Discussion about the Korg PolySix synthesizer

Don,

Sounds a bit like 'Scrapheap Challenge'. If you have that on TV where you
are then you'll know what I mean. BTW. The CPU also has a T1 pin. This is
for clocking the data in from the tape input. So now you know!

Cheers,
Andy


On 27/01/2010 02:28, "backshall1 (dsl)" <backshall1@bellsouth.net> wrote:

>  Andy,
> 
> Change of plans. I just put this KLM-367 in the other Polysix, fired it up,
> and it works! (sort of, sometimes, mostly). The knobs do the right thing,
> and only one thing, but they are so scratchy and intermittent it's hard to
> tell if they are doing anything at all sometimes, and less than half of the
> keys work, and the tuning is way off. Anyway, it looks like your idea about
> the MUX chips on the KLM 369/370 is probably right on the mark. Now, if I
> just use that case, this keyboard, that KLM-369, this KLM-367, that KLM-370,
> this KLM-366..........
> 
> Don B.
> 
> -----Original Message-----
> From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of
> backshall1 (dsl)
> Sent: Tuesday, January 26, 2010 8:15 PM
> To: PolySix@yahoogroups.com
> Subject: RE: [PolySix] Wrong functions controlled by knobs?
> 
> So that's what T0 is for! It shouldn't be too hard to find a decent pair of
> 4051s. I really need to buy some better sockets first though. I've only got
> some really flimsy ones. The 367 and 366 boards each have several Toshiba
> 14051s as well, so I really hope this is not a shelf-life problem with those
> chips. Maybe I'll try to pull the panel boards out of that other Polysix
> first. Too bad the 367 board on that one is about 30% black tracks where
> there should be copper.
>  
> Don B.
> 
>   _____  
> 
> From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of
> Andrew Jury
> Sent: Tuesday, January 26, 2010 6:59 PM
> To: PolySix@yahoogroups.com
> Subject: Re: [PolySix] Wrong functions controlled by knobs?
> 
> 
>   
> 
> Don,
> 
> Welcome to the World of KLM367 troubleshooting!
> 
> Shame the MUX pair aren't socketed as you could switch them around and see
> if, for instance, the VCF cutoff problem moved to the PW/PWM output. As
> these two are just 4000 series CMOS logic and it might be worth taking them
> out, soldering in sockets and replace them with a nice pair of NXT HEF4051s,
> etc. The old ones are almost 30 years old. Doesn't complimentary metal oxide
> have a shelf life?!
> 
> If you are wondering how the analogue data is clocked back into the circuit
> a pulse train appears at the junction of R72 and D10. This is used to
> program the mask ROM on test pin T0. So you should see data here from the
> multiplexor end on the KLM369.
> 
> Cheers,
> Andy
> 
> On 26/01/2010 23:27, "backshall1 (dsl)" <backshall1@bellsout
> <mailto:backshall1%40bellsouth.net> h.net> wrote:
> 
>> This thing is making me crazy. I checked the D00-D07 bus several times
> with
>> a ohmmeter from CN10 to IC 24,26,30,31,33, 28, 29, 34, 35 and can't see a
>> problem. With the oscilloscope, there is a decent signal on every pin of
>> every chip, although I couldn't say if it is correct. Unless there is some
>> crosstalk between data lines somehow, I don't think there's a problem
> here.
>> I found some problems with the schematic:
>> IC24 is mislabelled as IC34,
>> CN10 has two pins labelled D06 and no D07,
>> IC23 shows pins 5 and 6 connected. They are not.
>> 
>> I went back to the panel knobs and checked for -5v to +5v from each of
> them.
>> That looks okay. Then it goes into the MUX, and comes out really messed
> up.
>> As expected, the "Data" line from the MUX chips looks like a set of random
>> analog voltage steps, but each knob does not seem to control just one
> step.
>> The knobs that work change 2 different "steps", the knobs that do nothing
>> also change nothing, and the knobs that are controlling more than one
>> parameter are changing more than 2 steps. It seems some knobs are not
> being
