Old Korg goodies online

[jh.]

As promised:

I have scanned the most interesting parts of the Korg PE-1000
and put it on my additional schematics page:

http://home.debitel.net/user/jhaible/additional_schemos.html

While I have never heard or played a PE-1000 myself, these
circuits do really impress me. A VCF with basically 2 transistors
and a dual vactrol (the 3rd transistor is just a switch for resonance).
This VCF is shared by all voices.
But wait, there is an additional VCF for each voice (i.e. for
each key). 6dB/Oct only to adjust brightness, but hey, that is
a one(!) transistor filter. Followed by the well known one-transistor
VCA.
Did I mention the one-tyristor-VCO ?
And look how they use one quarter of a 324 for both, buffering
the saw wave, and making a crude form of PWM.

I hope you enjoy it as much as I did!

JH.