Arp 3620 questions, pt. 2

[Mintlake at aol.com]

In a message dated 4/2/97 10:01:53 AM, brandt at fishes.ultra.net (Josh Brandt)
wrote:

<<The tracking from octave to octave appears to be a bit off when using it to
play a Korg Mono/Poly. There were four trim pots on the circuit board when I
cleaned out the dead bugs and replaced the jacks. Does anyone have
documentation on exactly what these do? Is one of them a V/Oct calibration
trimmer? This would be ideal. 8)
>>

Are you asking about the 3620 or the MonoPoly?  You need to start with an
accurate reference if your using the 3620 for controlling multiple devices.
 Check the CV output for 1 volt /Octave plus or minus 5 mV.  You need a 3 1/2
digit multi meter.  You can usually scale the cv out to within plus or minus
about 2 mV error.  Then calibrate the VCO's to that reference.  

If you are just using the one synth, and don't have the multi meter to test
the calibration of the key CV, you don't know if the synth or CV or both is
out.  It doesn't matter until you add to the system and need three or more
pieces to track.  


















	
Check for silk screening or etching on the PCB to identify the trim pots.
 There is frequently some designation as to their function.  The 3620 info I
can provide.  The MonoPoly docs don't include any layout info as I recall.
 The schematic I remember having must be archived in some old boxes from a
previous move and would take some effort to locate.

Larry Church