Rakesh Anderson Posted August 7, 2012 Report Share Posted August 7, 2012 I have a couple of questions about direct output mods for a mixer I have. I hope someone can give me a little more insight. The mixer is a JVC mi2000u. I've contacted JVC and they no longer provide support for this old beast. My plan was to tap the hot signals from the PFL switch, and was told by a former teacher and electronics guru to ground as close to or on the power supply, and I could even ground to the main output if need be. I was going to use a 9 pin d-sub with a breakout on the other side, as I've seen others here use. The advice I got was to use a heavier gauge wire from the ground of the power supply to the dsub on the back panel because: "Any crosstalk you might get will probably be from the different channel currents adding up and flowing on the same ground wire, so if you keep that wire large, and do the breakout close to your d-sub to minimize the shared impedance, that should be helpful." This makes sense to me, but I wanted to see what others think of this approach, because I've also heard to avoid grounding to the power supply. Thanks RAkesh Quote Link to comment Share on other sites More sharing options...
studiomprd Posted August 7, 2012 Report Share Posted August 7, 2012 ehh... how much electronics experience do you have ?? (OK, I'm guessing not enough) there are a number of factors to consider, cross-talk, is only one --ground loops, another! that said, solid ground connections are always a good practice. Quote Link to comment Share on other sites More sharing options...
RandyHall Posted August 7, 2012 Report Share Posted August 7, 2012 solid ground connections are always a good practice. Impedance matching is another, when appropriate. Quote Link to comment Share on other sites More sharing options...
Rakesh Anderson Posted August 7, 2012 Author Report Share Posted August 7, 2012 You're right Senator, not much (Although I did take extensive courses in college, and have since forgotten most of it). But this is purely for the experience. I can always undo what I do if it's bad, and it really isn't that complicated of a mod. Thanks for the input. Quote Link to comment Share on other sites More sharing options...
Tom Visser Posted August 8, 2012 Report Share Posted August 8, 2012 make sure that whatever point you tap the D.O. from has sufficient isolation from the surrounding circuit, so that activating the PFL, for example, wouldn't introduce a click or pop into the D.O. signal, compromising its functionality. A resistive network, also for proper impedance matching, or an active buffer circuit can be used to provide the necessary isolation required. Quote Link to comment Share on other sites More sharing options...
Rakesh Anderson Posted August 8, 2012 Author Report Share Posted August 8, 2012 make sure that whatever point you tap the D.O. from has sufficient isolation from the surrounding circuit, so that activating the PFL, for example, wouldn't introduce a click or pop into the D.O. signal, compromising its functionality. A resistive network, also for proper impedance matching, or an active buffer circuit can be used to provide the necessary isolation required. Thanks Tom. Quote Link to comment Share on other sites More sharing options...
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