>> read at all and others are being read more than once. Seems like a timing
>> problem with the signals on A,B,C,Inh1 and Inh2. These lines also check
> out
>> okay back to all ICs they are connected to. My old single-trace Heathkit
>> oscilloscope (built it myself) is not up to the task of analyzing relative
>> timings of these signals so I'm looking for a 4 channel scope on Ebay.
>> Just for grins, I popped a different 8048 CPU from another dead Polysix
> into
>> this one. It didn't change any symptoms.
>> 
>> I did some more careful measurements of which knob is changing what, as
> seen
>> on the outputs of ICs 7,9,10,11,12,13,14,16.
>> Effect Speed - does nothing,
>> VCF Cutoff - does nothing,
>> EG Int - does nothing,
>> Res - changes Res and Attack,
>> Attack - does nothing,
>> Decay - changes Decay and Sustain,
>> Sustain - does nothing,
>> Release - OK, 
>> KB Track - OK, 
>> PW/PWM - OK, 
>> PWM Speed - OK, 
>> MG Freq - OK, 
>> MG Delay - changes MG Delay and EG Int,
>> MG Level - changes MG Level and VCF Cutoff.
>> 
>> It's easy to see where the D/A conversion is on IC33, but where does the
> A/D
>> occur? How do knob settings get converted into something that can be
> stored
>> in memory?
>> Thanks,
>> Don B.
>> 
>> _____ 
>> 
>> From: PolySix@yahoogroups <mailto:PolySix%40yahoogroups.com> .com
> [mailto:PolySix@yahoogroups <mailto:PolySix%40yahoogroups.com> .com] On
> Behalf Of
>> Andrew Jury
>> Sent: Sunday, January 17, 2010 9:37 AM
>> To: PolySix@yahoogroups <mailto:PolySix%40yahoogroups.com> .com
>> Subject: Re: [PolySix] Wrong functions controlled by knobs?
>> 
>> 
>> 
>> 
>> Use CN10 as a reference point and make sure DO0-7 connects to every
>> terminating IC which requires access to the data bus. There are plenty of
>> them! When you measure use the metalwork of the connector and the pins of
>> the ICs as your test points, not the solder side. I have seen pads
> connected
>> before which do not connect to the pins themselves. Also, another problem
>> which comes up time after time is hidden battery dielectric leaked under
> the
>> CPU's holder. I generally remove, clean and replace these as a matter of
>> course.
>> 
>> Good luck,
>> Andy
>> 
>> On 17/01/2010 14:19, "backshall1 (dsl)" <backshall1@bellsout
>> <mailto:backshall1%40bellsouth.net> h.net> wrote:
>> 
>>> On the KLM 367 between some specific chips? I started checking resistance
>>> from the 14051s on the panel boards to the processor on the 367 board to
>>> verify A,B,C,INH1,INH2 getting through CN11 okay. It looks good.
>>> Don B.
>>> 
>>> _____ 
>>> 
>>> From: PolySix@yahoogroups <mailto:PolySix%40yahoogroups.com> .com
>> [mailto:PolySix@yahoogroups <mailto:PolySix%40yahoogroups.com> .com] On
>> Behalf Of
>>> Andrew Jury
>>> Sent: Sunday, January 17, 2010 8:10 AM
>>> To: PolySix@yahoogroups <mailto:PolySix%40yahoogroups.com> .com
>>> Subject: Re: [PolySix] Wrong functions controlled by knobs?
>>> 
>>> 
>>> 
>>> 
>>> Ah, sorry Don, I misread that in a hurry, I thought you were setting up
>> the
>>> a/d converter. If only Leds 1-5 light then pay special attention to bits
>> DO5
>>> thru DO7!
>>> 
>>> Let us know how you get on.
>>> 
>>> Andy
>>> 
>>> On 17/01/2010 12:57, "backshall1 (dsl)" <backshall1@bellsout
>>> <mailto:backshall1%40bellsouth.net> h.net> wrote:
>>> 
>>>> Hi Andy,
>>>> I'll check out the data bus and inhibits. No, the calibration did not go
>>>> well. LEDs 1 and 8 are supposed to light up, and I could only get 1 and
>> 5.
>>>> Thanks,
>>>> Don B.
>>>> 
>>>> _____ 
>>>> 
>>>> From: PolySix@yahoogroups <mailto:PolySix%40yahoogroups.com> .com
>>> [mailto:PolySix@yahoogroups <mailto:PolySix%40yahoogroups.com> .com] On
>>> Behalf Of
>>>> Andrew Jury
>>>> Sent: Sunday, January 17, 2010 7:35 AM
>>>> To: PolySix@yahoogroups <mailto:PolySix%40yahoogroups.com> .com
>>>> Subject: Re: [PolySix] Wrong functions controlled by knobs?
>>>> 
>>>> 
>>>> 
>>>> 
>>>> Hi Don,
>>>> 
>>>> You almost certainly have track disconnections. Try and focus in on two
