SEQTRAK MIDI controller power - Sand, software and soundSand, software and sound

In my last post about connecting a MIDI controller to Yamaha SEQTRAK over USB, I expressed concern about power draw. Measurements show that my initial concern is unfounded.

I pulled out a trusty Klein Tools ET900 USB Digital Multimeter. For testing, I plugged my two MIDI controllers through the meter into the USB-A port of an HP OmniDesk PC, assuming that the PC would provide a solid 5V USB power source.

Current draw is not as high as I expected. Of course, plugging a MIDI controller into SEQTRAK will drawn down the SEQTRAK’s lithium ion battery at a higher rate. Still, an additional 100mA to 200mA is not a big load.

Here are the test results:

    Novation Launchkey 49 mk4
        0.18A @ 5V
        Power = 0.18A * 5V = 0.9W

    Arturia Keylab Essential 49 mk2
        0.10A @ 5V
        Power = 0.10A * 5V = 0.5W

The current draws are 180mA and 100mA, respectively.

I also measured the SEQTRAK powered via the USB-A port:

    SEQTRAK
        Charging:  0.11A (110mA)
        Operation: 0.44A (440mA)

Yamaha spec the SEQTRAK in the following way:

    SEQTRAK battery
        Battery:           7.6Wh
        Power consumption: 6W
        Battery life:      3 to 4 hours

If I plug the operational current (0.44A) into the standard DC power equation:

    Power = 0.44A * 5V = 2.2W
    Estimated life = 7.6Wh / 2.2W = 3.45 hours

we see that Yamaha’s estimates are bang on: about 3 to 4 hours of continuous operation.

TalentCell 12V 6000mAh battery pack

Using a conservative 200mA additional draw for a MIDI controller, I estimate battery life, thus:

    Power = (0.44A + 0.20A) * 5V = 3.2W
    Estimated life = 7.6Wh / 3.2W = 2.37 hours

Good enough for a short one hour gig; anything longer would be safer on external power. My TalentCell (Model YB1206000-USB) has a USB-A port and could do the business.