Battery powered MD & MNM

Elektron Gear Machinedrum
#1

Hi all!

I have seen people build battery powered digitones, digitakts & octatracks around the net and I am trying to mod my MD & MNM similarly (probably will have someone with more skill do it for me).
I am inspired by this video, since it doesn’t seem like too much soldering: https://youtu.be/DHk0Vw21Jps?si=FojP0iYrgYs-vxm9

So I opened up my machinedrum to see if there is enough room inside and there seems to be…

[Album] Opening uo my MD

Has any one done this before? What kind of components would you use? I am trying to get some expert’s opinion on this.

#2

Consider the availability and cost of replacement parts if something goes bad later due to the installation or the nature of batteries degrading over time. It’s the same problems people have run into with newer battery mod’ed Elektron devices but with more expensive and less repairable consequences.

Otherwise, I’m sure it’s doable if you already have the knowledge to modify something for battery power. It’s a matter of matching volts and amps plus a little soldering.

#3

I will come out of retirement for this thread (but only for a moment)

I have converted my mdmk2 to usbC using off the shelf parts, but I have not mounted them internally (yet)
Next step is my inserting the battery in the chain, which shouldn’t be too complex at this point.

I can only speak for the mk2 here, not a mk1, cause the mk1 is AC, and that introduces a whole different set of issues. From your photo library it appears you are working with an MK2. If you’re working with an mk1, forget it. Working with AC (mk1) is a whole different ballgame than DC (mk2)

It’s weird but not too weird, but all of my boards are red, not green….see vid below. Could be just different years/manufacturing runs.

The issue here is the MD (dunno about the MnM) is it’s a weird voltage at a lot of amps. 6v/3amp.
The digitakt is 12v/1a

12v is quite normal, 6v is not. 3amps is a HUGE power draw for electronics. 1amp is not a lot.

So what you will run into here is stepping down lipo batteries to 6v AND having enough juice to deliver for a worth while session time of a few hours… 3000mah battery at 3 amps is 1 hour of use in a perfect world

You can see you will need a HUGE battery. There’s not that much space in there.

Anyway….before you start going and destroying your MD, this vid helped me the most cause i got all the readings i needed before opening it up….

Best of luck. Just make sure you’re multimeter skills are up to par before you start wiring batteries to “next to irreplaceable” gear

3 Likes
#4

I’ll add that I’m tempted to just leave the battery external and perfect the usbc input instead, but I’m kinda willing to blow my shit up on the attempt to get an internal battery in there.

#5

okay… at 1st, youre not need so much space for putting in some li-poly pack. but! if you have no experience in soldering especially working with li-ion li-poly - it can be dangerouse.

what input voltage DC marked on your devs? if smthng like 12V then you’ll need 3 elements of li-ion polymer and BMS pcb - also called balance charging board.

li-poly batteries can be like stimorol chewing gum. but everyones forgot about it and thinks that only 18650 there are in this world )))

by the way i still cant understand what reason is to put in some batteries? why the manufacturer didn’t made it with it?

#6

Sell out. Where’s the pics?

#7

I dont wanna be responsible for blowing up someone’s shit, it from my testing so far, everything seems sound……

But the off the shelf parts are a USB trigger board set to 9v (which handles up to 5amps) like this:

IMG_0122
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Which is wired to a a BEC for a remote control airplane……which is basically a programmable buck converter to output 6v like this:

https://www.castlecreations.com/en/cc-bec-010-0004-00

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But that’s all I’m giving, I’m testing on an external MD psu, but so far, I’m getting a consistent 6v/3A from a 45w usb power brick…

Technically by USB specs, all I should need is a 27w brick, but it’s been a little weird there

#8

Yeah ….i bite my nails

#9

Works for OT mkI also then, hypothetically. The usb power brick is 5V or 9V?

#10

I told you I was gonna blow my shit up and not care…,
…so I’ve been going down the road……

#11

You playin with fire booowah.

1 Like
#12

I dunno what the OT requires, but usb c PD trigger boards are straight forward. Literally can put them in anything.

It’s the fact the MD requires 6v, which isn’t a USB standard, that I have to throw in the buck converter….

#13

I don’t have one, but I do know OT mkI requires 6V.

I think with a mkII monomachine this would be too risky for most people. MD is risky enough. But if it’s working that’s pretty cool doe.

#14

The digitakt requires 12v/1 amp.

You reall can just remove the barrel jack and replace it with a usb c 12v trigger board… Wire it internally the same way as the barrel jack.

#15

USB c PD doesn’t know 6v. That’s the issue I’m dealing with

#16

the trigger boards are all at set voltages?

#17

You can buy them preset or programmable.
The output is what you have to program.

If your device requires 12v, the board needs to put out 12v on the back. The trigger board knows what power to negotiate with the brick.

Programmable boards are usually a bit larger than fix voltage ones, but they are all small.

It’s pretty simple.

Here’s a vid to explain one with a programmable button….

#18

Other than the power board you fried, what was your parts cost?

#19

Yeah, it seems the MNM & MD (both mk2) have the same power reqs

Screenshot 2024-02-27 at 11.50.13
Screenshot 2024-02-27 at 11.50.131280×1708 331 KB

The MNM is my baby and I really don’t want to even open it up until I know exactly what I’m doing… That’s why I started with the MD. I am not nearly competent enough to do anything myself, so right now I am simply theorizing (put the MD back together and everything is working well).

I wrote an email to Robert Brandin, who is known for successfully installing battery packs in the DN, DT & OT. Here’s what he had to say:
"unfortunately no, I have those as well and between the lack of usable space inside and the fact that both machines have bizarre power requirements (especially the mk1 MD, you’d have to design a whole new power supply to make that one usable since in their infinite forward thinking they went with 6v AC) it’s just not feasible. 12v DC, or anything divisible by 4, is pretty easy to hit with off the shelf parts. Anything else I’d be worried about bodging together too many weak links. And I wouldn’t want to go experimenting on their most valuable machines without actually being a professional EE or circuit designer which I am decidedly not.

Sorry to be the bearer of bad news, it’d be awesome to give them a new portable life but given that there was a brief attempt to emulate the MD firmware in mame, my long term baseless prediction is maybe some day we’ll get an fpga emulation or something even wilder to get these things portable, usable, and accessible because right now they’re rare and only getting rarer and I’d be really nervous about screwing one up. I tried to revive a dead for parts MD (and got as far as contacting their old US repair tech to get tips) and then tried to reverse engineer the plus drive and in both cases… just too quirky and risky."

#20

I didn’t fry anything yet.

Cost right now:
Trigger board: 2$
BEC: 25$
Programmer for the BEC: 11$ (reusable )

Other than that…solder, wiring, and multimeter testing