Doepfer

Hello

Am 30.10.2014 04:54, schrieb sj230962@gmail.com [Doepfer_a100]:
> 1. I set [SW1] to 0= middle, and [P1] to 5 =middle to start with.   I
> then checked the range of [SW1] by turning +/- 2 octaves and tried to
> calibrate with [P5] - the range potentiometer.  Whilst the tracking was
> a little off +/- 1 octave from 0 (ie 20-40 cents), by +-2 octaves the
> offset had increased to over 100 cents.  How can I adjust [P5] so that
> the range steps are equal...?  I didn't seem to find any setting that
> gave even close to a 1 octave per switch movement.
You first have to be sure that the general octave tracking is perfect. 
(trimmers P7 and P8). This has to be done usinge your MIDI/CV-interface 
or your standard CV-keyboard. Do touch P1, P6, and the octave switch 
while doing these adjustments.

Unless this octave tracking works perfect for all four VCOs you should 
not start with the range adjustment of the octave switch.

After you verified that this general octave tracking is good, you can 
adjust the tracking for the switch with P5. This may come close to 
perfect, but not really perfect.
The reason therefor is: Unfortunately the tracking of the octave switch 
depends not only on P5, but also on the relation between the resistors 
R1(+R1'), R2, R3(+R3'). Their outcoming resistance of their combination 
has to have an exact relation of 1:2:4. It is unimportant whether the 
individual resistors are exactly 150k. But it is very important, that 
these resistors are truely equal within each other.



> 2. Dumbass question, but should the VCOs be producing C with [P1] at 0
>   = fully anticlockwise, or at 5=middle position ?   My 4 VCO's all seem
> to tune closer to A at [P1] = 5 = middle position.
Simply adjust it with P6

Florian


PS:
 > Malaysia isn't a hotbed of analogue synth aficionados.
I once had the opportunity to buy a Jupiter 8 from Malaysia - 
unfortunately I was not successful. But from the communication with the 
seller it seemed, there are is a vivid music scene.