I built a thing.
This is a DSO 138 Oscilloscope kit. I assembled it last night, and to my shock and amazement, it works!
I got the kit from HobbyKing, but it's almost the same price at Amazon. The kit was awesome, with fantastic documentation. I think it might have been missing one resistor, but it's possible that I could have dropped the missing one. (Cluttered workbenches like to eat parts.)
Now I have to learn how to use an oscilloscope. I'd also like to make or 3d print a case for it.