[sdiy] Polysix keys

[Sean Ellis]

Finally the sick polysix arrived today and upon first firing it up it sure 
was acting strange. All of the patch select buttons were constantly lit up, 
the LFO light was not flashing and various other odd things. Strangely 
though all keys work fine, pitch and voice assigning seems to be working 
fine. It's just doing random things though, none of the front panel controls 
work and the settings of the front panel controls seem to randomly change 
sometimes. The arpeggiator and poly, unison switches work fine, as do the 
mod wheel and bender.

I opened it up expecting a furry pile of battery acid and tons of damaged 
traces but I got a surprise:

http://i270.photobucket.com/albums/jj89/Shudder11/missingcpu.jpg

The IC22 cpu is missing! The battery has been removed and there is virtually 
no leakage at all. Also note from the picture the connectors between boards 
have been cut at one stage and carefully resoldered. At some stage a bright 
spark crudely installed a 25 pin d-sub on the back of the polysix although 
its not connected to anything. It's fair to say from the condition of the 
keys (completely covered in filth, lowest C is missing and there are 3 
damaged from what looks like cigarette burns) this synth has seen some 
action in its lifetime :)

I cant complain considering the price I got it for. For the replacement cpu 
I could get the midi upgrade kit that is still available from Johannes 
Hausensteiner but I'm not sure I really need all the extras that are added. 
I was planning a simpler (cheaper) midi retrofit. Does anyone know a source 
for a replacement cpu? Scott Rider says on his page he might be able to help 
but if anyone here has one spare it would be great.



----- Original Message ----- 
From: "Sean Ellis" <tensiontype at hotmail.com>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Monday, January 14, 2008 8:35 PM
Subject: [sdiy] Polysix keys


>I am picking up a sick polysix that is missing a key and has some other 
>unknown problems, probably due to battery leakage. Does anyone know a 
>source for a replacement key?
>
> It's great to have Scott Rider's excellent polysix repair page (here: 
> http://www.oldcrows.net/~oldcrow/synth/korg/polysix/index.html ), looks 
> like I'll be needing it very soon :) Not sure if Scott is on this list but 
> I'm curious about the missing page labeled "Give your Polysix a Korg 
> PS3100-Style Triple resonant filter". Sounds very interesting but the 
> schematics for the Polysix are a nightmare to read.
>
>
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