After having started experimenting with my new electronic percussion kit I quickly started musing about situations where I could participate in jams and sessions. Since besides the social aspect that obviously is the best way to learn and make progress! Pretty soon one of the major drawbacks of an electronic drum or percussion device got obvious: you need electricity!

This certainly is not an issue on stage or in an exercise room. But what about outside? That is a typical use for drums: nature, beaches, evenings in parks, not to mention the legendary drum session at the beach in Valle Gran Rey on La Gomera at sun set…

That is why I decided to get a battery pack for my drum! Fine. Great plan. That is, actually, not fine, since it turned out to be not that easy to find a battery that combines a few requirements I had in mind…

  • small weight and dimensions (“portable”)
  • hassle free (weather and fiddling ’round)
  • powers multiple devices (drum, loudspeaker, headphones, smartphone)
  • reasonable capacity (“a few hours”)

Ok, come on, smartphone? I mean really? Well, sounds odd, but isn’t a smartphone the logical choice today when it comes to background music and stuff? Yep, I too owned a few “mp3 players” (mainly used to play “ogg vorbis” tracks instead of the questionable mp3 format…). But that was quite a while ago…

All of this sounds as if one needs a full ranged electric power plant or at least a serious switch board. Simply because of all the different devices to consider. But fortunately there are some de-facto standards that got established. One is that more and more electronic devices can be charged using a USB cable, which in turn means they all require the same power supply: 5V DC. And then there are electronic music devices which apparently use an own industry standard: a plain 9V DC jack. Great! So I was looking for a battery pack that offers 5V and 9V at the same time, that should get me going. When looking through the current offers one thing becomes obvious: the market moves towards “power banks”! Those are sleek battery packs able to refresh the often poor batteries in the ever present smartphones. What a surprise. They are everywhere. And some of those, some of the more advanced ones at least, even offer an additional DC outlet. And some of those rare ones even allow to chose the required 9V. So I had a match. Three specific products were for purchase online. After an annoying intermezzo with the failing delivery of my personal favorite I settled with my second best choice which turned out to be just right. Except for one little annoying detail: the device came with a series of adapters for the DC outlet which is great. But apparently the producer was completely unaware of the fact that electric current, specifically the DC version, comes in two flavors: with reverse polarity! It turns out that the de-facto standard for electronic music devices is in contrast to that of all other electronic devices! So I had my sleek battery pack, adapters for hundreds of different connectors. But unfortunately the device did not offer any means to reverse the polarity! Which in turn meant that I cannot operate my music devices!

Needless to say that my attempts to contact the producer were never answered… So as often I was on my own. But instead of sending back the battery pack (can you actually return unboxed batteries?) I decided to simply “fix” the issue at hand. So I took the DC connection cable and consulted my local electronics parts dealer, purchased a few spare parts to solder a solution myself. A welcome motivation to pay a long overdue visit to Hamburg’s Attraktor maker space, since my private soldering station somehow never got returned to me after I gave it to someone really in deep need to finish a project of his… And today, after purchasing a few additional shrinking tubes I finally managed to get the cable finished! I placed a pluggable connector in the middle of the cable which allow to reverse the electrical contacts. So I can use the cable in “standard mode” or in “music mode” 😉

A first try resulted in a frustrated “WTF!”. But after realizing that I had accidentally plugged in cable to the DC input of the battery pack instead of the output I finally was able to start my drum with it! heureka! So here some pics for those interested in it: