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Easier Measurement Makes a Happy Modular

Nov 12, 2010 Gear
Posted by irfon

If you own a modular analog system or even just a synthesizer or sequencer that communicates using control voltage, at some point you’ll resort to measurement, and once you’ve begun on that road there’s no turning back.  Many modular owners have a great deal of fancy test equipment, but the basic starting point is a good digital volt meter (or multimeter).

However, if you’re like me, you’re fairly new to all of this and you don’t have a collection of different probes with various connections, etc.  You may (again, like me) have just picked up your first nice meter and you just have the probes that came with it — the ones that look like you could stab someone with them.  If, again, you’re like me, you’ve tried to live with them by alligator clipping leads between cables and probes, weighing probes against plugs, coming up with all many of rigged solutions.  Well, there’s an easy solution.  I imagine most people have something that covers this, but it only occurred to me today, and I was able to whip up this quick fix for just a few bucks (bearing in mind that I already had most of the tools) and maybe an hour or less of work.  I think it’ll have saved me at least that much effort by the end of the week.

I feel like I’m making a bigger deal with this leadup than it deserves and I felt pretty silly posting super detailed instructions, so instead I’ll just show you the mod:

As you can see, it was simply a matter of cutting the probe leads in half and connecting the end closer to the meter to a 1/4″ female monophonic unbalanced (2-connector) jack, and the end closer to the probes to a 1/4″ male monophonic unbalanced (2-connector) plug.

This way, when I’m measuring the modular, I can plug patch cords directly into the multimeter, which is hugely easier than what I was doing before.  (Let’s not even go there.)  However, if I want to use the meter with the probes as originally designed, I can just jack them back in and away I go.

My test measurements before and after check out, and it seems to work great.  THis is going to be a huge time and headache saver for me.  All I had to buy (other than the various tools and such, which fortunately I already had) was the jack, the plug, and a few inches of heat-shrink tubing.  I made about a billion mistakes, because I’m clutzy, but maybe an hour of total time and only two of my fingertips burned later, my dreams had come true.  :)

The biggest lessons learned in this project:

• Measure reference voltages before beginning that you can use to accurately verify that it all works after.  It’s a lot harder to obtain this data after you’ve sliced your probe leads in half.
• Make sure to slide all the tubing and barrels and anything the cables have to go through into place before you start connecting and soldering.  (I forgot this one maybe six thousand times.)
• Metal components that have been recently soldered tend to be very, very hot.  (Ow!)

(Note: If you’re very new to soldering and need detailed instructions, please contact me!  Seriously, I don’t mind writing them out for you.)