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Subject: Re: arp matrix switches

From: Mark Pulver <mpulver@...
Date: 1999-07-09

mark scetta (10:48 AM 07/09/1999) wrote:

>i saw an old arp modular at someone's house recently that, instead of jacks,
>it had dozens of tiny sliding switches that formed a huge matrix grid. each
>position made a connection when the slider was moved into one of its 10 or
>so locations.

This is the ARP 2500.

Many pics are here, including a list of most of the modules:

The normal "bitch" about the 2500 and the matrix is crosstalk between the
columns. This is usually more overblown that it real should be.

There ∗is∗ crosstalk between the columns, but this is actually part of the
character of the machine. It really isn't ∗that∗ bad, and most of it isn't
because of the matrix anyway... The power supply in the machine is often
the culprit of most of it.

Past that.. The matrix tends to take up a LOT of space. The pictures above
show that pretty well.

And past that... It _is_ cool. :)

>this is supercool BECAUSE instead of plugging in patchcords for desired
>routings, one could flip a bunch of switches, and in the process, flip some
>switches accidentally and stumble upon lots of new unintended sounds! very
>cool. is there an interface like this that i could DIY for the MOTM?

The problem with the matrix switches is that they are VERY expensive.
DigiKey and other folks still sell them (they're made by EDAC now) but even
a small matrix will run $300 or more.

The latest DigiKey catalog has them (Catalog 0993 pg439).

Part# Size∗ Cost each
151-1054-nd 20x40 341.46
151-1055-nd 10x20 215.14
151-1056-nd 10x50 341.46
151-1057-nd 48x58 763.51

∗rows x colums

DigiKey online is here:

The specific catalog page is here as a PDF file (lower right corner):

When I first got into synths (1975ish) I was building PAiA gear. At one
time, I rigged an external box with a 10 x 20 matrix switch that I had
found surplus at a hamfest. I ran a cable from the back of the box to the
PAiA cabinets and had a field day with the matrix.

Very cool...

btw... Interesting friends you got. :)


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