Waveform Magazine Project 2 - Gateway Oscilloscope - DIY Build
With the summer months on the horizon, we decided to take on a new series of modules or tools for eurorack. This months DIY build is the Waveform Magazine Gateway Oscilloscope; a cheap effective audio visualization tool for your modular rack.
This module is often referred to as “Project #2”.
As part of the DIY series from Waveform Magazine, the Gateway Oscilloscope (as we will call it from this point forward) is an inexpensive alternative to some of the more well known oscilloscopes on the modular marketplace today. One thing is for sure with any oscilloscope, not only is it an useful tool, but it is a lot of fun being able to see the waveforms that you are patching through your system.
Waveform Magazine? What is that?
Until recently, there has been little to no print form magazines that cover modular synthesis. One might be able to find an article here and there, along with a review or two, but there was never a dedicated publication available monthly. Waveform Magazine was the first to take this one and even though its in its infancy stage (only 3 have been released), it is slowly becoming the hot topic of the modular world.
WF Magazine reviews new gear, interviews articles, previews upcoming modules and even has a net DIY project in every edition. This is where the Gateway Oscilloscope was born. It was featured in the Fall 2019 issue of Waveform Magazine and is still currently available via their website. The cool thing about Waveform Magazine is that the first 3 issues were free. You heard right… Free! Starting with Issue #4, they will be charging for a subscription, and you can guarantee that we won’t be missing a single issue!
On with the build…
To start things off, we are going to keep this review and build guide kinda simple. Waveform Magazine has provided some great instructions via their website and these are accessible here. With that being said, lets get the show on the road.
At the core of the Gateway is the DSO138 mini manufactured by JYE Tech. This small portable oscilloscope has been on the market for awhile now and has been a staple to a lot of modular DIY’ers. The kit that we received had the DSO138 included, but Waveform offers a fully assembled version and a panel/PCB combo only version as well.
Upon receiving the Gateway, we noticed that the panel was a nice matte black. Being that this can scratch easily or show oil marks from dirty hands, we decided to take ours out and clear coat it.
The clear coat acts as a protectant and also keeps the matte black panel more scratch resistant.
A couple of coats later, we popped the panel in the oven on low and baked it for about 30 min. Removing it from the oven, we set it to the side and went back to the shop to start the build.
Waveform Magazine Gateway Oscilloscope - Time Lapse Build
There are several main parts to the Gateway kit. DSO138, panel, acrylic case and eurorack power board conversion PCB. Start by sorting all of this out into separate sections on your build space and then pack the acrylic case aside. Buttons are the only thing we will be using from the acrylic case package. As for where to start, that is up to you.
We started with the eurorack power conversion PCB since it had the most “parts” and were scattered amongst the kit. Before we knew it, we were done with the power board and it was time to get onto the main even.. the DSO138.
The DSO138 - Heart of the Gateway Oscilloscope
Start by unpacking the DSO138 from its box and take note that you will not be using everything you see. You can refer to these parts from the previously mentioned assembly instructions provided by Waveform. At first glance, the DSO build can be overwhelming. Thankfully JYE provided some assembly instructions that might require the use of a component tester to differentiate parts. You will want to test the LCD screen first by plugging it into a micro USB cable and ensuring that it powers on. After doing this, its time to solder.
Resistors, diodes, chokes, and all the other goodies are the first thing to mount. Use a fine tipped solder point on your iron to make sure you don’t ting other key components. Power pin headers, the power connector and a few other parts will not be used as mentioned earlier, so set those aside. You can view the DSO138 assembly guide here and we will provide the link at the bottom of this review/build guide.
Once you have everything soldered onto the main oscilloscope board, you will marry the LCD screen to the main board. They will fit exact due to the pin-headers that you previously soldered. Place the white buttons from the acrylic case onto the tact switches on the main board and then lay the Waveform panel over the top of the LCD screen.
Note: There is a protective film on the LCD screen that you will want to remove prior to panel placement.
Bring on the power!
Our power board is next in line to be mounted and its mounting is done by simply installing jack nuts on the front of the panel. This will hold the power panel in place as you get ready to solder the wires connecting the power board to the main board. Follow the diagram on the Waveform build guide for details on wiring.
Now that this has all been completed, its time to power on and test the entire module and then break out the clippers. We tested our modules power prior to any permanent mounting to ensure we didn’t miss a connection or power header. We accomplished this with the Synthrotek TST module; another great tool for any rack system.
The switches that were mounted on the DSO138 main board will have to be cut down for eurorack mounting as they stick out past the panel. Hopefully, at this point your Gateway is not smoking or sparking and is ready to be mounted.
Switch the oscilloscope to the on position and then using your clippers, chop the top 3/4 of the black switch off. Prior to mounting in your rack, the other switches will suffer the same fate.
Let's Get Patching!
Patching …the moment you have been waiting for! You have done it. You have successfully build the Waveform Magazine Gateway Oscilloscope. Now, how the hell do you use it? Usage is pretty simple. Plug an output from an audio source into the input, the output/thru goes to wherever you intended the input to go to. Watch the signal and adjust accordingly. That’s it.
Our Final Thoughts . . .
Oscilloscopes have been around a long time and they won’t be going anywhere soon, as they one of the most useful and cool tools around. The Waveform Magazine Gateway Oscilloscope is a cheap effective intro into the world of visualizing audio signals. With simple build guides and easy to read output, this one is a no-brainer to buy. We liked the aesthetics of the panel, complete with the Waveform logo and the ability to order a kit how we pleased.
Some of the cons of this module is that it might not be “enough” for some users. (its fine for us) and calibration needs to be done without the panel on. (we still need to go back and do this). Lastly, the matte black panels can be irritating to some if you don’t clear coat them; spend 30 extra minutes and take care of your panels. Another thing we had wished for was some sort of basic settings or instructions on how and what to set your new Gateway to. This would have helped the basic DIY’er and ease the stress of learning oscilloscopes.
In the end, the final word is that the Gateway Oscilloscope was a fun build with little if any setbacks. As long as one follows the build guides and BOM, you too will have one up and running in now time! Waveform Magazine has done a hell of a job bringing this kit to the public and we look forward to the next DIY project featured in the upcoming issues.
If you have questions about the build process or suggestions/feedback about this article, feel free to let us know by contacting us We look forward to hearing from you!
Until the next build …