[sdiy] Odyssey 2800 CV Mod

[Gene Stopp]

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....