Koma Elektronik Field Kit & Field Kit FX



Mannequins Just Friends in Spill mode, with 6 individual outs to Nonlinear Circuits Cluster, summing into CV In for the Field Kit DC interface, set to PWM. Solenoid wedged into an inverted cardboard box resting on top of Oriental Wavedrum set to voice 039 Flamenco Castanet & Tap, into Ableton Live with Waves L1 Limiter and Musical Entropy Spaceship Delay set to Dub Drums.

I can vary the rhythm with the knobs on the Cluster and the knobs on Just Friends in all sorts of interesting ways.

Solenoids are way cool!


I put the Field Kit DIY option together weeks ago, finally last night got around to playing with it. Finally gave me the impetus and extra mixer to try no-input mixing. Boss “Metal Zone” in a feedback loop from the aux out to one of the inputs, LFO at audio rates to another input (Seems to cause some FM in the pedal at the right settings!), master out through a Dimension-C knockoff and Eventide Space.

The Metal Zone seems like it has particularly significant phase-shift compared to other distortion or overdrive pedals I had on hand, made it much easier to create controllable oscillation. The little mini-equalizer helps too.

next time I should record a bit of this :slight_smile:


I can’t remember if it was discussed here or elsewhere… but I finally got around trying to power the Field Kit with a 9V battery… I soldered myself a simple solution out of a battery clip and a 2.1mm barrel connector… and… it doesn’t work.

I was really hoping for this to work, but the battery doesn’t seem to have enough juice for this. I can’t even get all the LED to light up properly. If anybody got that to work, let me know. Maybe putting multiple 9V batteries in parallel (not in series) might do the trick.


Modulargrid says that the Field Kit wants 850ma of 12V+ in Eurorack mode. A 9V battery puts out about 50ma. So you would need 17 9V batteries in parallel and they probably wouldn’t last very long. (Does anybody sell rechargeable 9Vs?)

Recent vaping adventures (it’s medical, folks!) have introduced me to the wonders of the 18650 lithium ion rechargeable battery. Seems like a battery pack made up of those types of cells might work better?


yes, just like I imagined… I think I was deceived by somebody saying that it worked, but I guess I have either imagined that, or somebody was making stuff up.

that might work indeed. I also need to look into video camera battery packs. I remember we used to power anything with those…


The power adapter it ships with is 9V 2A. I’d be interested to know if something like this would work:



That should work just fine but it is unfortunately discontinued. However, searching for “external multivoltage laptop battery” will yield similar results.


Oops, hadn’t realized. Still shows up as in stock at Amazon’s Canada store.


Out of the box, it will in fact not work. I have one, I tried it.

The Koma input is tip-negative ring-positive. You’d need to fab up an adapter, in the very least.


Some of the external batteries come with a large number of tips for different sizes, but I suppose they don’t provide switchable polarity like old multivoltage AC adapters did, because laptops are always tip-positive? Or maybe some other battery has switchable polarity?


Nope. Tried, looked, no dice.

I know all this only because Koma shipped mine originally with a Euro 220v adapter, not the 110v adapter.

A guitar effects type wall wart with tip- ring+ connector will work though, if the barrel is the right size.


That should be a quick fix though. It’s just two wires, also You’d probably have to solder a 2.1mm barrel connector onto the wire anyway, since most laptops don’t use that connector.


Yeah, that’s what I was saying about changeable tips earlier though, many external batteries come with a variety of interchangeable barrels so you can use the correct size.


Oh then I misread the post.


Given the need then for centre-negative, thoughts on something made for guitar pedals working? Like the Pedaltrain Volto maybe:



Might be worth a try, but two sentences on the product page gave me pause for potential concern:

• Not intended for high-draw digital pedals
• 2000 mA is a measure of peak output not recommended usable capacity

I guess for the Field Kit alone, this shouldn’t be a problem, but I wouldn’t use this battery to power a eurorack case.


The advantage might be that since it’s intended to be used for guitar pedals, it might be quieter and more stable than those made for laptops. Though batteries usually don’t have problems with ripple noise and the likes.
Anyway I don’t think the Field kit will reach a peak current draw of 2A so it should be fine.


Strange, this is what the KOMA reps say on the Kickstarter comment thread:

@Larry no harm is done to the unit by powering it with a 9V battery. Maybe if you start to use more features like the speaker it just cannot give the mA’s needed. etc. Make sure to check that the battery doesn’t get overly warm or anything, but else you are good to go :).

I just ordered a barrel plug adapter, and was looking forward to using it in the park. =(


So that’s where I had read about it. Hmm… need to check my battery, but I’m pretty sure it was a brand new one.