5-pin MIDI cable bi-directional if all pins wired

bwanagary

bwanagary

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I found this post on the forum from the Fractal Administrator in 2009. I thought that it might be helpful to someone so I'm reposting here.

MIDI is a current loop and requires two wires for the data, hence data+ and data-. Pin 2 should be grounded only on the sending end, i.e. the controller. Pins 1 & 3 are typically no connect but the Axe-Fx uses them to send MIDI data for bidirectional communications with the MFC-101. Pins 6 & 7 are connected to the phantom power jack on the back of the unit.
 
Maybe you can help me with a problem, I updated to Quantum ver1.0 using a 7pin midi,and power adaptor. Then I updated the MFC101 to 3.08. A week later I purchased the MFC101 editor. I was get ready to made the 7pin midi/adaptor connection,and i didn't get a connection. The mfc101 wouldn't light up at all.
 
Hi Waltdude. It isn't really an editor problem but let me see if I can help. First things first; You'll need to make sure that the 7-pin cable is truly a 7-pin cable and that it doesn't just have 7 pins the Din plugs. You can do that with a tester of any kind. Assuming that there are indeed 7 conductors in the cable, the next thing to know is that Axe-Fx will not actually power the MFC-101 over a MIDI cable. You'll need to connect the MFC-101 wall-wart into the back of the Axe-Fx - there's a place to plug that in. The Axe-Fx simply routes that power input to the MIDI cable. I'm guessing that's the most likely cause.
Did you connect the MFC-101 power supply to the back of your Axe-Fx?
-G
 
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Hi bwanagary; Thanks for the reply, and yes it worked before. I tested the wall-wart, and It has 12volts output at the connection. I moved it to another extention cord on my desk, and still can't get a connection response at the MFC101. Now I am considering picking up a 5 pin midi and trying that connection, I am a stickler for things that don't work, and want to know why. Sorry for the long read. I'm at work, and will be home at 3pm. I will make all connections once again and see if it wasn't something wierd.
 
The correct power supply for the MFC-101 is 9v AC, 1000mA. 12V might even be enough to damage it.
 
Thanks for the reply again bwanagary ; It is the Fractal power supply.If you have a multimeter, I'm wondering what yours reads.I am getting 12.9vac output. Now that in turn may not be a problem, the amount of amperage is what's important. It does power up when I plug it directly into the MFC101.
 
Ah, if it does power up when directly plugged into the MFC-101 but not through the Axe-Fx I'd have to suspect the MIDI cable quality and length. Maybe voltage/amperage drop due to inadequate conductors in the cable. Still, the MFC-101 consumes less than 10 watts so I'd be surprised. I measured my own Fractal-supplied transformer and it read 11vac consistently. Its probably something to do with the design and I need to measure it under load. I'd suggest trying a different MIDI cable and use the multimeter to ensure that pins 1 and 7 go through from end-to-end unperturbed. Maybe measure the voltage at the MFC-101 end of the MIDI cable to make sure. Beyond that you'll probably need to open a ticket with Fractal support and get someone more knowledgable with all the components.
 
Sorry, but what does this bi-directionality mean in practice? Does it mean I shouldn't reconnect the cable when sending dumps to and from the MFC?
 
But for this to work, don't jacks on devices also need to be bi-directional?

Let me dumb it down a bit. If I connect MFC's MIDI Out with AFX's MIDI In with such a cable, I can upload a dump file. If I want to transfer it back to the MFC, do I need to plug it to different jacks? I don't think it worked for me.
 
That's the intent. I don't know of other devices that can do that. The Axe-Fx and the MFC-101 have their MIDI connections specially wired to be bi-directional. Both the MIDI IN and MIDI OUT on the MFC-101 are bi-directional. I think that the MIDI IN on the Axe-Fx is also bi-directional. I don't think that the MIDI OUT/THROUGH on the Axe-Fx are bi-directional. You may need to verify that with someone. Since the advent of the Axe-Fx XL and the FASLINK connector, the MIDI sockets on the Axe-Fx may no longer be bi-directional. I don't know.
 
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