Block Party

Call me crazy, but I always learn to use equipment faster when I have a block diagram to study. Seeing all the components, and the various ways they interconnect, does far more for me than paragraph after paragraph of text. In fact, when I’m forced to read instructions that are written in paragraph format, I find myself mentally building a set of block diagrams based on the procedures’ expected results. It’s just the way my mind works.

One of the most obvious cases where a block diagram would excel: audio mixers. They’re large, flat boxes with dozens of inputs and outputs, literally hundreds of knobs and switches, each one altering the sound in some way. Sure it can be explained with a large enough number of words, but you can only read “Aux Sends 1 and 2 are post-insert and pre-EQ, unless the Pre/Post switch is set to Post, in which case Aux Sends 1 and 2 are post-fader…” for so long before you want to gouge your eyes out. For me, I’d just like to look at a diagram and follow the line myself. It’s a much more elegant solution.

Unfortunately, not all manufacturers include such diagrams with the equipment they sell. Take, for example, the Behringer SL2442-FX PRO. Not a bad piece of hardware, really. In fact, in all the time I’ve used it, the only complaint I’ve come up with is the fact that there’s no block diagram. The instructions are quite ambiguous in a lot of areas, especially with Aux/FX routing.

I’m sure you can see where this is going…

With a 4-pack of Red Bull in one hand and a reckless disregard for common sense in the other, I started to map every dark corner of this board. I used the supplied instructions as a springboard, some other mixer block diagrams for reference, and a box full of cables to get every kind of signal into every kind of input. I tested every permutation of switches to see how the signal path changed, and some good ol’ fashioned process-of-elimination to determine in what order the audio hit each control.

I’m pretty proud of the result:

I deserve the MS Paint Medal of Freedom for this one, I think. No fancy schematic software here; just a steady mouse hand and a free weekend.

As far as I can tell, this is very close to 100% accurate. Granted, some of it may look a little ugly (especially the main EQ stage), but that’s the way the thing’s built. And as labyrinthine as this image is, the instructions were even less helpful. That’s part of the reason why I’m putting this up here. A cursory Google search indicates that there are no block diagrams for the SL2442… anywhere. I figure I can’t be the only one out there who wants a diagram for this board, so I may as well share the wealth. I’m also fairly sure that this could pass as an SL3242FX-PRO diagram, but I can’t verify that at this point.

So I beseech thee, O Glorious Interwebgod, to accept my offering. Perhaps my sacrifice will be rewarded with a well-seeded torrent or better cable modem signal levels.