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LSDJ-MC2 Revisited: 5 common mistakes, Plus one moreGreetings! It’s been about three years since the last installment, and I thought it was about time to give the topic a little more attention. There are still many of you who are looking to build a LSDJ-MC2 and either lack the skill or otherwise too busy to complete the task, and I have to say this is still an average skill job, not really that complicated. With simple soldering skills, the right parts, and a little determination a LSDJ-MC2 can be yours. Background to the project: Let me explain the main reason I'm writing this article... About 3 months ago Tony Miller Aka Robotcheese e-mailed the LSDJ-MC2 list on yahoo asking for someone to put a LSDJ-MC2 together for him, he was willing to pay and ship the parts to the willing party - he even offered to pay for the work. I took on the job, because I needed a good summer project and I told him I'd do it for free so I'd be sure to get the job :) I went to work busting out a breadboard and slapping pieces on. But I noticed some of the parts were wrong.. And along the way I found even more road blocks! So the main reason I'm writing this article is to clear up some common mistakes, I myself made the first and second time I put one of these together. Common Mistakes, if you power it all up and nothing happens: 1) Take a look at Firestarter's parts list The 22pF capacitors (C3, and C4) MUST be ceramic! And they absolutely must be ceramic! No really, they have to be. The reason is that the 20mhz crystal that they sit so snugly up against admits RF interference and other types of capacitors will not work because of this - only ceramic work in this situation, trust me. For good measure its also good to get a 100nF ceramic capacitor for C1, but it shouldn't matter as much, though that's what I've always used and it works great. So might as well. 2) While still looking at the parts list and still on the topic of capacitors make sure you get 10uF (C2, and C7) electrolytic that are polarized. Because if you don't - it won't work. And make sure they are pointing the right way. The side with the "----" things go towards ground. 3) D1 the 1N4148 diode must be a switching diode. 4) In the Schematics it says that the Midi out is female - it's actually male. Meaning if you have a male midi cable coming out of your MC2 then it's correct, if your going to have a female plug on the back of your MC2 so you can plug a male into it, then it's incorrect (just swap the wires). 5) After you set everything up and when you turn it on you get the neat little display of lights that looks like this: Reply |