Discussion about the Korg PolySix synthesizer

Hello

I think you should ask this on the kiwitechnics maillist (I think you 
are subscribed there).

Florian

Am 27.07.2016 um 16:11 schrieb jesusgallego@gmail.com [PolySix]:
>
> Hi, I'm trying to debug the last remaining problem in my Polysix 
> refurb, it's regarding the LFO signal. The KLM-367 has been replaced 
> with a Kiwisix board successfully and my local tech also did the 369 
> and 371 mods as indicated in the Kiwisix manual, all verified with 
> good continuity.
>
>
> Symptoms:
>
>   * If I set either MG Delay or Speed down to 0 the MG enters a fast
>     LFO state which doesn't respond to speed knob adjustments.
>   * If I set two or more of the parameters entering IC2 in KLM-369 (MG
>     Speed, Delay, Level, PWM Speed) down to 0 it will provoke a
>     program fault and light up all the LEDs in the front panel.
>   * To take it out of program fault I just need to move one or more
>     knobs away from 0.
>   * To bring it out of the unusual fast modulation state I just need
>     force Mod Wheel modulation (which is now carried through the IC2
>     MUX in KLM-369 too, as per Kiwisix modification).
>
> As the fault seems to be affected by many different signals it looks 
> to me like a badly muxed MG signal. IC2 MUX in 369 looks suspect but 
> then I don't understand why it only happens when taking values down to 
> 0 and works perfect when you don't. Muxed signal travels through the 
> purple ribbon cable to Kiwisix which could also be at fault. I can't 
> discard the Kiwisix is doing something wrong interpreting the muxed 
> data but shipping the board back to AU if the fault is somewhere else 
> is overkill. Most recent boot and firmware have also been re-applied 
> to Kiwisix. I haven't seen any possible points of failure in KLM-366 
> as I don't think the problematic signal enters the voice board.
>
> I'd love if someone could help me out with a diagnose before taking 
> any further steps. I don't have a scope to analyze the muxed analog 
> data though.
>
> Thanks in advance.
>