C
Charmed Snark
- Jan 1, 1970
- 0
I'm trying to come up with a microprocessor solution to
replace the traditional analog synth patch cords, using an
analog crosspoint switch.
The idea is to replicate the mechanical matrix used in this
synth, but under microprocessor control:
http://www.vintagesynth.com/misc/vcs3.php
Google yielded some crosspoint video (analog) switch chips
with memory (latching). I came across some chips like the old
74HC22106 and the newer ADG2188 etc.
These almost solve the issue except that there is no 10k
isolation resistor (say) at the crosspoints. You could add 10k
resistors to the inputs (say columns) but if one input was
patched to more than one output line, then those two outputs
would be only isolated by about 50 ohms. So cross talk would
be a problem.
So my question is this- are there any crosspoint switch
solutions that include an isolation resistor at each
crosspoint?
The isolation resistor at each crosspoint allows each patch to
automatically be summed (mixed) like the typical summing opamp
circuit. It will also provide some level of isolation between
each line.
Warren
replace the traditional analog synth patch cords, using an
analog crosspoint switch.
The idea is to replicate the mechanical matrix used in this
synth, but under microprocessor control:
http://www.vintagesynth.com/misc/vcs3.php
Google yielded some crosspoint video (analog) switch chips
with memory (latching). I came across some chips like the old
74HC22106 and the newer ADG2188 etc.
These almost solve the issue except that there is no 10k
isolation resistor (say) at the crosspoints. You could add 10k
resistors to the inputs (say columns) but if one input was
patched to more than one output line, then those two outputs
would be only isolated by about 50 ohms. So cross talk would
be a problem.
So my question is this- are there any crosspoint switch
solutions that include an isolation resistor at each
crosspoint?
The isolation resistor at each crosspoint allows each patch to
automatically be summed (mixed) like the typical summing opamp
circuit. It will also provide some level of isolation between
each line.
Warren