Mutec 3+ USB Midi Issues

[Eddiechilli]

Dear Community,

 

I have been reading audio forums for years and should thank everyone for their contributions that have made my listening so good.

 

out of need and desperation I have shown to write my first post. Maybe it will help other users.

 

January I bought a Mutec 3+ USB from Thomann. 

 

In my view this device is ice is one of the best I have ever put in the chain and lived up to all the reviews and opinions.

 

Problem is that it is hardly working. I have a Mac mini late 2012 with 10.13 on it as the main digital listening source. The Mutec is sometimes seen by the Midi service most often not.

 

So I have tried a lot of fault finding:

 

Two other macs

USB 2 vs 3

USB c

Cables

Power

Different OS (Mojave vs Sierra)

boot sequence 

factory resets

 

For some reason the Mutec disappears of the midi and will not come back with any certainty. Then after all the methodical switching it will just pop up if I move the USB to a machine or port that did not work minutes before.

 

I had a long dialogue with Chris at 

Mutec (CEO) and they could not help. 

 

This device sounds so great I do not want to scrap it. Has anyone solved this problem before.

 

I have Audirvana, ITunes, Pure Music etc but the problem seems to be at the Midi, before the applications.

 

chain =

Mac > Mutec > minidsp 4x10> 4x power amps > 4 way speakers

 

the Mutec locks on (blue light), sometimes does not get the right bit rate, sometimes does.

 

Your wisdom and experience gratefully received

 

Eddiechilli

[One and a half]

Chris would have mentioned that the USB front end current consumption on the USB input on MC-3+USB is a little on the high side? I can't remember now the exact number, but it is more than 200mA. A search here may reveal the exact amount. Even though the AC power is on, and you've tried USB3/2 and USB C each one has enough current capability, there's still a problem.

 

A suggestion is to supply the 5V not from the computer, but from an independent power supply. Although the MC-3+USB has galvanic isolation, there's still some benefit to use a clean 5V from AQVOX (for example), where the supply is some 1000mA. 

 

The USB ports on the Mac are also shared with other devices internally, so each one robs a little more power every time. It's also possible that the USB port can be forced off due to energy saving schemes.

[Eddiechilli]

Thank you for taking time to offer advice.

 

Chris had advised the MC 3 needs 350ma

 

i have tried a powered USB bus.

 

A series power monitor then the MC is pulling 250ma (suggests a problem). Because of the USB A connectors of the power monitor I can only place it at the Mac end before the cable and of course the monitor is self will have resistance (0.01 ohm specified). However the usb bus on the Mac can deliver 430ma according to DDM. Even so I have tried it on usb3 pushing more than 1a and it does not work.

 

yesterday I got it to play, I left everything on overnight and this morning the MC3 is not in the Midi. I have reset it, nothing, reboot, nothing, different port, nothing, disable everything sucking bus power e.g. Bluetooth, nothing.

 

So frustrating.