[sdiy] Substitute for pin matrixes?

[ASSI]

Hi Karl,

On Saturday 23 January 2010, karl dalen wrote:
> With the assembled brain mass here at sdiy i had hoped for a little
> bit more out of the box thinking regarding substitutes, i dont mind
> random either as long it dont end up in MT8816's! ;)

how are we supposed to do any thinking when you hog all the 
exclamation marks?

A patch matrix is nothing but a bunch of wires and some resistors 
connecting them, so if you don't mind the looks, just take a proto 
board solder down a set of IC socket strips with two thirds of the 
contacts removed (the leaf-type contacts are cheaper and work better 
for this than machined):

++o++o++o++o++o++o++o++o
+o++o++o++o++o++o++o++o+
........................
++o++o++o++o++o++o++o++o
+o++o++o++o++o++o++o++o+
........................
++o++o++o++o++o++o++o++o
+o++o++o++o++o++o++o++o+
........................

Then connect the sockets in one row horizontally, the contacts in the 
other row vertically with some wire on the back and rig some plain 
through-hole resistors with a glob of expoxy so that the wires stick 
out the same side a bit like that:

+------####----
|      ####
+-||||||###----

Build yourself a jig so that the wires are the same distance as the 
contacts in your matrix so you can just poke them into the contacts in 
lieu of matrix pins.  It's small, it's cheap, and you can have it 
working this evening.  If you don't have the epoxy it still works, 
just a bit more fiddly.  You can do more or less the same thing (but 
not looking anything like a matrix) with solderless breadboards and a 
few resistors solders to flying leads.  I've done a "memory card" on 
such a solderless breadboard for my Q+ that I've been using for years 
now.  Initially it was just meant to be a test, but it turned out to 
work so well that I couldn't be bothered to do a PCB and case.


Achim.
-- 
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk]>+

SD adaptation for Waldorf microQ V2.22R2:
http://Synth.Stromeko.net/Downloads.html#WaldorfSDada