[sdiy] Odyssey 2800 CV Mod

[deknow]

hi gene (and roland),

isn't it a good idea to buffer the input with and opamp (or two inverting
opamps) anyways?  or is that already taken care of on the oddy board?

deknow


----- Original Message -----
From: Gene Stopp <gene at ixiacom.com>
To: DIY List <synth-diy at dropmix.xs4all.nl>
Sent: Wednesday, April 17, 2002 3:55 PM
Subject: RE: [sdiy] Odyssey 2800 CV Mod


> Hi Roland,
>
> A quick question - is your intention to run the Odyssey from a MIDI-CV
> converter, to play it remotely as a sound module? If so, it's probably
best
> NOT to do my modification. The reason is that my modification sums the
> external CV with the internal CV from the Odyssey keyboard. This means
that
> when the Odyssey is not being played from its own keyboard, the
sample/hold
> circuit in the keyboard is holding the last note played (or some random
> value if the keyboard has not been played since power up). Since this is
an
> analog sample/hold it will drift over time causing the Odyssey VCO's to
> drift out of tune, either flat or sharp. You'd have to reach out and hit a
> key on the keyboard of the Odyssey all the time to keep it in tune.
>
> If you want to use the Odyssey as a sound module without touching its
> keyboard, then it would be better to add either a toggle switch or
switching
> input jack to disconnect the keyboard circuit from the rest of the guts
and
> replace it with the external CV. This will disable the keyboard when used.
> Now the VCO's should stay in tune at all times.
>
> The modification I did was to be able to control the Odyssey as a slave
> keyboard from another keyboard, so that one hand plays one machine and the
> other hand plays the other, transposed by the first.
>
> The Gate and Trigger input stuff should be the same.
>
> I don't have any drawings for this and my old schematics are deeply packed
> away, so I can give some advice but I can't go into very deep details...
> good luck!
>
> Best Regards,
>
> - Gene
>
>
> -----Original Message-----
> From: Sawtooth [mailto:pr0phet at gmx.de]
> Sent: Tuesday, April 16, 2002 9:50 AM
> To: DIY List; analogue at hyperreal.org; odysseypatch at yahoogroups.com
> Subject: [sdiy] Odyssey 2800 CV Mod
>
>
> Hello,
>
> is anyone here who modded his 2800 Ody with CV/Gate In/Outs? On the
> www.overacker.com ARP recource site is a description on the mod as I'd
like
> to do it, but unfortunately I'm still a newbie in DIY engineering, so I'd
> need some further assistance....
>
>