I had been hearing a bit of buzz about the DSO138 Digital Oscilloscope, and I wanted to make a demo video for the AI003¬†Looping ADSR Envelope Generator DIY Kit, so I figured I would give it a shot. I already have an older Tektronix scope that I love on the bench, but I realized that I could add this Cheap Eurorack Oscilloscope into my system and could put it next to the module I was demo’ing.


I bought the mostly pre soldered SMD kit for $25. There were still a few SMD resistors to solder, and then a bunch of through hole parts. The thru hole resistors and caps and other parts were all in one bag, so I had to sort them, which was a bit of a pain, but not too bad. You will want a multimeter though. Otherwise it was a very simple build. I added an 1/8″ input, which was easy as there are extra ground pads and an extra pad for the + of the BNC input, so I got to keep both inputs which was nice. It is mounted to two 2HP blank panels via spacers, which is what I mounted the 1/8″ jack to.


The scope itself… It is good eye candy. There’s just one trace and the signal is pretty noisy, and maybe it’s just me, but I end up accidentally hitting the power cycle button more than I would like. Other than that – it is fine for a cheap eurorack oscilloscope. It won’t replace my Tektronix any time soon, but it will serve me well for doing demo videos, and if you just need a scope for approximate testing and/or eye candy, at $25, it’s going to be hard to beat.

I grabbed a small piece of strip board in order to add a euro connector. It’s pretty simple, just a 10 pin euro connector that then goes into a simple LM7809 to hold the power to 9V, and then the ground and +v from Lm7809 goes to the following points on the board.

The 9V arrow points to the single 9V input pin of the pair, there is a plus sign next to it on the PCB – don’t do the other pin! User your multimeter and do a connectivity check before hand to make sure.

The mA draw is 120mA on the positive rail, there is no negative rail, so no power draw there.

Here is the schematic and diagram: