[sdiy] XMOS board with Wavefront DSP (x3) and CODEC boards

[Steve Lenham]

> Noticed this on diystompboxes forum where Mark Seel has designed quite
> a powerful system targeted for guitar FX use mainly but could be used
> for some other musical purposes as well:
>
> http://www.diystompboxes.com/smfforum/index.php?topic=96073.0
>
> Reminds me of Alesis ION / Micron / Akai Miniak synths which were
> quite similar in design.

Looks like nice work by this chap, but I would warn against choosing the 
Wavefront DSPs unless you are seriously bloody-minded.

They are/were actually good parts from a hardware point of view (4 
inputs, 4 outputs, 28-bit processing, hardware log/antilog, optimised 
for audio, cheap), but if you are used to the kind of dev tools supplied 
by Microchip, etc. you will be disappointed. Wavefront's own assembler 
is basic to the point of uselessness, but the only alternative is a far 
more comprehensive but tragically unfinished tool developed by the man 
who wrote the firmware for the Ion. Enough of it works to be usable, but 
some of the features are undocumented and some of those that ARE 
documented don't work...There is also a command-line simulator written 
by some Belgian amateurs but, overall, development is not much fun 
unless you enjoy that kind of challenge.

Wavefront's support is non-existent - I'm not even sure whether the 
company still exists in a meaningful sense. They were spun out of Alesis 
during one of their regular upheavals and existed mainly to supply parts 
for the parent company. Since then, they have regularly discontinued 
parts without launching any new ones, and I see that the DSP-1K is now 
marked as "not for new designs" too.

I used them (and the matching ADCs and DACs, also discontinued) for a 
commercial project. Part way through development, Wavefront changed 
wafer fab and announced that the parts no longer worked properly with a 
+5V supply (which they were specced to do) and would only work with 
+3.3V. Guess which voltage my whole design was using...

But they were still a wasted opportunity. The Spin FV-1 is a little 
similar (maybe Spin's Keith Barr also designed the DSP-1K when at 
Alesis, but sadly he was recently, er, discontinued too) but is 
unashamedly low-end and more limited. There were hints that Spin were 
going to launch a more capable device but that seems unlikely now.

I'd love to see more small, cheap DSPs optimised for audio (i.e. direct 
interfacing to multiple converters, log/antilog, optimised instruction set).

Cheers,

Steve L.