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

[Tom Wiltshire]

On 6 Jun 2009, at 16:10, thx1138 wrote:

> Any idea where I can find SSM devices such as ssm2020, 2010, 2030,  
> 2040,
> etc. ?

You'll be extremely lucky to find any of the chips listed. Which is  
not to say it's impossible, but expect to pay for them. Some SSMs are  
still available, for instance there still seem to be reasonable  
numbers of SSM2044s around, but even these won't last for ever, and  
they're not getting any cheaper.

The VCAs you will find modern equivalents for. THAT Corp and Analog  
Devices both still make VCAs, and the venerable LM13700 is still  
around in one form or another.

The SSM2040 has been cloned using discrete components by JH on this  
list, and George Hearn has produced a DIP-format SMD module of this  
chip.

The SSM2030 oscillator is completely gone though. I have no idea what  
IC audio oscillators there are out there.

Unfortunately, the heavy use of the SSM chips means that a lot of the  
Emu designs are not really a realistic prospect for modern synth  
builders. Which is one reason people keep going back to earlier stuff  
which was mostly discrete - after all, you can still get transistors!  
On top of that, the matching between units and quality has improved  
enough that some of the disadvantages of this approach originally are  
now no longer such big issues as they were.

Regards,
Tom