SSM2038 Schems?

[Scott Bernardi]

The Synthesis Technology sight has the SSM2013 (VCA), SSM2014 (VC Element),
SSM2015 (mic preamp), SSM2120/22 (dual VCA), SSM2044 (4 pole VCF), and
SSM2045/2047 Voice (Filter + VCA) datasheets. No SSM2038. They also do not
have any of the SSM chips on their pricelist.

There seems to be a real dearth of VCO chips of any type. The only place
I've seen advertise availability of ANY kind of VCO chips is the CEM3374
dual VCO on Synthesis Technology's page ($15). A dual VCO sounds great, but
to temperature compensation is not complete on the chip. It provides a
reference voltage that you have to multiply the control voltage by (which
is what we do with a tempco resistor). You can do this under digital
control with a multiplying DAC, or using analog multipliers (one for each
VCO).

I sent an email last week to DB Musical electronics, which advertises that
they carry SSM and CEM chips, asking about what they actually have in
stock, so I could share it with synth-diy. Haven't gotten a reply yet.
(They did quote me $30 for a CEM3340 VCO a couple of weeks ago. Pretty
steep, but I guess that's supply and demand).

And speaking of sources, where do you guys get things? For example, I've
seen Farnell mentioned as a source of the Q81 resistor on more than one
message, yet I sure can't find it when I search on their web site.
What about matched pnp's - AD821, MAT-03, etc? Has anybody looked at the
MPQ2907 (quad 2N2907 pnp's)? They're probably not monolithic, but are they
matched enough to make a decent current mirror (to mirror a matched npn
exponential current sink into sources for OTA's). 

Full of questions. Seems to be the biggest hurdle to someone doing a DIY
synth these days is getting the necessary parts (I built one in the early
80's, and stuff was plentiful back then. I'm coming back after a 16 year
absence).

At 07:31 PM 5/7/98 +0200, you wrote:
>
>-----Original Message-----
>From: Yoshiki Ohmura (Yoshi) <yoh212 at lulu.acns.nwu.edu>
>To: synth-diy at mailhost.bpa.nl <synth-diy at mailhost.bpa.nl>
>Date: Thursday, May 07, 1998 7:45 AM
>Subject: SSM2038 Schems?
>
>
>try this: http://www.synthtech.com/cem/cemdata.html
>
>>I just got a few of the SSM2038 VCO's with an order of chips, and I was
>>wondering if anybody had some schematics for these chips.  I really don't
>>know anything abou them, there seems to be no lit. on those chips.
>>
>>Thanks
>>
>>Yoshi
>>
>>
>
>
>
--------------------------------------
Scott Bernardi
voice: 415-538-0439 (note new number)
fax:   415-904-8375
scott.bernardi at fritz.com