Vintage Synth Repair

In a message dated 8/25/05 1:10:06 AM, Jez <jezosaurus@...> writes:

<< Won't work from a Korg - Korgs are Hz per octave and Moogs are volts
per octave, so you've got the wrong control voltage coming in to the
CV.

Also, Moogs use a sort of inverse trigger, (S-Trig) so they respond to
the gate/trigger differently. >>

The Korg MonoPoly is actually the only Korg analog synth that does have 
Volt-per-octave response, unlike the others (MS-10, MS-20, etc), which hace Hz per 
volt response, so the MonoPoly and the Moog should play in tune with each 
other.  The problem quiet_channel@... is having is related to the 
Gate/Trigger.  The Korg outputs a positive-going gate, and the Moog wants to see a 
negative-going gate.  You'll need to build a simple one-transistor gate inverter 
circuit (made from one standard NPN transistor and two or three resistors).  
This circuit can be found on the web with a little bit of Google research.  It 
WILL fix the problem.

Michael Bacich

Thanks to everyone for their responses !

Not only does my Mono/Poly use V/Oct. . but the Trigger on the 
Mono/Poly is switchable between Negative and Positive. . and I did 
try it in both positions. .

Could it be that the Prodigy requires more than +-5V to be triggered?


-r scott


--- In vintagesynthrepair@yahoogroups.com, WeAreAs1@a... wrote:
> 
> In a message dated 8/25/05 1:10:06 AM, Jez <jezosaurus@g...> 
writes:
> 
> << Won't work from a Korg - Korgs are Hz per octave and Moogs are 
volts
> per octave, so you've got the wrong control voltage coming in to 
the
> CV.
> 
> Also, Moogs use a sort of inverse trigger, (S-Trig) so they 
respond to
> the gate/trigger differently. >>
> 
> The Korg MonoPoly is actually the only Korg analog synth that does 
have 
> Volt-per-octave response, unlike the others (MS-10, MS-20, etc), 
which hace Hz per 
> volt response, so the MonoPoly and the Moog should play in tune 
with each 
> other.  The problem quiet_channel@y... is having is related to the 
> Gate/Trigger.  The Korg outputs a positive-going gate, and the 
Moog wants to see a 
> negative-going gate.  You'll need to build a simple one-transistor 
gate inverter 
> circuit (made from one standard NPN transistor and two or three 
resistors).  
> This circuit can be found on the web with a little bit of Google 
research.  It 

> WILL fix the problem.
> 
> Michael Bacich