Hi Claquoss,
I just built a modified version of the 8 step sequencer. It took a while and was something of a challenge to build, but not because it required any particular knowledge beyond how to solder stuff. Just that there was a lot to solder, and a lot of figuring out how to get wires connecting point A to point B in an efficient way without interfering with anything else. The original version is simpler than mine although I think there are some errors in the way it’s shown — the way the regulator connects to the Arduino and the relative placement of the pull down resistors and diodes on the input jacks — but those are covered in the 8-Step Arduino Sequencer topic.
You can go even simpler by building a Baby 8 sequencer. It’ll have less functionality than the LMNC 8 step but would be less complicated to build.