Some changes to schematics (original "I screwed up")

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Re: Some changes to schematics (original "I screwed up")

Postby dmitri » Sat Dec 08, 2007 12:10 am

TriggerThis wrote:I think I may have found a little problem with the MIDI IN connection in the schematics.

Pin 2 of the MIDI IN jack should not be connected to ground according to numerous MIDI documents I have. Also, when I look at the schematics of all the MIDI equipement I have here, including Roland's Octapad II schematics, none of them have PIN 2 of the MIDI IN connected to ground.

Seems it has to be done like that in order to prevent ground loops ... thats also why there is an opto-isolator at the MIDI input.


Well, if any other MIDI equipment doesn't have this pin connected than it won't matter if MegaDrum has it connected or not, will it?
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Re: Some changes to schematics (original "I screwed up")

Postby TriggerThis » Sat Dec 08, 2007 12:25 am

I think it will, because all other MIDI equipment MIDI OUT has PIN 2 connected to ground.

But it wont if you dont use MIDI in :roll: ... but its not a big deal, its easy to fix, just cut one wire, or 2 if you also connected the ring of the jack to ground.

The MIDI IN ring should also not be connected to ground.
Last edited by TriggerThis on Sat Dec 08, 2007 12:36 am, edited 1 time in total.
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Re: Some changes to schematics (original "I screwed up")

Postby dmitri » Sat Dec 08, 2007 12:31 am

I see. I'll make the change in the schematic.
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Re: Some changes to schematics (original "I screwed up")

Postby Synthex » Sat Dec 08, 2007 1:58 am

In MIDI specification, IN MIDI ring and pin 2 must not be connected to ground.
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