[sdiy] Prphet600 problems

[rtarcan]

Hi
I purchassed a broken Prophet-600 from EBAY and make it work(After some 
multiplexer changed). But there is still problems with it I think.

1-Frequency knob of VCO'S  controls octave not linearly
For example  when F-knob shows segment3,  pitch is  1 octave above 0 
segment, when shows  segment4 pitch is 1 octave above segment3. After 
segment6 pitch remains at 4 octave costant and knob does'nt kontrol the 
pitch.
2- It always retune  when I switched on.

The other knobs works well and pitch tracking is good when I  play .

If is this standart for a Prophet-600?

Thanks