MS-50 Filter & VCA Schematics Online

[Sean Costello]

Hi all:

Since someone mentioned my web page recently...

I've just posted a new schematic, that for the MS-50 VCF and VCA.  The
filter and VCA both use the CA 3019 diode ring; I would assume that modern
builders could use conventional silicon diodes (perhaps with some matching
involved).  I haven't built the circuit in question, but Romeo Fahl
completed the filter in question, and had this to say:

>Not only that, but I pulled out an aborted attempt at building a Korg MS50
>filter.  I fixed some errors that I found, powered it up, and sure enough
>it worked!  It's a diode ladder design, but it's not a moog/ems/roland
>clone, rather a Sallen and Key filter.  The sound?  It has that sproingy
>resonance found on EMS synths, I guess because of the diodes, but it's also
>got that odd dull sound found in the MS10 and 20.  So... believe it or not,
>it's a cross between an Synthi  and an MS10  VCF.  Absolutely delicious!!!

Sounds cool.  The nice thing is that you could conceivably build this thing
out of plain old op-amps and silicon diodes - no parts that you couldn't get
at your local electronics store.  

Feel free to download the schematic at http://www.seanet.com/~costello.  I
have several other circuits up, including the Minimoog ladder filter, the
EMS-like diode ladder filter, and the Moog 960 sequencer.  I will try to
post other schematics when I have the time, but I really haven't had much
time for any types of DIY stuff lately.

Also, if anyone wants to mirror these schematics on their own web pages,
feel free.  I would like to use the space for other things someday.  I will
try and scan more of my schematics, if the m-----f------ graphics program
allows me to successfully scan things in.

Sean Costello