<html><body><div style="font-size: 12pt; font-family: "times new roman", "new york", times, serif; color: rgb(0, 0, 0);"><div>How about make a short male-female adapter cable and disconnect the shell from ground</div>
<div>in the middle.</div>
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<div>I had a similar problem with some old MIDI gear, one unit did not handle the grounds correctly. It would work if it</div>
<div>was at the end of the midi chain but not otherwise. They had tied the logic ground to the case through a regulator heatsink tab</div>
<div>and the midi shell to the case. I insulated the tab and problem gone...</div>
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<div>Harry</div>
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<blockquote style="margin: 0 0 0 .8em; border-left: 1px #ccc solid; padding-left: 1em;"><hr id="MESSAGE_DATA_MARKER"><strong>From: </strong>ShedSynth <synth-diy@synth-diy.org><br><strong>To: </strong>synth-diy <synth-diy@synth-diy.org><br><strong>Date: </strong>Wednesday, 18 January 2023 12:32 PM EST<br><strong>Subject: </strong>Re: [sdiy] M-Audio Midisport Uno Wire to pin ?<br><br>
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<p class="MsoNormal">An update: I have just bought a <span lang="EN-US">M-Audio Midisport UNO.</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">And I’ve got myself a hum-loop:</span></p>
<p class="MsoNormal"><span lang="EN-US">The shell of the UNO’s USB-A plug has a connection to the shell of the MIDI OUT plug (but not to the shell of the MIDI IN plug).</span></p>
<p class="MsoNormal"><span lang="EN-US">And my home-built MIDI module (<a href="https://shedsynth.wordpress.com/midi/" target="_blank" rel="noopener noreferrer">https://shedsynth.wordpress.com/midi/</a>) has a metal DIN socket on the front panel which is grounded through the rack.</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">And it doesn’t seem to work with my MIDI module:</span></p>
<p class="MsoNormal"><span lang="EN-US">I measure the UNO’s MIDI OUT signal level at 3.3V, which doesn’t seem enough to light up my 6N138 with recommended 220R series resistor.</span></p>
<p class="MsoNormal"><span lang="EN-US">The UNO variously does or doesn’t play through my other MIDI devices.</span></p>
<p class="MsoNormal"><span lang="EN-US"> </span></p>
<p class="MsoNormal"><span lang="EN-US">I wasn’t expecting to ask for help, just thought I’d follow up on this thread when it arrived.</span></p>
<p class="MsoNormal"><span lang="EN-US">But now I’d appreciate any guidance.</span></p>
<p class="MsoNormal"><span lang="EN-US">Thanks,</span></p>
<p class="MsoNormal"><span lang="EN-US">Al</span></p>
<p class="MsoNormal"> </p>
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<p class="MsoNormal"><strong><span lang="EN-US">From:</span></strong><span lang="EN-US"> ShedSynth <shedsynth@gmail.com> <br><strong>Sent:</strong> 14 January 2023 09:52<br><strong>To:</strong> synth-diy@synth-diy.org<br><strong>Subject:</strong> RE: [sdiy] M-Audio Midisport Uno Wire to pin ?</span></p>
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<p class="MsoNormal">Re the video’s complaint that only MIDI IN is opto-isolated: I think I’m right that this is correct implementation (please contradict if not).</p>
<p class="MsoNormal">The MIDI OUT on any device is actively driven from the device’s own power, and whatever MIDI IN you plug that into will/should be opto-isolated so no ground loop or smoke.</p>
<p class="MsoNormal"> </p>
<p class="MsoNormal">But the video is probably right about the £5 USB/MIDI interfaces not isolating MIDI IN.</p>
<p class="MsoNormal">Does anybody know any cheap USB/MIDI cables which do isolate?</p>
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<p class="MsoNormal"><strong><span lang="EN-US">From:</span></strong><span lang="EN-US"> Synth-diy <<a href="mailto:synth-diy-bounces@synth-diy.org" target="_blank" rel="noopener noreferrer">synth-diy-bounces@synth-diy.org</a>> <strong>On Behalf Of </strong>Nathan Trites<br><strong>Sent:</strong> 13 January 2023 16:26<br><strong>To:</strong> David Messenger <<a href="mailto:mssngr1@pacifier.com" target="_blank" rel="noopener noreferrer">mssngr1@pacifier.com</a>><br><strong>Cc:</strong> <a href="mailto:synth-diy@synth-diy.org" target="_blank" rel="noopener noreferrer">synth-diy@synth-diy.org</a><br><strong>Subject:</strong> Re: [sdiy] M-Audio Midisport Uno Wire to pin ?</span></p>
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<p class="MsoNormal">If you havent sorted this out yet - here is a youtube video where you can see how it's wired: <a href="https://youtu.be/Xv5-5CUNFvI?t=75" target="_blank" rel="noopener noreferrer">https://youtu.be/Xv5-5CUNFvI?t=75</a></p>
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<p class="MsoNormal">Nathan</p>
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<p class="MsoNormal">On Sat, Jan 7, 2023 at 5:14 PM David Messenger <<a href="mailto:mssngr1@pacifier.com" target="_blank" rel="noopener noreferrer">mssngr1@pacifier.com</a>> wrote:</p>
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<p class="MsoNormal">I have to rewire the in/out DINs on a Midisport Uno that lost it's midi <br>plugs. There is one wire that has red-black-yellow and a bare ground, <br>and then the other cable has just red and white. Anyone know which pins <br>each of these wires should be reattached to? TY D.<br><br><br>-- <br>This email has been checked for viruses by AVG antivirus software.<br><a href="http://www.avg.com" target="_blank" rel="noopener noreferrer">www.avg.com</a><br>_______________________________________________<br>Synth-diy mailing list<br><a href="mailto:Synth-diy@synth-diy.org" target="_blank" rel="noopener noreferrer">Synth-diy@synth-diy.org</a><br><a href="http://synth-diy.org/mailman/listinfo/synth-diy" target="_blank" rel="noopener noreferrer">http://synth-diy.org/mailman/listinfo/synth-diy</a><br>Selling or trading? Use <a href="mailto:marketplace@synth-diy.org" target="_blank" rel="noopener noreferrer">marketplace@synth-diy.org</a></p>
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