vintage parts

Back in the day, it wasn't uncommon for engineers to build their own equipment.  It was very common to see electronic parts manufacturers advertise their products in recording magazines.  The word "engineer" today doesn't mean what it did back then.  Today everyone will label themselves as a recording "engineer," but most have absolutely no actual electronic engineering background to support their audio engineering profession (or hobby).  In the 40's and 50's - it was usually one in the same.  For example:  If you ask an audio "engineer" today to describe to you signal flow of any mixing console in a coherent way, they'd have no idea where to even start.  "Yo bra, this sampler goes into my pro-tools rig and out my monitors." Sad...