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PolySix only works in test mode?

PolySix only works in test mode?

2019-04-23 by joeyvfx@gmail.com

Hi there! I tried searching around to see if anyone else had this issue but I can't seem to find anything. I got a polysix with the typical battery leak, so I ordered a replacement PCB from here. The build went fine, but i'm finding that the polysix only works properly when SW1 on KLM-367a (the test mode switch) is switched to test mode.

I haven't actually calibrated it yet, I just matched the pot values from the original board. When it's in test mode, everything seems to work normally, which is good. Is it bad to use the polysix in test mode? Do I need to calibrate something more precisely? Or is it okay to keep it in test mode?

Re: PolySix only works in test mode?

2019-04-23 by ciolac@pragmatrax.com

Hi,

Have you fixed the PCB bugs listed?
https://sites.google.com/site/jedjorgensen/klm367a/images/pcb-bugs-errors
The test mode is used for the D/A adjustment, see the service manual/8 Adjustment Procedure/3 KLM-367 check and adjustment/(2) D/A adjustment.
The schematics show the test switch being checked by the CPU for a low on P16 (pin 31). When P16 senses a low level, the CPU will run the test sequence for D/A adjustment, and display the test values on the program leds. So, it’s not right to run the board in test mode and expect normal operation.
I have not seen the PCB you purchased, but since it works in test mode, although it should not, it’s most likely that the PCB markings for the switch positions could be wrong, On the original board, in normal operation the switch is towards the CPU.

Best,
Alec

Re: [PolySix] PolySix only works in test mode?

2019-04-23 by Bob Grieb

There is no way that the MCU is in test mode if the Poly6 is operating normally.
If the switch has only two pins on it, and you installed it the wrong way around
on the board, then the positions would not match the markings on the board.

Re: PolySix only works in test mode?

2019-04-23 by joeyvfx@gmail.com

I have fixed the PCB bugs listed on the website, I even tried both capacitors on C23. No change in behavior. 

Pictures of the PCB I have are here. I'm totally sure that I installed the switch correctly, it's on the component side with everything else. I didn't use the switch recommended on Jed's website, instead I got one of these switches, but from what I can tell they're electrically the same.

Another thing that I noticed is if I start the polysix in test mode, I can switch it back to normal mode once it's on and it still works normally. It's almost like the switch has no effect. However, if I start the polysix switched to normal mode, it does not work, and if I try to switch it to test mode while it's still on, it still doesn't work.

Re: [PolySix] Re: PolySix only works in test mode?

2019-04-23 by <backshall1@bellsouth.net>

Yup, it still sounds like the switch is in backwards. Not really a problem, as long as you know “normal” is the other direction.
Don B.
 
Sent: Tuesday, April 23, 2019 2:29 PM
Subject: [PolySix] Re: PolySix only works in test mode?
 
 

I have fixed the PCB bugs listed on the website, I even tried both capacitors on C23. No change in behavior.

Pictures of the PCB I have are here. I'm totally sure that I installed the switch correctly, it's on the component side with everything else. I didn't use the switch recommended on Jed's website, instead I got one of these switches, but from what I can tell they're electrically the same.


Another thing that I noticed is if I start the polysix in test mode, I can switch it back to normal mode once it's on and it still works normally. It's almost like the switch has no effect. However, if I start the polysix switched to normal mode, it does not work, and if I try to switch it to test mode while it's still on, it still doesn't work.

Re: PolySix only works in test mode?

2019-04-23 by joeyvfx@gmail.com

That is odd. Is there anyone else here who is using one of Jed's and Andrew's PCB replacements? I'd like to know if other peoples boards act the same way as mine with the switch. How odd! I appreciate the help, thank you all for responding.

Re: [PolySix] Re: PolySix only works in test mode?

2019-04-23 by <backshall1@bellsouth.net>

I’ve built many of these boards. When the switch is on, it is in test mode. For the switch you used, no doubt it looks upside down when it is installed properly.
 
Sent: Tuesday, April 23, 2019 4:11 PM
Subject: [PolySix] Re: PolySix only works in test mode?
 
 

That is odd. Is there anyone else here who is using one of Jed's and Andrew's PCB replacements? I'd like to know if other peoples boards act the same way as mine with the switch. How odd! I appreciate the help, thank you all for responding.

Re: [PolySix] Re: PolySix only works in test mode?

