[sdiy] SSM chip reissue

[Michael E Caloroso]

Looking at the datasheet...  SSI2144 is an "improved" version of the
SSM2044; SMT format available, DIP is planned for future.  Works down
to +/-4v, which puts it in low voltage designs.

But... pinout is DIFFERENT.  Different enough that you DON'T want to
plug a 2144 into an existing 2044 circuit.

An SSM2040 reissue would be even better - the Rev1/2 P5s using the
SSM2040 have a very colorful resonance.  It may not have on-board VC
resonance, but the designer is free to use the feedback architecture
of their choice and it can be configured into topologies other than
lowpass.  The 2x44 includes VC resonance but the lowpass topology and
feedback architecture is fixed on the die (although it does lower
parts count).

Interesting times... we can get brand new CEM3340s and SSI2144s.

The SSM2050 VC EG was a problem IC... too much variance of transient
timing between units.  SCI had to test EVERY SSM2050 for their P5s to
get a matched set.  SSM2055 was a "replacement" that offered a pin for
trimming the transients for matching between polyphonic voices, but
CEM stole the market with their superior CEM3310.

MC

On 4/23/17, Justin Herrmann <ebn303afxcut at email.com> wrote:
> Apparently some SSM chips are going to be released, new and improved, so to
> speak:
> http://www.matrixsynth.com/2017/04/ssm-chip-production-to-return-as-ssi.html?m=1
>
> Justin
>