[sdiy] Prophet VS a phase accumulator design

[karl dalen]

Speaking of reverbs, could be an interesting topic, i have an old ART verb
with two Z80 seemingly running in parallel, on takes top byte other low byte and a discreete logic wich these two runs into wheter the logic
does the actuall computation, i guess it do, some kind of spedy MAC
and Dram but unsure its a 16 bit stereo device, multiplexed PCM54.

I will have a look into some of the Dittmar patents anyway.
Looking forward to the write up i your going to publish it.

KD

--- Den lör 2011-02-05 skrev Scott Nordlund <gsn10 at hotmail.com>:

> Från: Scott Nordlund <gsn10 at hotmail.com>
> Ämne: Re: [sdiy] Prophet VS a phase accumulator design
> Till: 
> Kopia: synth-diy at dropmix.xs4all.nl
> Datum: lördag 5 februari 2011 18:39
> 
> > > (I believe the designer's name is Wilfried
> Dittmar, maybe I
> > > should try to bug him about it).
> >
> > Which of his patents are wort studying/of importance?
> > http://www.google.com.tw/patents?tbm=bks&tbo=1&q=Wilfried+Dittmar&btnG=Search+Patents
> 
> I think Dittmar was the main designer at Wersi. Of the
> patents that I've seen, 4572048 and 4644840 cover the DMS
> digital synthesis engine (it's not much of a revelation).
> 4096778 covers the Wersivoice chorus circuit, but this is
> just a standard 3 BBD string chorus with optional
> feedback/feedforward paths and speed control. There are
> technical manuals that better describe the same material,
> but I wouldn't call it a thrilling read in any case. The MK1
> and EX20 do some very interesting things (crude formant
> synthesis and the strangest envelope generators ever
> conceived), but this is all done in software. The hardware
> designs are curious but probably not worth studying on their
> own. Some organs used up to 25 or so microprocessors in a
> card cage, including an extremely crude MC6809-based
> "reverb", and the analog Wersimatic CX1 had some pretty odd
> analog drum sounds (I need to find one of those!). But I
> don't think most of it is very helpful or informative in
> 2011.
> 
> Well, I'm working on a big writeup with lots of technical
> info and sound demos and stuff.
>     
>         
>           
>   
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