>>>> places of the Œ367. First the data bus DO0-DO7 and the multiplex address
>>> bus
>>>> INH1-3. Using your scope scope ensure that you have at least what look
>>> like
>>>> Œtrains¹ of data pulse when you operate the controls. I find when
> dealing
>>>> with multiple problems like this it pays to select one of the problems
>> and
>>>> focus in on it. Usually everything else will start to become apparent as
>>> you
>>>> make progress. Before you start, however, are you able to perform the
>>> reset
>>>> calibration procedure correctly? If you can verify this then we can
>>> proceed!
>>>> 
>>>> Cheers,
>>>> Andy
>>>> 
>>>> On 16/01/2010 13:56, "longenough2002" <backshall1@bellsout
>>>> <mailto:backshall1%40bellsouth.net> h.net> wrote:
>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> Just got a Polysix in with some bizarre symptoms. It had an old battery
>>>>> in it that looked like it had just started to leak. Only a couple of
>>>>> traces had some black spots and still checked out okay with an
> ohmmeter.
>>>>> I put in a cr2032 and diode and it is saving patches okay. It's not
>>>>> until I twiddle some knobs that things start to get weird. Here is what
>>>>> works: Output, Bend, Tune, VCO, VCA, Arpeggiator, Key Assign,
> Programmer
>>>>> sections all OK. Problem sections: MG, VCF, EG, Effects. By Section: MG
>>>>> - Frequency, Delay and Mod work, but Level seems to be controlling VCF
>>>>> Cutoff, not modulation intensity. VCF - Cutoff does nothing, Resonance
>>>>> works when set between 5 and 10, but seems to control Attack when set
>>>>> between 0 and 5, EG Intensity does nothing, KBD Track works. EG -
> Attack
>>>>> does nothing, Decay works, but in reverse, as if EG Intensity is in the
>>>>> negative range. Release works between 5 and 10 but seems to do nothing
>>>>> between 0 and 5. Effects - switch works, but Intensity does nothing.
>>>>> It would seem the D/A is having serious problems, and I can't get LEDs
> 1
>>>>> and 8 to light up during the reset procedure. I get 1 and 5. I wish the
>>>>> service manual had some voltages to measure, instead of just watching
>>>>> lights. The +/-15 and +/-5v supplies look good. Anybody have ideas
> where
>>>>> to start debugging this? I have a scope and multimeter, but no logic
>>>>> analyzer. Thanks for any assistance you can provide. Don B.
>>>>> 
>>>>> [Non-text portions of this message have been removed]
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>> 
>>>> [Non-text portions of this message have been removed]
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> [Non-text portions of this message have been removed]
>>>> 
>>>> 
>>>> 
>>>> ------------------------------------
>>>> 
>>>> PolySix "Digiest" Page: http://www.acc.
>>> <http://www.acc. <http://www.acc.
> <http://www.acc.umu.se/~amber/Poly6Yahoo> umu.se/~amber/Poly6Yahoo>
>> umu.se/~amber/Poly6Yahoo> umu.se/~amber/Poly6Yahoo! Groups
>>> Links
>>>> 
>>>> 
>>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> [Non-text portions of this message have been removed]
>>> 
>>> 
>>> 
>>> ------------------------------------
>>> 
>>> PolySix "Digiest" Page: http://www.acc.
>> <http://www.acc. <http://www.acc.umu.se/~amber/Poly6Yahoo>
> umu.se/~amber/Poly6Yahoo> umu.se/~amber/Poly6Yahoo! Groups
>> Links
>>> 
>>> 
>>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> [Non-text portions of this message have been removed]
>> 
>> 
>> 
>> ------------------------------------
>> 
>> PolySix "Digiest" Page: http://www.acc.
> <http://www.acc.umu.se/~amber/Poly6Yahoo> umu.se/~amber/Poly6Yahoo! Groups
> Links
>> 
>> 
>> 
> 
> 
> 
> 
> 
> 
> [Non-text portions of this message have been removed]
> 
> 
> 
> ------------------------------------
> 
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6Yahoo! Groups
> Links
> 
> 
> 
> 
> 
> ------------------------------------
> 
> PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6Yahoo! Groups Links
> 
> 
>