I’ve modded my Minimoog Model D following the info on this page
http://analog.no/cms/index.php?option=com_content&view=article&id=52&Itemid=51
Unfort now the keyboard is not generating any CV pitch info, just gate. I can generate CV via Silent Way, although there still seems to be quite a lot of drift. Anyone got any ideas what I might have done wrong or how I can get the keyboard to start generating CV again?
Thanks!
First, I don’t like that mod. It could potentially damage the keyboard circuit on board #2 (especially FET transistor Q10 of the glide down section) by allowing power from an external control voltage to momentarily reach that circuit during insertion of a 1/4" jack until the switch actually opens and disconnect that board, if the external CV controller is already on and sending a control voltage.
The original way it’s connected routes the external control voltage thru a summing resistor on the oscillator board, and never at any moment is there any outside power coming back into the keyboard circuit on board #2. But if you insist on using this mod, I strongly suggest you plug one end of a jack in the Minimoog CV in first, and then the other end into the external CV controlling device second. That way, there won’t be any chance of damaging anything at both ends during insertion.
Second, there is a slight mistake in identifying the board where that C02A connector is situated. It should read “Connector C02A is the right connector on the inner right board (contour/keyboard)” not “(filter/contour)”.
Third, make sure that the switch on the CV input jack is operating properly when disconnecting an external CV signal, to allow CV from the keyboard to be routed to the OSC board again. (it may require cleaning if it hasn’t been used often)
And last, as you might have already done, make sure your wires are properly soldered (no cold joints).
Finally, and I sincerely hope not for you, the lack of keyboard CV control to the OSC board might indicate that the keyboard circuit on board #2 has already been damaged by what I’ve mentioned at the start. (either Q10 or Q14 or both)
My humble take on it. Take it FWIW.