This post will describe the design and DIY build of a 1MHz, a 10MHz or a 100MHz differential probe.
In 2017, my buddy in crime Bud and I (well, mostly Bud) build a DIY X10 100MHz probe that has been very popular because so many other makers build it, or even changed it to their liking, We know of a 1x and a 100x design modification. Our earlier design was described here:
Unfortunately, that 2017 design has some hard to get and rather expensive parts, especially the Opamps and also some hard to get capacitors.
In early 2025, Bud has been looking into making the probe easier to build and make some needed improvements. He investigated the whole concept again and came-up with a main probe PCB that can be used to build a 10x 100MHz, but also a 10Mhz or a 1MHz version, that are each less expensive to make. The other constraint on the earlier design was the external power supply. Now that we have USB-C PD capabilities, he added a number of power options that can be added to the probe to your liking. Another main issue that he wanted to address was a 3D printable housing and making the probe slimmer so it's easier to hold while probing around with it.
There are some more improvements and refinements and if you're interested, you can follow along his efforts here:
Bud is now in the final stages of verifying and testing everything, and when he's done, I will add the information here also and provide the BOM and Gerber information in a new Github project.
If you're looking to build a probe, all I can say at the moment is to stay tuned for a little while longer. It will most likely be finished in September of 2025, so if you can hold-off, I recommend you do so.
