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Hey,

I recently made a hack where I converted my ES2 into fully USB powered version. Is anyone interested in the details?

here's a proof: https://twitter.com/asterlabaster/statu ... 4483385346

I used https://www.pololu.com/product/2576 flyback, but probably any 5V to 9V should be OK, just pay attention to efficiency at max 1A current draw - there also exist converters like this but I wanted to have it more seamless.

MIDI works without any issues, the procedure is rather straightforward, however hooking 5V inside the case is a little bit tricky as pads that I soldered to are quite small.

I ran some tests with adjustable PSU and with ES2 playing some complex pattern with 80 Ohm impedance headphones I got:

0.31-0.32 A in standby (9V)
0.33-0.35 A playing with headphones hooked up (9V)

Some other observations:
6.5 V two battery bars
6.0 V one battery bar
5.6 V low battery warning
5.5 V ES2 dies

If you hookup boost-converter with 5V input voltage, it's pretty obvious that the current draw will be much higher once you step-up the voltage to 9V. From my very brief testing it turns out ES2 will draw around 0.5-0.6A from power supply. I still have to check how much current it will draw once the usb power bank drains a bit, safe to assume it wouldn't draw more than one amp, in general it should be pretty safe to power it from laptop USB port (which I do right now) or any powerbank, with some of them we I should be able to reach around 20-30h uptime (again, this is pretty back of the napkin) - much better than AA batteries.

Let me know if you are interested in the details.

Thanks

Great idea!

I currently like to power my E2S with a 5v USB powerbank… I guess a 5v to 9v cable (with a converter) would be ok for me, something like you have linked, or this:

https://www.amazon.de/MICGOGO-Einstellb ... WSZ8TYQYVK

I don’t know if I understood „just pay attention to efficiency at max 1A current draw“... does that mean that the 9v output should not be more than 1A? Or the input on the 5v USB connection (powerbank)? The cable in my link has 2A on the 9v side, is this too much?

The efficiency part only makes sense if you have this information available. Usually when you buy ready converts (like the one you linked) they rarely tell you about the efficiency.

When you buy electronic modules (like this https://www.pololu.com/product/2576) you'll get a lot more information, including the efficiency: https://a.pololu-files.com/picture/0J50 ... 298329adc2


the lower the efficiency at 9V out the higher the loses. That doesn't matter much when you power from a laptop, but can make a difference when you power from power bank.