2019-04-23 by <backshall1@bellsouth.net>

Yes, Test is On, so you could flip it around and it would be correct.
Don B.
 
Sent: Tuesday, April 23, 2019 4:41 PM
Subject: Re: [PolySix] Re: PolySix only works in test mode?
 
 

Interesting. Just for clarity, here's a picture of the switch installed on the board. I assumed these switches didn't have to be installed in a specific direction... so I could potentially resolder the switch flipped the other way, and then it would be labeled correctly?

Re: [PolySix] Re: PolySix only works in test mode?

2019-04-23 by <backshall1@bellsouth.net>

And if everything seems to be functioning properly with the switch off, then congratulations on a successful board build. The uncalibrated settings must be reasonable enough to not cause any major problems, but you should really go through the calibration steps for the board.
 
Sent: Tuesday, April 23, 2019 5:08 PM
Subject: Re: [PolySix] Re: PolySix only works in test mode?
 
 

Yes, Test is On, so you could flip it around and it would be correct.
Don B.
 
Sent: Tuesday, April 23, 2019 4:41 PM
Subject: Re: [PolySix] Re: PolySix only works in test mode?
 
 

Interesting. Just for clarity, here's a picture of the switch installed on the board. I assumed these switches didn't have to be installed in a specific direction... so I could potentially resolder the switch flipped the other way, and then it would be labeled correctly?

Re: [PolySix] Re: PolySix only works in test mode?

2019-04-24 by joeyvfx@gmail.com

Thank you! Yes, i'm really glad that it's working this well right off the bat. I don't own an oscilloscope so it might be a while until I can calibrate it if I do it on my own. How crucial is it to calibrate the polysix?

The only things i've noticed are the attack, decay, and release knobs only really responding in the VCA when turned about halfway up, which could be normal behavior for all I know. There's still a good range from 5-10, and the filter still seems responsive at levels below 5. The only other issue besides that is that the resonances on the filters aren't perfectly tuned when using key tracking. Nothing too major.

Re: [PolySix] Re: PolySix only works in test mode?

2019-04-24 by <backshall1@bellsouth.net>

 
The D/A Adjustment is the most critical to getting all knob ranges correct. If the thing boots up properly every time, then the Reset circuit adjustment is probably okay. The filter tracking is all done on the KLM-366 and you need to get the KLM-367 calibrated first.
They only list 4 items for KLM-367 check and adjustment:
(1) Reset circuit
(2) D/A adjustment
(3) MG adjustment
(4) PW/PWM check and adjustment
 
I should mention two important things. Correct +/-5V and +/-15V supplies need to be set first. If you tweak these later, you may have to recalibrate everything else. That picture of the “Normal setting” is important. Make sure all knobs and switches are set just like the picture before attempting the D/A adjustment or anywhere else in the service manual where they tell you to start with the normal setting.
 
Don B.
 
Sent: Wednesday, April 24, 2019 1:09 AM
Subject: Re: [PolySix] Re: PolySix only works in test mode?
 
 

Thank you! Yes, i'm really glad that it's working this well right off the bat. I don't own an oscilloscope so it might be a while until I can calibrate it if I do it on my own. How crucial is it to calibrate the polysix?

The only things i've noticed are the attack, decay, and release knobs only really responding in the VCA when turned about halfway up, which could be normal behavior for all I know. There's still a good range from 5-10, and the filter still seems responsive at levels below 5. The only other issue besides that is that the resonances on the filters aren't perfectly tuned when using key tracking. Nothing too major.

Re: [PolySix] Re: PolySix only works in test mode?

2019-04-24 by <backshall1@bellsouth.net>

A couple more things. You don’t need an oscilloscope for the D/A adjustment. It’s just a lot of finicky turns of VR6 and VR7 and watching the Program LEDs. For the MG and PWM, you can probably just set their ranges to your own personal preferences without an oscilloscope. If it sounds good to you and you are the only one playing it, why not? For PW VR3 adjustment, the objective is to get the pulse width down to zero when the knob is at 10. As you turn up the PW knob, the pulse will get thinner and thinner until the note you are playing is no longer audible. This is used in some patches to “turn off” the oscillators so only the filter resonance and sub-oscillator can be heard.
Don B.
 
Sent: Wednesday, April 24, 2019 8:09 AM
Subject: Re: [PolySix] Re: PolySix only works in test mode?
 
