[sdiy] presets on a modular

[Richard Wentk]

At 14:22 10/11/2004 -0800, Peter Grenader wrote:
>OK, as long as we're in fantasyland here, picture this:
>
>No patch jacks, anywhere.  Instead, lit momentary buttons.  If you want to
>run an virtual patch cord from one point to the other (in this example let's
>say the saw out of a VCO into a filter input), then all's ya do is depress
>the saw out button and then immediately press the filter input button.  Once
>you do this, I see them both blinking one and off together a couple of
>times, giving you a visual indication that the connection was made.  The
>patching matrix would need to be intelligent, not allowing you to connect
>two outputs together, etc.  It would also need to be programmed so that each
>patch cord could be stepped through visually, so you could see what was
>going on in a complex patch step by step, one connection at a time.

This wouldn't be hard to do with a cheap PIC on each card. But... how big 
does the patch matrix have to be? 16 x 16 is way too low. 128 x 128 would 
be more reasonable for a useful modular, but would run out of steam on a 
big system, which might need 256 x 256 - which is 65536 switches. That 
sounds like a lot, but once you start adding up the connections on each 
module, it really isn't. And ideally you'd want each line of the matrix to 
be a summing node...

So you'd need a rather hefty analogue switching matrix board, or some kind 
of digital multiplexing system. The former is expensive and complicated, 
and the latter immediately runs into issues of bandwidth and resolution. 
especially if you're planning to send audio through it. Plus it's also 
digital. ;)

I think the interface is a side problem compared to the challenge of 
designing a patching system that can route anything to anything and works 
reliably and accurately.

We used to have an electro-mechanical telephone system in the UK called a 
Strowger exchange. If you don't mind dedicating a room to your modular, I 
expect it would do the job easily. :)

>For me, this would be the affirmation of the ultimate 21st century analog
>modular.

What? No thought control? ;)

Richard