[sdiy] Analog crossbars and backplanes

[Michael Bachman]

I use Microchip MCP42XXX 256 step digital pots for waveform mixing.
And it works great there.  Seems like it work work well in a matrix.

Mike

On Sat, Nov 9, 2013 at 11:45 AM,  <blacet at blacet.com> wrote:
> Digital pot ICs?
>
> Last time I looked, seemed to be 128 steps so not so good for frequency
> control but might make a good modulation matrix?
>
> http://www.maximintegrated.com/products/data_converters/digi-pot/
>
>> 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
>>
>>
>>
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