Archive of the former Yahoo!Groups mailing list: Discussion about the Korg PolySix synthesizer

johannes, check mail..;)

--- In PolySix@yahoogroups.com, Johannes Hausensteiner <johau@...> wrote:
>
> Hi,
>
> I am afraid I cannot help you with the noise remotely. The Polysix is
> quite noisy. Most of it comes from the BBD circuits of the KLM-368
> board. You might take the signal directly from CN14 of KLM-366. This
> is the pure synthesizer signal, before going through the KLM-368
> effects board.
>
> ARP:
> It might be that ARP On/Off button does not work. You could try with
> the lid open to make a temporary short across the button contacts
> with a pair of pliers or a wire. These buttons wear out.
>
> Good luck!
>
> Johannes
>
>
> On 2012-12-05 18:57, Arp Duex wrote:
> > see comments.
> >
> >
> > ________________________________
> > From: Johannes Hausensteiner <johau@...>
> > To: PolySix@yahoogroups.com
> > Sent: Wednesday, December 5, 2012 7:24 PM
> > Subject: Re: [PolySix] Re: klm 367 board
> >
> >
> >
> > Hi,
> >
> > 1) Noise:
> > - Does the noise change after you play (a) key(s)?
> > - I have seen somewhere instructions for making an electric shield
> > between the KLM-368 and KLM-369 boards. Maybe this woiuld help.
> >
> >
> > //nope.. noise is there.. disapearing and reapearing in no regular
> > fashion. at least i could determine any pattern.
> >
> > 2) Arpeggiator:
> > - How does it behave when you are saying "it is dead"?
> > - Does the ARP On/Off button LED work as expected?
> > - Does the LED flash according to the speed setting?
> > - The ARP trigger signal is routed through the rear panel "ARP Trig In"
> > jack. This is a "normalized" jack, maybe the contacts are dirty; or
> > one of the connections is bad on KLM-366, KLM-371.
> >
> >
> > // led is flashing but when hittin the arp button it remains off.
> > i'll check the jack.
> >
> > Good luck!
> >
> > Johannes
> >
> > On 2012-12-05 15:33, Arp Duex wrote:
> >> Hi,
> >>
> >>
> >> Yes. Found the guidelines for calibrating them. The noise on output puzzles me. Sometimes appear / sometimes disappear for no apparent reason.
> >>
> >> Arpegiator still dead.
> >>
> >>
> >> I will continue the troubleshooting tommrow. Now I need a beer.
> >>
> >>
> >> Thanks guys
> >> Razvan
> >>
> >>
> >>
> >> ________________________________
> >> From: tonezone020 <swamp.gigs@...>
> >> To: PolySix@yahoogroups.com
> >> Sent: Wednesday, December 5, 2012 4:06 PM
> >> Subject: [PolySix] Re: klm 367 board
> >>
> >>
> >>
> >> Hi,
> >>
> >> Guidelines for calibrating each voice are in the service manual...
> >>
> >> T
> >>
> >> --- In PolySix@yahoogroups.com, "arpm234" <arpm234@> wrote:
> >>>
> >>> Hey Johannes,
> >>>
> >>> Thanks a lot for the ideas. I've tested this morning the RESET signal of the main cpu and whatever i did, there were constantly 4.6 v there so by following the schematics I noticed it linked to the comparator IC5, LM393 which was bad in a way that pin 7 (output) and pin 8 (vcc) were internally shorted.
> >>>
> >>> Replaced that and everything came to live. Including keyboard and tones.
> >>>
> >>> NOW, There are still things to figure out.
> >>>
> >>> 1. Arpeggiator not working.
> >>> 2. There is a noise around 22khz at output, like a self resonant thing like an old tube while functioning or like a camera flash when charging. very annoying.
> >>> 3. each and every voice may need calibrating as each one is different in volume, pitch or filter. are there any guidelines for this?
> >>>
> >>> thanks again.
> >>>
> >>> Razvan
> >>>
> >>> --- In PolySix@yahoogroups.com, Johannes Hausensteiner <johau@> wrote:
> >>>>
> >>>> Hi Razvan,
> >>>>
> >>>> I think there are two different problemes:
> >>>> - KLM367 CPU not starting
> >>>> - KLM366 Key Assigner behaving wierd
> >>>>
> >>>> First thing ist to make the KLM-367 CPU start reliable. Check the power
> >>>> supply for correct voltages and perform the reset circuit adjustment
> >>>> procedure given in the service manual.
> >>>> The test pulse at TP4 ∗is∗ in 20msec intervals. The pulse itself is
> >>>> very short.
> >>>> Check the resonator frequency at IC22 (CPU) pin 3. It should be ca 6MHz.
> >>>>
> >>>> Second: The KLM-366 has a test mode as well. "It is started by jumpering
> >>>> pins DB7 and P17 using a diode (cathode towards DB7) on the 8049
> >>>> processor on the KLM-366 circuit board (this can be done on the
> >>>> keyboard connector CN04). In this mode the CV DAC is set to generate
> >>>> 0V, 2.5V, or 5V depending on the position of the OCTAVE switch (16'
> >>>> results in 0V, etc.)".
> >>>> You can check this voltage at KLM366/IC9/pin1.
> >>>> Check the reset signal. KLM-366 is in reset when switching to Tape
> >>>> Interface mode. Check the resonator frequency. It should be like on
> >>>> KLM-367 6MHz at CPU pin 3.
> >>>>
> >>>> Do the buttons behave normally? (Porbably not...)
> >>>> The BANK, MANUAL, and PROGRAM buttons operate on the KLM-367 Programmer
> >>>> CPU, whereas the ARP, HOLD, UNISON, CHORD MEM, and POLY buttons operate
> >>>> on the KLM-366 CPU.
> >>>>
> >>>> Good luck,
> >>>>
> >>>> Johannes
> >>>>
> >>>>
> >>>>
> >>>> On 2012-12-04 20:27, arpm234 wrote:
> >>>>> nobody ?
> >>>>>
> >>>>> --- In PolySix@yahoogroups.com, "arpm234" <arpm234@> wrote:
> >>>>>>
> >>>>>> Hello,
> >>>>>>
> >>>>>> I've did some tests today and here;s what i found:
> >>>>>>
> >>>>>> TO CONFIRM: cpu seems to be working fine since i was able to see the clock on TP4 on osciloscope. Strege thing that somebody mentioned the gap should be 20 ms and i meassured 10ms. Is this ok ? Also the TP2 spot looks ok - The multiplexed signal from the pots it is there.
> >>>>>>
> >>>>>> PROBLEM: there cpu starts randomnly. A few power off - power on cycles are necesary to get the clock there. I this this is related of the bad 4 x 74ls75 found on the control panel board. Two of these latches seem to be dead.
> >>>>>>
> >>>>>> PROBLEM: Altoought there is sound presend, and lfo, cutoff, and all the other pots are working, the sound is non interupted, very loud and at a rather high pitch. voice 6, 5, 4 diode leds are light up, and the sound resemnbles like a few vco beeing active. the other 3 leds, for voice 1, 2, 3 are off. touching the keyboard changes the pitch slighly but then resumes the state before. I'm suspecting the latches: 74ls75
> >>>>>>
> >>>>>> QUESTION: how to test the key assigner cpu ? Is there a method simillar to the uC found on KLM 367 ?
> >>>>>>
> >>>>>> Thanks for support guys.
> >>>>>>
> >>>>>> Razvan
> >>>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
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