 

 
The D/A Adjustment is the most critical to getting all knob ranges correct. If the thing boots up properly every time, then the Reset circuit adjustment is probably okay. The filter tracking is all done on the KLM-366 and you need to get the KLM-367 calibrated first.
They only list 4 items for KLM-367 check and adjustment:
(1) Reset circuit
(2) D/A adjustment
(3) MG adjustment
(4) PW/PWM check and adjustment
 
I should mention two important things. Correct +/-5V and +/-15V supplies need to be set first. If you tweak these later, you may have to recalibrate everything else. That picture of the “Normal setting” is important. Make sure all knobs and switches are set just like the picture before attempting the D/A adjustment or anywhere else in the service manual where they tell you to start with the normal setting.
 
Don B.
 
Sent: Wednesday, April 24, 2019 1:09 AM
Subject: Re: [PolySix] Re: PolySix only works in test mode?
 
 

Thank you! Yes, i'm really glad that it's working this well right off the bat. I don't own an oscilloscope so it might be a while until I can calibrate it if I do it on my own. How crucial is it to calibrate the polysix?

The only things i've noticed are the attack, decay, and release knobs only really responding in the VCA when turned about halfway up, which could be normal behavior for all I know. There's still a good range from 5-10, and the filter still seems responsive at levels below 5. The only other issue besides that is that the resonances on the filters aren't perfectly tuned when using key tracking. Nothing too major.

Arpeggiator and Keybed not working

2019-04-24 by Barry London

Hi there,
So I’m just diving into this Polysix repair, the 367 was shot so I ordered a https://synthronics.de/klm-367a-replacement/ and swapped out the 8048C-345 and hooked it up but no activity from the keyboard or the arpeggiator.  When I click through the memory banks I’m definitely hearing changes in fx or in LFO rates, and the filter is working, so I’m thinking it’s something on the 366 board, but figured I’d ask here if anyone had any recommendations on what to zone into first.  I also have a working polysix at my home so was thinking about swapping out the 8048C-217 and see if it’s just a bad chip.  Anyway any help is always appreciated.
Thanks so much,
Barry

Re: [PolySix] Arpeggiator and Keybed not working

2019-04-24 by <backshall1@bellsouth.net>

How about swapping the entire keybed first. That’s easy. Are any of the voice LEDs lighting up when you press keys?
Don B.
 
Sent: Wednesday, April 24, 2019 8:39 AM
Subject: [PolySix] Arpeggiator and Keybed not working
 
 

Hi there,

So I’m just diving into this Polysix repair, the 367 was shot so I ordered a https://synthronics.de/klm-367a-replacement/ and swapped out the 8048C-345 and hooked it up but no activity from the keyboard or the arpeggiator.  When I click through the memory banks I’m definitely hearing changes in fx or in LFO rates, and the filter is working, so I’m thinking it’s something on the 366 board, but figured I’d ask here if anyone had any recommendations on what to zone into first.  I also have a working polysix at my home so was thinking about swapping out the 8048C-217 and see if it’s just a bad chip.  Anyway any help is always appreciated.
Thanks so much,
Barry

Re: [PolySix] Arpeggiator and Keybed not working

2019-04-24 by Florian Anwander

Are you sure that you connected the cable from the keyboard to the
KLM366 in the right orientation?


Am 24.04.2019 um 14:39 schrieb Barry London eveready9v@hotmail.com
[PolySix]:
>
> Hi there,
>
> So I’m just diving into this Polysix repair, the 367 was shot so I
> ordered a https://synthronics.de/klm-367a-replacement/%c2%a0and swapped out
> the 8048C-345 and hooked it up but no activity from the keyboard or
> the arpeggiator.  When I click through the memory banks I’m definitely
> hearing changes in fx or in LFO rates, and the filter is working, so
> I’m thinking it’s something on the 366 board, but figured I’d ask here
> if anyone had any recommendations on what to zone into first.  I also
> have a working polysix at my home so was thinking about swapping out
> the 8048C-217 and see if it’s just a bad chip.  Anyway any help is
> always appreciated.
> Thanks so much,
> Barry

--
http://www.florian-anwander.de

Re: [PolySix] Arpeggiator and Keybed not working

2019-04-24 by Barry London

Yeah, I checked it, at least from the 366 side, but I haven’t had the chance to dive back in since I put it all back together, I need an afternoon to take it all apart again and check the keyboard side of the connector.
Thanks 
Barry

Sent from my cracked iPhone

On Apr 24, 2019, at 9:35 AM, Florian Anwander fanwander@mnet-online.de [PolySix] <PolySix@yahoogroups.com> wrote:

 

Are you sure that you connected the cable from the keyboard to the
KLM366 in the right orientation?

