue. Symptoms :

- even thermally stable, VCOs still unstable. No significant freq drift 
while a key maintained depressed, but playing the same key doesn't produce 
the same freq.
- octave requires more than 12 notes (from C to somewhere-between-C#-and-D)

I don't if there is a link, but :
- LPF range is limited to the 25% upper cursor range (i.e. everything is cut 
off fom 0-to-75% of the cursor range)
The cursor is noisy : I'll really have to change it.

- VCOs however provide the waveform they should (Saw, Squ. & various PW). 
Transpose, hard sync and RingMod OK.
- other stuffs (noise, HPF, S&H, Mixer, LFO and EGs) seem working fine

Once again, the beast used to work pretty well.
Does anyone have a keyboard calibrating procedure without the need of an 
oscilloscope ?

Thanks

Fran\ufffdois

_________________________________________________________________
Des m\ufffdcanismes de contr\ufffdle parental puissants permettent \ufffd votre enfant de 
d\ufffdcouvrir tout ce qu\ufffdInternet a \ufffd offrir. 
http://join.msn.com/?pgmarket=fr-ca&page=features/parental&ST=1&xAPID=1983&DI=2043 
Commencez d\ufffds maintenant \ufffd profiter de tous les avantages de MSN Premium et 
obtenez les deux premiers mois GRATUITS*.