[sdiy] Digital modular backplane - update

[john slee]

On 17 March 2014 22:24, cheater00 . <cheater00 at gmail.com> wrote:
> This has to take into account the
> situation that an ADC or DAC will operate at low clock speeds, while
> the backplane would operate at very high clock rates, in order to
> accomodate many ADC-DAC links in the switched, TDM fabric.

This is the part that bothers me the most, even more than the control
surface aspect. I don't want to get into digital vs. analog flamewars. I'm
sure we're all sick of those.

But it seems that this backplane design would introduce a whole bunch
more A=>D=>A=>D=>A... conversions than strictly necessary. I suspect
that you'd be better served in building custom MIDI control surfaces for
something like Creamware/SonicCore's SHARC DSP-based modular,
where all the signal paths are (IIRC) 24bit/96kHz internally, with A<=>D
only at the very edges, and only once (if at all; could use ADAT instead)

On a related note - and following on from Gordon's post of Olivier's
"breadboard friend" PCB designs a while back - I've designed a MIDI
in+out breadboard friend. Going to give it a final check over this
weekend and send the Gerbers off to Seeed. If it works I'll have a
few spare PCBs to share with SDIY folks.

John