[sdiy] Polyevolver internals

[Tom Wiltshire]

On 29 Dec 2009, at 22:11, Eric Brombaugh wrote:

> On 12/29/2009 02:14 PM, Tom Wiltshire wrote:
>> Hi All,
>>
>> Does anyone happen to know what voice processors are inside the DSI
>> Polyevolver/Evolver? Alternatively, are there any good internal  
>> photos
>> of one of these opened up?
>>
>> I've had a hunt about, but I didn't find anything.
>>
>> Background: After the recent discussion about the Prophet 08 DCO  
>> glitch,
>> I'm spending my Christmas holidays messing around with DCO designs  
>> based on
>> dsPICs, just like Dave Smith did. What's intriguing me is what he  
>> used
>> for the *digital* oscillators in the Polyevolver - are they  
>> generated by
>> the same uP? How many uPs per voice? Or put another way, how much did
>> DSI manage to squeeze out of these chips, and can I hope to do  
>> better?
>>
>> Thanks for any pointers,
>
> I found this site:
>
> http://www.hispasonic.com/comunidad/evolver-inside-t243152.html
>
> You can see that he's using the PA397 for the DCO there too.
>
> Stephan Tippler's site indicates that the Evolver's digital  
> oscillators are generated in the DSP, which appears to be an Analog  
> Device ADSP-2191. A lot more going on in that part than in a dsPIC.
>
> Eric

Thanks Eric. That pretty much clears that up. I guess Karl is right  
about the long delay lines needing more than a dsPIC, and a ADSP2191  
would give you a lot more scope.

<returns to bench>
That lets me off trying to squeeze digital oscillators into this chip  
too, then! Phew!

T.