MIDI output voltage: WIDI Master is getting hot

teejoo said:
(Sorry to go off topic, but) Can you power a Morningstar MC6 from the midi port?
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Phantom power the MC6 via MIDI pins 6 & 7. No idea how since FM3 has 5-pin MIDI.
Use standard pedal 9V connector instead. (center Negative)
 
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I built a connector but the WIDI Master stays off.
Does MIDI Thru does not let the power through? ...
My signal is: FM3 MIDI OUT > BOOS RC-5 MIDI IN > BOSS RC-5 MIDI THRU > Custom MIDI cable with 220 ohm resistor > WIDI Master
My cable is working, checked the functionality with another USB interface and MIDI IN/OUT worked :( ... But not the voltage, i guess ..

This topic gave me real headaches .. why is the FM3 wrongly built? I don't get it.

EDIT: I rebuilt my MIDI signal flow ... now, i'm going IN through my RC-5 and directly OUT from my FM3 and it seems to work!
 
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MrPond said:
I built a connector but the WIDI Master stays off.
Does MIDI Thru does not let the power through? ...
My signal is: FM3 MIDI OUT > BOOS RC-5 MIDI IN > BOSS RC-5 MIDI THRU > Custom MIDI cable with 220 ohm resistor > WIDI Master
My cable is working, checked the functionality with another USB interface and MIDI IN/OUT worked :( ... But not the voltage, i guess ..

This topic gave me real headaches .. why is the FM3 wrongly built? I don't get it.

EDIT: I rebuilt my MIDI signal flow ... now, i'm going IN through my RC-5 and directly OUT from my FM3 and it seems to work!
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Glad you got it working!
The 220ohm resistor will limit current from the FM3 to the WIDI Master.
However your Boss RC5 already has a current limiting resistor in it.
So if you add another resistor to the Boss pedal midi out, then the widi master won't get enough current to turn on.
You only need the resistor on the Midi Out of the FM3 when directly powering the Widi Master.
 
Just tries the Yamaha MD BT01 on the FM3, unfortunately it heats up immediately after pluging in..
 
NHD said:
Just tries the Yamaha MD BT01 on the FM3, unfortunately it heats up immediately after pluging in..
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Does that work for anyone with MD BT01?

I just sold my kemper stage and gonna buy a fm3 and I really need it to work.
 
Electrically speaking the FM3 is not making any current it is only suppling a voltage. Current is made by the load applied to a voltage which in this case is the WIDI device. IMHO the WIDI device and design should be taking care of limiting or properly dissipating the heat (if it’s truly at a level that will damage the components used) being created.

Admittedly I only just read through most of this thread. So I maybe missed something along the way…BTW, love the thought and DIY ingenuity of what I read to alleviate this issue. That’s what I love about electronics. There’s usually always a way to fix a bad design or poor quality components.
 
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I tested Yamaha BT-01 yesterday. It was 3 hours. Everything worked without bugs. And it wasn't all too hot that you can't touch it. There is no reason for me to worry.
 
Fractal should (if they haven't already) put a little warning in the docs. If a current limiting resistor is part of the spec and they omitted it; a heads up could prevent some headaches.
 
stub said:
Fractal should (if they haven't already) put a little warning in the docs. If a current limiting resistor is part of the spec and they omitted it; a heads up could prevent some headaches.
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I understand that this is not Fractal's problem. As it has been said before, both 3.3V and 5V are acceptable MIDI standards (the 1983 MIDI 1.0 DIN Electrical Specification states 5V, and included 3.3V at Revision 1.1 in 2014)

It is the responsibility of the manufacturer to ensure that his device feeding from the MIDI connector can support both voltages without overheating. Most of them can support them, it seems like some bad designs don't.

There are countless devices supplying 5V at its MIDI output and I've never seen any with a warning label, because it is a standard since 1983

Or perhaps these bad interfaces are the ones that shall put a warning saying "This device does not comply with MIDI Standard 1.0 DIN Electrical Specifications. It can only be powered with 3.3V. Warranty voided and risk of fire or injury if powered with more than 3.3V"

Talk with the manufacturer of your product and return it if it overheats abnormally when powered with 5V, because it must be defective or poorly designed.
 
