Discussion about the Korg PolySix synthesizer

You must be very careful using 2sc or 2sk transistors in place of 2N. The
pins are usually different. EBC on 2N and ECB on 2SC. If you are prepared to
install these with crossed legs, they can be used.

We did notice a problem with the 2N3094 for Q5. On the first note you press,
there is no MG delay when there should be. All subsequent notes have the MG
delayed as they should. If you stop playing for a few seconds, the next note
will not have a delay on the MG. Very strange. We fixed it by reusing the
2SC945 from the old boards. I notice you have a different transistor in Q5.
I guess you will have to try both your old transistor and a 2N3094 to see if
there are any strange delay problems. I haven't heard anything good or bad
about the other transistors. The 2SK30GR should be fine as long as you can
find a pin-out diagram for it, or trace the old board back to see what pin
is connected to what.

 

Don Backshall

 

  _____  

From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of
raisinbag69
Sent: Monday, March 04, 2013 8:33 PM
To: PolySix@yahoogroups.com
Subject: [PolySix] Trannies for Jed's Board

 

  

Ok I'm almost finished my rebuild of battery corroded board using Jed's
replacement. All that is left are transistors to solder in. Following his
BOM it calls for 3904 and 3906 for Q2,4,5. I have plenty of those but was
wondering if reusing the C2785 for q5 and A1175 for Q2,4 would make it work
any better? 

Also, in Q1 on original board, I have a 2sk30GR. Bom says it is supposed to
be a 2N3819. Can I use a 2sk30 on the Jed board for Q1? I have a bunch on
hand OR can use the one on old board. (BOM says try a 2n7000)

I am mostly curious what has worked for other people. it is just as easy for
me to desolder old ones as it is to pop in 390x and a 2sk30.

Thanks





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