EMS Matrix idea

[jean-charles maillet]

>Ok, here comes idea #568 to replace the expensive patchmatrix in
>a VCS-3 clone:
>
>Build a matrix from 256  *potentiometers*, and be less expensive than
>a patchmatrix or an array of 256 switches.

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wouldn't there be a potential problem with all signals being coupled
resistively, even if each is coupled through a 250k to 1Meg pot ?! ... even
if drive is low in some circuits I would suspect a very noisy system if not
by live circuits bleeding in but by ground loops throughout ... (just
thinking out loud)

... I was wondering maybe a cheaper and very easy solution (#578) is having
each VCS3 circuit on it's own card drill into a solid piece of aluminum at
one end with patch bay signals connected to screws isolated by
plastic/teflon spacer rings and with the pointy end sticking out from the
board ... I'd use alligator clips for patching ... the clips would stay on
really tight if there's enough screw sticking out ... of course there's
total absence of commercial potential here but it's the cheapest idea I've
come up with and can't see many problems except for slowness of patching
... i.e. the circuits remain electrically isolated and signals don't travel
far inside the modularizing container vessel

the other thing I was wondering about is that the 16x16 matrix must have a
certain amount of redundancy to it ... so I've been thinking alternatively
(#579) of using micro switches to patch into dedicated and undedicated
busses (i.e bus line #4 could be used to patch LFO to mudules a and b and d
and so on) ... rotary switches could be used for modules that connect to
almost anything maybe a reduction of the 16x16 subset space can be achieved
by elliminating certain types of connections (something an experienced VCS3
user would know)  based on the functionality of the modules ... general
undedicated busses could be used in addition since some modules like RM's
can accept virtually any AC signal ... the number of bus lines would be
roughly based on the number of pins in a normal EMS patch and maybe alittle
extra ... I don't know what this maximum number is for a typical VCS3
patches ...

the other solution (#580) would be to use 16 pos rotary switches on module
ins/outs throughout and having sixteen busses to all switches ... most
likely option ?! ... I might want to do the same thing with a number of
buffer circuits (Hinton) but I'm not sure yet ... these switches sell for
around 3$CDN and there'd be about 27 on a typical VCS3 design ... so
roughly $90CDN and surely lower with bulk pricing ...

... man ... Pink Floyd's DSOTM's just came on the radio and they're in the
airport running right now ...  Graham Hinton told me that the patch for
this is in the original manual; does anybody have a copy of this manual ?!

... :)~

jc


 http://www.lynx.bc.ca/~jc/    \\\\\\\\\\\\\\\\\\\\\\

     Vacuum tube modeling - Traynor amp schematics