Am 24.04.2019 um 14:39 schrieb Barry London eveready9v@hotmail.com
[PolySix]:
>
> Hi there,
>
> So I’m just diving into this Polysix repair, the 367 was shot so I
> ordered a https://synthronics.de/klm-367a-replacement/ and swapped out
> the 8048C-345 and hooked it up but no activity from the keyboard or
> the arpeggiator.  When I click through the memory banks I’m definitely
> hearing changes in fx or in LFO rates, and the filter is working, so
> I’m thinking it’s something on the 366 board, but figured I’d ask here
> if anyone had any recommendations on what to zone into first.  I also
> have a working polysix at my home so was thinking about swapping out
> the 8048C-217 and see if it’s just a bad chip.  Anyway any help is
> always appreciated.
> Thanks so much,
> Barry

--
http://www.florian-anwander.de

Re: [PolySix] Re: PolySix only works in test mode?

2019-04-25 by joeyvfx@gmail.com

This was very helpful! I managed to adjust the voltages, pulse width, D/A, and I tuned the resonances and tracking of the voices. Things are sounding good! Thank you for your help, I really appreciate it. The only other tiny issue is that I have to keep the tuning knob on the front turned to the 8-9 o'clock position pretty much at all times... is there an internal global tuning offset? I don't see one labeled, only the mid and D#4-E4 pots.

Re: [PolySix] Re: PolySix only works in test mode?

2019-04-25 by <backshall1@bellsouth.net>

The MID should be able to change the global offset without changing the rest of the tuning.
 
Sent: Thursday, April 25, 2019 2:11 AM
Subject: Re: [PolySix] Re: PolySix only works in test mode?
 
 

This was very helpful! I managed to adjust the voltages, pulse width, D/A, and I tuned the resonances and tracking of the voices. Things are sounding good! Thank you for your help, I really appreciate it. The only other tiny issue is that I have to keep the tuning knob on the front turned to the 8-9 o'clock position pretty much at all times... is there an internal global tuning offset? I don't see one labeled, only the mid and D#4-E4 pots.

Re: PolySix only works in test mode?

2019-04-26 by joeyvfx@gmail.com

Hmm... for me the mid pot isn't an offset, it just skews everything out of tune. I might just have to retune the individual voices if I want the main tuning pot on the front to be centered... i'll save that for a rainy day.

Re: [PolySix] Arpeggiator and Keybed not working

2019-04-27 by Barry London

So I pulled the key assigner, the NEC8049C 217 out of my working Polysix and popped it into the one that wasn't working and it works, sooooo now I've got to source a NEC8049C 217.  Anyone got any leads?
Thanks
Barry
From: PolySix@yahoogroups.com <PolySix@yahoogroups.com> on behalf of Florian Anwander fanwander@mnet-online.de [PolySix] <PolySix@yahoogroups.com>
Sent: Wednesday, April 24, 2019 9:34 AM
To: PolySix@yahoogroups.com
Subject: Re: [PolySix] Arpeggiator and Keybed not working
 
 

Are you sure that you connected the cable from the keyboard to the
KLM366 in the right orientation?

Am 24.04.2019 um 14:39 schrieb Barry London eveready9v@hotmail.com
[PolySix]:

>
> Hi there,
>
> So I’m just diving into this Polysix repair, the 367 was shot so I
> ordered a https://synthronics.de/klm-367a-replacement/ and swapped out
> the 8048C-345 and hooked it up but no activity from the keyboard or
> the arpeggiator.  When I click through the memory banks I’m definitely
> hearing changes in fx or in LFO rates, and the filter is working, so
> I’m thinking it’s something on the 366 board, but figured I’d ask here
> if anyone had any recommendations on what to zone into first.  I also
> have a working polysix at my home so was thinking about swapping out
> the 8048C-217 and see if it’s just a bad chip.  Anyway any help is
> always appreciated.
> Thanks so much,
> Barry

--
http://www.florian-anwander.de

Re: [PolySix] Arpeggiator and Keybed not working

2019-04-27 by <backshall1@bellsouth.net>

Ebay seller ”moogchild” has one for $59 in Spain. If you have to get one burned, there are some new ones if you can find somebody with the binary file and a ROM burner. The 4789 is a slightly newer EPROM version of the same chip if someone has a programmer that can do EPROM but not ROM.
 
