[sdiy] Analog crossbars and backplanes

[Tom Wiltshire]

On 9 Nov 2013, at 15:15, "cheater00 ." <cheater00 at gmail.com> wrote:

> On Sat, Nov 9, 2013 at 3:50 PM, Rainer Buchty <rainer at buchty.net> wrote:
>> I think that an programmable analog crossbar is the better
>> solution in your case. Saves you all the hassles of dealing with high-speed
>> buses and you don't even need tons of ADC/DAC. Plus, scalability is rather
>> easy to achieve.
> 
> Dunno. Is it?
> 
> Let's have a 16-voice modular, with a module that has 6 connections.
> Don't you think this is a mite huge? That's 96 connections per module.
> A reasonably sized modular will have on the order of 100-200 signal
> sources and destinations. So you'd need 16 completely separate analog
> systems that can each manage 100 inputs and outputs and route between
> them. Are there any analog crossbar solutions that do anything on this
> order of magnitude?
> Then, each connection to the main hub must have additional line
> drivers, because we're talking about distances on the order of a meter
> or two.
> 
> If you find something nice, let me know, but the last time we've
> visited this topic on the list, there wasn't anything affordable or
> interesting.

Can we keep it realistic, please?

No-one has ever built a modular with a patch panel with 100 inputs and 100 outputs, let alone such a thing with 16 voices. If we're looking for solutions to such a crazy problem, it's no surprise that there aren't any answers.

But there *are* good 16x16 and 32x32 crosspoint switches out there that are easily ganged together to build larger arrays. You could easily build something that would give you more options than the largest Ghielmetti patch pin panel you've ever seen, and has memories to boot. That's not bad, even if it isn't wish-fulfillment.

T.

http://www.ghielmetti.ch
http://www.analog.com/en/switchesmultiplexers/analog-crosspoint-switches/ad8113/products/product.html