Polysix Rebuild

[The Elf]

Sounds like there's hope. It will be interesting to follow your progress!

[nickle15]

So we finally got into the keyboard parts last night - just to give them a look. I haven't photographed anything yet but will do that once we unpack them for good.

KLM-367 (if I'm looking at everything correctly) is the board that is susceptible to damage from the battery leakage and it appears this one is no exception. We could see where attempts have been made to fix some traces. Time will tell if those attempts were successful. If not I suppose the Kiwisix upgrade would be the next solution since that apparently replaces this entire board (again, if I'm understanding everything correctly) but I will wait on that as it's a significant outlay of cash.

According to the original description I need to replace three switches - one is broken and two are damaged. And we need to replace two chips - one is $5 and one is $100.

All of the buttons are there except for one. Unfortunately not a single knob came bundled with the parts. The seller said he thought he had a bunch of them in his shop somewhere so I'll touch base with him on those because if you're actually lucky enough to find them they're annoyingly expensive. I'm sure there are other knobs that would fit and do the trick but I'd like to bring it back to stock as much as possible.

Also missing is the part of the chassis that houses the pitch and mod wheels - and those wheels are missing as well.

So basically I didn't learn much more by looking at the parts but after several weeks it looks like we're getting ready to ramp it up and that's exciting!

As posted elsewhere in the keyboard forum here we are also tackling a Prophet 600 that is in fantastic condition, besides a series of 8 keys that won't work. So - not sure what gets done first or how quickly, but fingers crossed we have some success with both keyboards.

I'll post more soon!

[Dan LB]

Not sure where you are in the world nickle15 but if you’re in the US, it might be worth contacting Syntaur to help you locate the missing parts you need.

https://www.syntaur.com/

[nickle15]

Not sure where you are in the world nickle15 but if you’re in the US, it might be worth contacting Syntaur to help you locate the missing parts you need.

https://www.syntaur.com/

Thanks Dan. I'm in the US and monitor the Syntaur site regularly. They seem like a really decent outfit and they're definitely on my radar. I appreciate the tip!

[BJG145]

one is $100

...what's that...?

[nickle15]

one is $100

...what's that...?

Sorry - I was just going off some notes my dad had written on a diagram. But it looks like the SSM2044.

[Folderol]

Interesting chip. It wouldn't be easy to emulate that!

[BJG145]

it looks like the SSM2044

I wondered if it might be. It's possible I might have one; I'll check.

[nickle15]

it looks like the SSM2044

I wondered if it might be. It's possible I might have one; I'll check.

Very cool - thanks!

[Dan LB]

........it looks like the SSM2044.

There’s somebody local to me selling two of these chips. He wants €45 each for them. If you get stuck and can’t find them in the US I’d be happy to pick one up for you and post it.

[nickle15]

........it looks like the SSM2044.

There’s somebody local to me selling two of these chips. He wants €45 each for them. If you get stuck and can’t find them in the US I’d be happy to pick one up for you and post it.

Awesome offer and I'll let you know - thanks so much!!

[nickle15]

At long last we were able to lay out all the parts. Here's what we know we're missing:

1 voice chip
Microcontroller
1 7 pin wiring harness
Pitch/mod wheel assembly
Wooden chassis case
All the knobs
One button

Dad started his work on the transformer and planned to work from board to board just trying to get a sense of what might need to be fixed. He didn't get very far - the transformer is bad. So that's where we stand as of this morning. I'm going to get started on pricing the replacement parts we need, starting with the transformer.

[Folderol]

Best of luck with this.
I suggest you check on availability of the processor and the voice chip before spending too much.

[nickle15]

Best of luck with this.
I suggest you check on availability of the processor and the voice chip before spending too much.

Thanks!

Yes I plan to compile a list to see how much it will cost to get the known issues fixed. It's very possible that the cost of the parts would outweigh just buying a functional keyboard.

[jjlonbass]

Which microcontroller is missing? There are 2 - one, a 8049, is the "key assigner" and the other, a 8048, is the "programmer".
Both are mask programmed i.e. the software is hard-wired into the chip - there is no separate PROM. This means that you need the exact correct 8049 or 8048 part containing the correct software. Any old 8049 or 8048 won't work.
I suspect that these will be very difficult to find.

John

[nickle15]

Which microcontroller is missing? There are 2 - one, a 8049, is the "key assigner" and the other, a 8048, is the "programmer".
Both are mask programmed i.e. the software is hard-wired into the chip - there is no separate PROM. This means that you need the exact correct 8049 or 8048 part containing the correct software. Any old 8049 or 8048 won't work.
I suspect that these will be very difficult to find.

John

It's the 8049 that's missing. I was suspicious of how easy it was to find one - but now I know why. Again - your advice/direction is very helpful!

[rockydennis]

It's the 8049 that's missing. I was suspicious of how easy it was to find one - but now I know why. Again - your advice/direction is very helpful!

Taking a quick look online, I do see one site selling the 8049 for the Polysix for 30 Euros.

Here's a site with firmware code for various synths available for free, including the Polysix. I'm guessing the 8748 and 8749 which have eprom and are programmable, and are from the same family can be substituted for the 8048 and 8049 but don't quote me on that.
https://dbwbp.com/index.php/9-misc/37-synth-eprom-dumps

Here's someone replacing the 8049 for the Polysix with Arduino with the code made available.
http://synthhacker.blogspot.com/2013/03/polysix-replacing-8049-key-assigner.html

[nickle15]

It's the 8049 that's missing. I was suspicious of how easy it was to find one - but now I know why. Again - your advice/direction is very helpful!

Taking a quick look online, I do see one site selling the 8049 for the Polysix for 30 Euros.

Here's a site with firmware code for various synths available for free, including the Polysix. I'm guessing the 8748 and 8749 which have eprom and are programmable, and are from the same family can be substituted for the 8048 and 8049 but don't quote me on that.
https://dbwbp.com/index.php/9-misc/37-synth-eprom-dumps

Here's someone replacing the 8049 for the Polysix with Arduino with the code made available.
http://synthhacker.blogspot.com/2013/03/polysix-replacing-8049-key-assigner.html

Excellent - thanks for adding this guidance!

[Drew Stephenson]

The level of expert knowledge that is freely given on this site never ceases to amaze me.

[nickle15]

The level of expert knowledge that is freely given on this site never ceases to amaze me.

Amen!

[rockydennis]

Maybe replacing the 8049 with Arduino is the way to go -
"As many of you know, I made some pretty substantial modifications to my Korg Polysix. One of the biggest changes was to replace the keybed to enable aftertouch. To make this happen, I had to replace the Polysix's Key Assigner with an Arduino. It was a lot of work, but once I made the core hardware modifications, I found that I was able to add lots of features to the Polysix, such as: aftertouch and portamento, more interesting detuning for unison mode, a poly-unison mode, a Moog-like single-trigger mode, and a sustain pedal. All of these modifications were effected through software changes on the Arduino."
http://synthhacker.blogspot.com/2014/03/polysix-sharing-my-arduino-code.html

[BJG145]

That's hardcore. Respect.

[Folderol]

I'd like to know how the guy got hold of a Fatar poly aftertouch keybed.
Oh, and did he have to remortgage the house.

[The Elf]

I'd like to know how the guy got hold of a Fatar poly aftertouch keybed.
Oh, and did he have to remortgage the house.

I've often been told that they don't do one!