Don Backshall
 
Sent: Saturday, April 27, 2019 2:34 PM
Subject: Re: [PolySix] Arpeggiator and Keybed not working
 
 

So I pulled the key assigner, the NEC8049C 217 out of my working Polysix and popped it into the one that wasn't working and it works, sooooo now I've got to source a NEC8049C 217.  Anyone got any leads?
Thanks
Barry
From: PolySix@yahoogroups.com <PolySix@yahoogroups.com> on behalf of Florian Anwander fanwander@mnet-online.de [PolySix] <PolySix@yahoogroups.com>
Sent: Wednesday, April 24, 2019 9:34 AM
To: PolySix@yahoogroups.com
Subject: Re: [PolySix] Arpeggiator and Keybed not working
 
 

Are you sure that you connected the cable from the keyboard to the
KLM366 in the right orientation?

Am 24.04.2019 um 14:39 schrieb Barry London eveready9v@hotmail.com
[PolySix]:

>
> Hi there,
>
>
So I’m just diving into this Polysix repair, the 367 was shot so I
>
ordered a https://synthronics.de/klm-367a-replacement/ and swapped out
>
the 8048C-345 and hooked it up but no activity from the keyboard or
> the
arpeggiator.  When I click through the memory banks I’m definitely
>
hearing changes in fx or in LFO rates, and the filter is working, so
>
I’m thinking it’s something on the 366 board, but figured I’d ask here
>
if anyone had any recommendations on what to zone into first.  I also
> have a working polysix at my home so was thinking about swapping out
> the 8048C-217 and see if it’s just a bad chip.  Anyway any help is
> always appreciated.
> Thanks so much,
> Barry

--
http://www.florian-anwander.de

Re: [PolySix] Arpeggiator and Keybed not working

2019-04-27 by <backshall1@bellsouth.net>

Totally forgot about Bob’s replacement for the 8049 at http://www.tauntek.com/PolySix.htm. You’re in the US aren’t you Bob?
Don B.
 
Sent: Saturday, April 27, 2019 3:11 PM
Subject: Re: [PolySix] Arpeggiator and Keybed not working
 
 

You could use the one that I designed, which would also give you note on/off MIDI.

Bob Grieb (Tauntek.com)

Re: [PolySix] Arpeggiator and Keybed not working

2019-04-29 by Barry London

Hey Bob, 
I’ll reach out to you via regular email as to not bore anyone on this thread.
Thanks
Barry

Sent from my cracked iPhone

On Apr 28, 2019, at 7:58 PM, Bob Grieb bobgrieb@yahoo.com [PolySix] <PolySix@yahoogroups.com> wrote:

 

Yes. On the East Coast.

Bob

--------------------------------------------
On Sat, 4/27/19, backshall1@bellsouth.net [PolySix] <PolySix@yahoogroups..com> wrote:

Subject: Re: [PolySix] Arpeggiator and Keybed not working
To: PolySix@yahoogroups.com
Date: Saturday, April 27, 2019, 4:10 PM


Totally forgot about Bob’s replacement for the 8049
at http://www.tauntek.com/PolySix.htm.

You’re in the US aren’t you Bob?
Don B.

Re: [PolySix] Arpeggiator and Keybed not working

2019-04-30 by Barry London

In looking for a replacement Key Assigner NEC D8049C-217 I’ve come across a few that were listed  for Monopoly’s and or Poly61’s, are they all interchangeable?
Thanks
Barry

Sent from my cracked iPhone

On Apr 29, 2019, at 2:08 PM, Barry London eveready9v@hotmail.com [PolySix] <PolySix@yahoogroups.com> wrote:

 

Hey Bob, 

I’ll reach out to you via regular email as to not bore anyone on this thread.
Thanks
Barry

Sent from my cracked iPhone

On Apr 28, 2019, at 7:58 PM, Bob Grieb bobgrieb@yahoo.com [PolySix] <PolySix@yahoogroups.com> wrote:

 

Yes. On the East Coast.

