Emu SSMs (was Re: [sdiy] A potential problem with a voice-assignable organ)

[thx1138]

On 6/6/09 1:32 PM, "Antti Huovilainen" <ajhuovil at cc.hut.fi> wrote:

> On Sat, 6 Jun 2009, thx1138 wrote:
> 
>> I also have built a DSP implementation of the SSM2044 but I never took it to
>> production. It is based upon the DSP56303 and I could easily port it over to
>> our newer devices.
> 
> Is this a full emulation that includes the non-linear effects within each
> filter stage?
> 
> Antti
> 
> "No boom today. Boom tomorrow. There's always a boom tomorrow"
>  -- Lt. Cmdr. Ivanova
Hi Antti,

Yes, I modeled this on MatLab using the DSP56300 Tool Box and Simulink.

I generated DSP code from the Older ver. 5.3 Matlab tools as this would
support the DSP56300/600 devices.

Recently I started to re-design this into SPW tools in our Audio Lab but I
had not finished it due to other work priorities.

If you want to understand the 2044, then look at the Moog filter transistor
Ladder. It was very similar, but yet a bit different in approach.

The Patents on the SSM2044 probably ran out quite a while back and it could
be nice to re-build this chip with a few improvements on Thermal stability
For tracking a CV in oscillation mode when the Q is turned up.

Still Dave Rossum did a good job on this design with Ron Dow.

Regards,

Terry