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Piing said:
I understand that this is not Fractal's problem. As it has been said before, both 3.3V and 5V are acceptable MIDI standards (the 1983 MIDI 1.0 DIN Electrical Specification states 5V, and included 3.3V at Revision 1.1 in 2014)

It is the responsibility of the manufacturer to ensure that his device feeding from the MIDI connector can support both voltages without overheating. Most of them can support them, it seems like some bad designs don't.

There are countless devices supplying 5V at its MIDI output and I've never seen any with a warning label, because it is a standard since 1983

Or perhaps these bad interfaces are the ones that shall put a warning saying "This device does not comply with MIDI Standard 1.0 DIN Electrical Specifications. It can only be powered with 3.3V. Warranty voided and risk of fire or injury if powered with more than 3.3V"

Talk with the manufacturer of your product and return it if it overheats abnormally when powered with 5V, because it must be defective or poorly designed.
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I've plugged the CME WIDI Master dongle into a Helix, Quad Cortex, FM3, Strymon Conduit, Morningstar ML5, BluGuitar Amp 1 and Axe-Fx 3.

Out of these the FM3 is the only device that caused it to overheat. I built a dongle with a resistor installed and that solves the problem.

So to me this is absolutely something Fractal should have fixed on their newer iterations of the FM3. The Axe-Fx 3 does not seem to suffer from the same issue.
 
Piing said:
I understand that this is not Fractal's problem. As it has been said before, both 3.3V and 5V are acceptable MIDI standards (the 1983 MIDI 1.0 DIN Electrical Specification states 5V, and included 3.3V at Revision 1.1 in 2014)
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I had inferred from what was shown earlier in the thread that a 220 ohm current limiting resistor is part of the official MIDI spec for the sending (MIDI OUT) device.

Fractal could add a warning: "The MIDI 1.1 Spec requires a MIDI OUT circuit to include a 220-ohm, current-limiting resistor. The FM3 has no such resistor in its circuit. If you plan to power an external MIDI device from the MIDI out port itself, you may need to add an inline resistor via a a homemade cable, or consider purchasing the new FAS "fire extinguisher" MIDI adapter."
 
stub said:
I had inferred from what was shown earlier in the thread that a 220 ohm current limiting resistor is part of the official MIDI spec for the sending (MIDI OUT) device.
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Could you show where this was stated as part of the MIDI spec because it is a backwards way to go about design?

The problem here is confusion over the primary understanding of the nature of the movement of electrons and how thermal particulars are created. Take a PSU. It has a voltage spec and a current handling spec. Meaning it provides a voltage potential and the device(s) connected should not create a load (current) that exceeds the amount of current the PSU is rated. Which is mostly depended on the thermal handling of the components that are used in the PSU. So it is the responsibility of designer of a product to use a PSU that can handle their device or the end user who is using a generic PSU to make sure what they connect doesn’t exceed the PSU’s rated current handling.

Where I would say the FM3 would be in error is if its MIDI interface was unable to handle the thermals created by a MIDI device connected and fail. And there’s the rub, MIDI has been around so long and I have connected (with cable) tons of devices together without ever having a thermal issue. The WIDI device has an added circuit that makes it wireless and also is made to be small and inexpensive. This is usually the recipe for design problems. Not normal MIDI to MIDI connections. In fact cable lengths have been an issue with corrupted data and this is where 5 volts would be a bit more desirable.

So what is FAS’s stance on this?
 
stub said:
https://mitxela.com/other/ca33.pdf
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After reading the section it appears the 3.3v spec is still a bit convoluted in regards to mixing 3.3 volt and 5 volt devices and if I was designing a product to be a go between I would make sure it was ubiquitous. Because from what I quickly ascertained there’s more to it than just putting a resistor in series to be completely adherent. I don’t doubt it probably is solving the excessive heat.

I wonder if part of FAS making the FM3 more 5 volt compliant is because it is a floor unit where long cable runs would be more common. I admit while I know a good bit about electronics there is always a myriad of considerations involved with designs, especially when “Standards” are involved, more so changing and evolving standards. I’ll bow out of this one. I guess I find it hard to believe that the FM3 is not compliant in some industry nominal way.
 
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