Bob

--------------------------------------------
On Sat, 4/27/19, backshall1@bellsouth.net [PolySix] <PolySix@yahoogroups..com> wrote:

Subject: Re: [PolySix] Arpeggiator and Keybed not working
To: PolySix@yahoogroups.com
Date: Saturday, April 27, 2019, 4:10 PM


Totally forgot about Bob’s replacement for the 8049
at http://www.tauntek.com/PolySix.htm.

You’re in the US aren’t you Bob?
Don B.

Re: [PolySix] Arpeggiator and Keybed not working

2019-04-30 by <backshall1@bellsouth.net>

The MonoPoly can’t be, since it is a 4 VCO machine. The Poly-61 might be? I know I’ve seen them listed on Ebay as being for both synths, but the seller might not know anything about the mask ROM being onboard and might just think it is a generic microcontroller.
Don B.
 
Sent: Tuesday, April 30, 2019 4:16 PM
Subject: Re: [PolySix] Arpeggiator and Keybed not working
 
 

In looking for a replacement Key Assigner NEC D8049C-217 I’ve come across a few that were listed  for Monopoly’s and or Poly61’s, are they all interchangeable?

Thanks
Barry

Sent from my cracked iPhone

On Apr 29, 2019, at 2:08 PM, Barry London eveready9v@hotmail.com [PolySix] <PolySix@yahoogroups.com> wrote:

 

Hey Bob, 

I’ll reach out to you via regular email as to not bore anyone on this thread.
Thanks
Barry

Sent from my cracked iPhone

On Apr 28, 2019, at 7:58 PM, Bob Grieb bobgrieb@yahoo.com [PolySix] <PolySix@yahoogroups.com> wrote:

 

Yes. On the East Coast.

Bob

--------------------------------------------
On Sat, 4/27/19, backshall1@bellsouth.net [PolySix] <PolySix@yahoogroups..com> wrote:

Subject: Re: [PolySix] Arpeggiator and Keybed not working
To: PolySix@yahoogroups.com
Date: Saturday, April 27, 2019, 4:10 PM


Totally forgot about Bob’s replacement for the 8049
at http://www.tauntek.com/PolySix.htm.

You’re in the US aren’t you Bob?
Don B.

Re: [PolySix] Arpeggiator and Keybed not working

2019-05-02 by Bob Grieb

You need to check the ROM code version. I think it should be 214 (not 100% sure). that number is on the chip.

The Mono/Poly has an extra diode on the pcb that the code checks for and if it sees it,
it behaves differently. So some Monopoly's used the same MCU as the PolySix,
in fact my Monopoly is currently running with the MCU that I removed from my PolySix
after installing my replacement MCU design.

Bob

Re: [PolySix] Arpeggiator and Keybed not working

2019-05-03 by Barry London

Ok, so to add to the general weirdness of this,  I called the guys at the local synth repair shop and asked if they had a spare Polysix D8049C-217 living around, and the said they could burn me one, I head over, they've got it working in a Polysix at the shop, it works there.  I get home pop it into the repair Polysix, all the LED’s light up in the Keyboard assign panel but nothing works.   I pop the working D8049C-217 out of my working Polysix, put it into the repair Polysix, and the repair Polysix works(still needs some TLC, but keys are making sounds in a sort of relatively 12 tone scale).  I take your burnt chip from the shop  and put it in my Polysix and it works in mine, but not the repair unit.   Serial  # wise they’re really close #465506 & #465214. Anyone got a clue what that could possibly mean?
Barry

Sent from my cracked iPhone

On May 1, 2019, at 8:13 PM, Bob Grieb bobgrieb@yahoo.com [PolySix] <PolySix@yahoogroups.com> wrote:

 

You need to check the ROM code version. I think it should be 214 (not 100% sure). that number is on the chip.

The Mono/Poly has an extra diode on the pcb that the code checks for and if it sees it,
it behaves differently. So some Monopoly's used the same MCU as the PolySix,
in fact my Monopoly is currently running with the MCU that I removed from my PolySix
after installing my replacement MCU design.

Bob

Re: [PolySix] Arpeggiator and Keybed not working

2019-05-03 by Bob Grieb

Possibly the oscillator was not running when it didn't work.
Different chips are a little different in that area, as it's really an
analog function, so component tolerances can make a difference.
Just an idea...

I wonder if the +5V is adjusted the same in your unit and the other one.
If it's a little lower, that could affect the oscillator start-up as well.

Bob