Discussion about the Korg PolySix synthesizer

Hi and welcome to the list!

1) PWM:
    IC13/pin1 should change in the range of -5V .. +5V with the front
    panel "PWM SPEED" knob.
    You should see on IC20/pin12 a sawtooth which changes the period
    with the PWM SPEED setting. If it is not there, IC20, IC15, or C32
    are defective; I would go for IC20 (a LM13600) first. But C32
    could be a faster (and cheaper) try ..

2) ADSR:
    Does the envelope work for the filter?
    As with the PWM SPEED the first thing to check are the control
    voltages output from the D/A converter - demultiplexers - hold
    amplifiers: IC10/IC11/pin1/pin7. Each must swing from -5V to +5V.
    Plus the EG mode switch: this is output at IC34/pin3. Switching the
    front panel EG MODE switch back and forth should toggle the voltage
    between 0 and +5V (ca). If not the culprit might be IC34 or on the
    KLM-370 front panel or the cabling between KLM-377/KLM-370/KLM-366.

    Be aware that other patch settings (such as Cutoff Freq, Resonance)
    may cause the ADSR effect less audible. I suggest that you use a
    setting with the filter all the way open and no resonance and the
    EG setting at center position ("0").

I hope this helps,

Johannews



On 11.02.2014 20:11, victoranalo32@yahoo.es wrote:
>
>
> Hey guys, I found this site and I think fabulous,
> first thank any aid,
>
> I have a P6, I'm repairing but has 2 faults.
> First ruling in manual mode (ADSR) always sounds like gate, I think the
> switch does not work and does not reach the order,
>
> Second failure, I do not work the depth of pwm Speed.
> Greetings to all and thanks.
>
>
> 
>
>

>
> Hello, I've been trying to find out about Speed \u200b\u200bPmw, now, in the output
> of operational ic 13, I see the change in line with the oscilloscope.
> Also at the base of Q2, D1 .. It seems that up here is good, do not you
> think?
>
> About the other problem, which does not work ADSR, is a problem in the EG
> switch, there are some presets that work with release, but other preset
> have no adsr, that does not work well for commutation, I looked, and belongs
> to do2 I've looked and I see a sign with my oscilloscope, and continuity
> with other ics ...
>