[sdiy] New long term project

[Greg James]

David,

Nyle is still around. You might want to try contacting him. Matt Traum,
matt at patchmanmusic.com, is probably your best shot at getting through to
him. IMO Matt is the leading expert on EWIs/EVI's and still does work with
Nyle from time to time. I've tried contacting Nyle myself and have never
gotten a response. But I've not tried specifically through Matt. Given your
personal history with Nyle, I think you might have better luck.

A wonderful dream: Nyle jumps on the bandwagon and re-issues a modern
Synthacon...

-Greg

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of David Ingebretsen
Sent: Monday, August 10, 2009 9:53 PM
To: 'synth-DIY'
Subject: [sdiy] New long term project

For purely nostalgic reasons (short history below if you are interested) I
want to build a Steiner-Parker Synthasystem/Synthacon clone. Nyle gave me
schematics to his modules in 74, but (long story) they are gone. I found
some Synthacon schematics which nearly fit the bill but I have some
questions.

While I can read a schematic, and I took upper level EE classes as an
undergrad and some more in grad school, I am -not- pretending to be an
analog guru.

In the schematics, the matched NPN pair (2N5172, I still have a boatload of
them and the PNP's Nyle used from when I was building an SP in 74, but alas,
no FET's) is a pair of discreet transistors which were bent over and a
thermistor stretched across the both of them. 

	1a.	Can this pair be replaced by an SSM chip? What
characteristics would be important when trying to see if I can substitute
the SSM chip? 

	1b.	Is it your experience that making this substitution will
somehow change the character of the oscillation? I hated matching transistor
pairs back then, and don't think I'll like it any better now but will do it
if it will preserve some audio quality.

	2.	Next, as I lamented, I don't have the old 2N5163 FET. I have
found some cross references, but am unsure again which parameters I need to
compare to match them. Can I just trust the cross reference charts and
blindly substitute the one recommended?

For what it's worth, this is not for profit, or sale. I just want to say I
finished what I started as a 17 year old so many years ago.

Thanks
David


***********************************
Historical note:
Nyle was my neighbor and I don't know how, but I got his name as I was
becoming interested in synthesizers. I called him and he invited me over. I
left with a fistful of schematics and was totally inspired. Over the course
of the next 9 months or so, he gave me more help, demonstrations, and even a
summer job soldering PCB's in his shop. I only ever got a VCO and keyboard
working. Life happened, I was gone for a couple of years and my brother
threw it all out, schematics and all. All I have left are a handful of pots,
and some transistors.

So, with my mid-life crisis in full gear, I am now at a point where I want
to finish the thing that really got me started. I want to build a true
Steiner-Parker synthesizer voice. VCO, VCA, VCF, EG at the least.

I don't know what I'll do with it other than look at it and feel happy :)

************************************

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy