02 December 2009

VU Meter (Part 1)

Last week I visited my local electronics shop again to pick up some parts and found out that they also sell a lot of nice electronics DIY kits from Velleman. I never though much of those, but when I browsed through them recently I did find some interesting stuff. To start with I found a stereo 15 led VU meter kit. I though what would be neat to integrate into a mixer module I'm building, so I decided to check it out. As you can see it comes in a neat box so it looks promising. So time to unpack.

And here is the content of the package. It is all very well documented and even suited for beginners I think. What is especially neat is that all the PCB components are on a roll strapped together in the right building order. So you can't even go wrong picking a wrong component value as long as you stick to the documentation. It also came with a plastic kind of front panel that I didn't think was very suitable to fit my modular. But more about that later on.

And construction was very easy, but then I hooked it up to my electronic snare drum project and saw that only the left side was working. After close inspection I found that while bending one of the Elcos I damaged a PCB trace. So I repaired that with some wires on the bottom of the PCB. And then it worked like a charm. It is nice to have some kind of level indication in a modular setup I think. The only problem with this kit is that there are two potmeters on the PCB to calibrate it and they are 1 turn. So it is very touchy. I think 25 turn would have been better there.

I was thinking about integrating this VU meter into a mixer that I'm building, but I found out quickly that 15 leds in a led holder takes more space than I thought. So I decided to design a separate front panel for it. You can see that in the picture on the right. I just hope I left enough room between the led holders. Well we'll see :) I gave it also outputs so that I can easily chain it somewhere in between an audio signal path. I'll let you know how it turns out eventually. If you are interested in any of the front panel designs I'm doing by the way just let me know and I'll send you the FPD files. This was a nice in between project while I'm still waiting for parts to arrive to finish up some other projects. I already picked up another Velleman kit as well that I will tell you about very soon. If you are interested in them just look at http://www.velleman.eu

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