Midihub no longer working with power banks

Midihub Support
1

Hello,

I have a configuration with a keyboard, a mixer, a Bome Box, the Midihub, a sound module, all working with two 18’000 mAH Powerbanks from Revolt (see attached picture), but recently, after having operated that way for more than an year, the Midihub just turns off unexpectedly, sometimes affecting the Yamaha Mixer which is attached to the same Hama USB Hub.

I have replaced cables, exchanged the Revolt Powerbanks, even tried with a new Power Bank from another brand dedicated to the Midihub, to no avail. At the moment it takes just a few seconds until the Midihub turns itself off and the power bank’s display shows that there are no more devices attached.

The Midihub can hold its power when attached to the USB port of my PC, at least longer than when attached to the power banks. But this does’t help. I want to be independent from outlets.

I bought the Midihub Oct. 24, 2022. What can I do?
Alex

MIDI Audio Connections.pdf (4.9 MB)

2

As we’ve seen some other units’ power slide switch fail, maybe this is some early stage of the failure. Try sliding the switch back and forth multiple times, to try and get the internal contact surface cleaned up, and see if that extends the ‘on’ duration. There’s some electronic contact cleaner sprays out there, some users had success with that, ultimately replacing the switch would be possible too.

Let us know if messing around with the power switch helps change the current behavior.

3

Sorry, Alexander @HunGrYforMuSiC, this keeps niggling me:

given the flow (from diag1 in your pdf) is

  • Revolt → Hama Hub → {Yamaha AG06 || Midihub}

how can “Midihub turns off” lead to “Yamaha affected”?

To my mind, “Midihub turns off” :heavy_plus_sign: “sometimes Yamaha affected” implies the issue is upstream of the two devices.

As an aside:

Whenever I have had “Midihub switches off under Powerbank” issues, it has always been the Powerbank, not Midihub:

  • The problem arises (I think) cos Midihub makes such a tiny demand that some powerbanks just switch off, so

  • the issue solves itself when I attach something else like a Keystep to the bank,

  • then the powerbank stays busy and MH stays powered

Thought I’d mention it, but I guess if AG06 is only “sometimes” it’s probably unrelated

4

Hi Giedrius, thank you for your answer. I don’t think it is a contact because the Midihub works when powered from my PC. I have swiched it on and off many times without removing the cable from the Powerbank, and it powered up again, but only for a few seconds.

5

Hi resonotter, the Yamaha and the Midihub are powered from the same power bank and in between is the Hama USB Hub. I believe that in the moment the Midihub dies there is some repercussion back to the power bank and that’s why in some instances, the Yamaha’s power went down too, as the power bank stopped delivering current in that moment.

6

Ok, this made me think Midihub turns off while powered by a PC.

I can’t think of anything on Midihub’s side that could affect power in such a major way, it’s all very simple and very linear, with no ways to draw more power than necessary.

You should try and measure the voltage levels in your system, if your set up is not able to provide 5V to the USB devices, they may turn off.

One more idea - make sure you have no accidental MIDI OUT → MIDI OUT (or MIDI THRU) connection between devices.

1 Like
7

Three Points to consider:

It worked until recently.
I have checked with 3 power banks, and one of them is brand new.
Moreover, the Yamaha Mixer surely needs more power than the Midihub, and has no problems with either of these Powerbanks.

8

You should measure the voltages at the USB connectors when it’s working fine and when it’s not working.

9

OK.
I’m not a electrician. How can I measure the output and at the same time connect the midihub?
Which device is needed for that?

10

Some power devices play havoc because they are meant for fast charging instead of consistent power.

This is what I used to check USB power.

2 Likes
11

Back to the comment about MIDI thru paths. If you disconnect all MIDI cables from the MidiHub, does it still have a problem? Maybe a MIDI loop is confusing MIDIHub causing it to crash.

12

I ordered the USB multimeter UM120
USB Multimeter UM120
and measured the voltages.

The Midihub needs about 49 mA, which is quite a lot compared to my Yamaha AG06 Mixer (44 mA), and to the BomeBox (13 mA). I only use very short UBS cables (20 cm) except otherwise stated.

I first checked with the xtorm 20 W Power Bank which has a Voltage of 5.165 V. When I put a HAMA UBS 4-port with a short cable (15 cm) in between its 5.11 V. When I attach my Yamaha AG06 Mixer it remains 5.01 V. However, when I use a switchable HAMA UBS 4-port with a longer cable, its 4.95 V, and with the mixer attached, 4.67 V.

I think this is not enough voltage although the Yamaha mixer is much more forgiving.

The Revolt 100W 12V/5V powerbank is even worse. It has 5.06V with nothing in between, goes down to 4.99 V already with the short USB Hub. In the end, it also reaches 4.67 V.

This is certainly not enough power. I bought 2 Revolts to power 12 V devices and 5 V devices. I don’t use these anymore for 5V devices, also because the 12 V outlet produces noise in the USB 5 V outlet. This is a problem when you also have USB Audio on the same cable.

Strangely enough, my PC front USB outlet delivers only 4.9 V when directly connected, but this connection held. It must therefore be something different that caused the outage.

By the way, the MidiHub did not switch itself off anymore in the tests after these 2 weeks of rest. This is something I cannot explain.

After all these troubles with my hardware devices (especially with the BomeBox when switching between Wifi mode and standalone mode) I have decided to get rid of all of them and setup a system with my iPad, Cubasis 3, Mozaic MIDI processor and AUM. Hopefully this will be less of a hassle.

13

How do you have the BomeBox powered?

14

Also with powerbanks, because I want to be independent of alternate current.

I started off with Midihub, then added the BomeBox, which was a huge improvement in terms of functionality. Now I’m making another leap to Mozaic, which is even more flexible because it is a programming language that can handle MIDI and clock data. And the iPad is made for independence from outlets, and therefore much more reliable, in my opinion. My first tests are very promising.