Looking For Filters

[media at mail1.nai.net]

Thanx for all of the filter building advice so far.  May anyone suggest a
source for filter schematics??

At 9:23 AM +0000 11/14/97, John E Blacet wrote:
>Paia has basic kits for Craig Anderton's Electronic Projects for
>Musicians. There are 27 projects and three filters. A very good place to
>start!

I built a Paia Theremax a while back and I wasn't crazy about its
performance.  The output was very noisy and the CV outputs were very
anemnic (0-1.5 V).  I cleaned up the sound a bit which included replacing
the output amp that came with the kit (would you believe a 748 ?).  I
still have to build voltage buffers for the CV.

Perhaps I should just get the Craig Anderton book first.  I am thinking of
using a Paia Frac Rac to house my modules.   I think Paia is a good
company, but I wonder if any of these filter kits would suit my
applications.

At 1:51 PM +0100 11/14/97, Matthew S. Padden wrote:
>Well, I found myself in precisely this situation last year. I decided to
>build a small set of Digisound modules, which would give me the same
>functionality as a Mutator, but also be capable of many other things. Price
>wise (over time) the difference may not be that great, but you find
>yourself with a lot more features and a great deal more flexibility.

Great :)  How do I get in touch with Digisound??

>Having found a nice 6U Eurocard rack frame, I decided on the following
>module complement (the model numbers may be wrong):
>
>2x DG80-7 state variable 12/24dB VCF, using SSM2040 ICs
>2x DG80-4 24dB VCF, using CEM3320 ICs
>2x DG80-10 VC Envelope Shaper, using CEM3310 ICs
>1x DG80-9 Dual VCA, using CEM3330 IC
>2x DG80-?? Envelope follower
>2x DG80-2 VCO, using CEM3340 ICs
>1x DG80-?? waveform multiplier OR ring modulator

That sounds like a very nice rack :)   How did you get a hold of all those
Curtis chips??  Haven't they been out of production for years??  Does
Digisound have their own private stash that they take from when you buy the
kit??

>So far the DG80-7 VCFs are finished and sound superb. The DVCA and VCES
>modules are almost complete (money is tight! :) ). There is also space in
>the rack for the Digisound +/-15V PSU built round the 723 regulator.

I am also thinking of building a +/-15V power supply.  I figure it is the
best general choice for a wide number of op-amp circuits.

PEACE OUT :)
MARK

---
"It's like, when a band has a name like 7 Year Bitch,
 it's like, they don't have to be very good."
                                  -- Butt-Head