Pin Matrix

[Phaser Face]

Hi all,

Currently building a modular effects unit with half a dozen analogue fx and six inputs/outputs for surround sound possibilities. It would be great to be able to patch the different inputs through the effects and their various parameters. If this was done with patch chords I'm worried about the spaghetti mess. So an option is to go down the pin matrix (VCS3) route. I'm looking for help in finding more info about how these work and the advantages and drawbacks of using them.

Cheers.

[ghostarbeiter]

What's the point in modular (synth or otherwise) if there's no spaghetti?

Seriously, there's, in my view, a good reason why pin matrixes didn't catch up: you have to plan and build every connection you would possibly like, and then -in use - you decide only on whether you'd make that particular connection, or this one... While with cables you have just nodes preset (ins & outs, etc) and all the possible connections are, well - possible.

On the other hand, pin matrices could be preferred for being more, hm "localized", neater and - why not - more predetermined...

When i say didn't catch up - i mean you won't easily source a premade pin matrix of any size (correct me if i'm wrong), so you'll most probably have to go diy-route, or pay serious money.

If only premade fx's are in the play, and you don't like cables all over the place, why not get a patch bay?

[v-un-v]

What ARE you talking about?!? Everything apart from paragraph 4, I disagree with you on! Even with a common patchlead, are you not planning the way your modules are connected? The EMS synthi used a pinboard matrix, because Peter Zinovieff hated interconnection wires, ie patchcords. I believe that Zinovieff has now done away with analogue altogether and now uses computers. This is why I think, that the modern day VCS3 is a Nord Modular G2!

There's an ex-BBC VCS3 on eBay right now going for a cool £4000+ Silly money IMO. As for the patchmatrix pinboard, these are like gold dust. An Itallian firm called something like Ghillemetti make them still, but they are hideously expensive for what you get. I did once start to build a template that you could mount 2.5mm jack sockets in, designed in Solidworks, and intended to be made out of Acetal (there's a tiny company just outside Birmingham that will make simple things up in acetal for you- just give them the plans). It was one of those projects that was shelved

Phaser Face. Do I know you?!!

Tom

[drapdap]

[v-un-v]

Easy mistake to make as one part of Switzerland is Italian speaking

[ghostarbeiter]

Sorry i made the confusion, v-un-v. I was just saying that not only that pin matrix would be expensive, hard to get etc. but also that it's less flexible than simple cords.

What i am thinking is: isn't it that on a such a matrix you make an interconnection by plugging only one pin? (I haven't use one, just had a look on a big system100 here at a local radio station, that also has same pin matrix, only bigger...) If that's the case, then when you are planning a system with such a matrix, and then building it, you have to make all the connections from modules to the matrix first, so that later, in use you could make interconnections. That way, you're predetermined by the connections that are possible on the matrix.

Now, if you for example have a 20x20 matrix, then you'd want your ins from your modules wired to rows, and outs wired to columns (just to make this example clear). This -for me- serves the purpose only if 20 ins and 20 outs is all there is in your system. But what when you want to expand by adding another module? You'd have to get a bigger matrix and wire it all over, to include new module's ins and outs...

And it would especially bug me if there would be one input that couldn't be brought to the matrix from the start, because of lack of rows/columns - i'd constantly think: "if only i could plug to that input..."

For me, that's too much cons for having your spaghetti hidden... and, finally - i like the spaghetti

[Phaser Face]

Not sure if we know each other v un v. Any connection with DMU Leicester? It may be that I stick with the patchcord set up. Its easier to incorporate into the unit in some ways.

[Phaser Face]

Just wanted to check is this matrix suitable:

http://www.ghielmetti.ch/forums.html?nav=19,48,107&Category=Matrix-Boards-50VAC/6A&prod_id=56

Also still a bit confused about which of their pins will do the job. As far as I know they should be resistor pins but gheilmetti show diode pins or connector pins?

Cheers

[Electronic battle]

The link doesn't seem to work when I try it (nor does the same link in the other post where you asked if it's the right type of matrix).

The idea of the matrix is that the two axes i.e. left/right vs up/down, or if you like the x axis and the y axis, is that you have sources and destinations. You could map sources to the y axis and destinations to the y axis. Then, every point where one of the rows "hits" a column, you could put a pin into that location to route the source to the destination.

Resistor pins means that you can put a few pins on a row and send that row to several destinations, whereas a shorting poin will only allow one sopurce to go to one destination i.e. typically one pin per source (row). Diode pins are often used for sending control signals i.e. logic 1 or 0 signals in traffic light controllers etc. but from an audio and CV point of view they all have their uses in synthesiser applications.

You can use shorting pins - the ETI and Maplin synths did so - and you can use resistor pins e.g. VCS3, AK(S) and similar. A modern version is the Analogue Solutions Vostok which I think uses shorting pins.