[sdiy] History of SDIY?

[Rob Kam]

Unlike for the history of electronic music http://120years.net/, apparently
there's not much documentation specifically for the history of DIY
electronic music equipment. I have some questions, if I may.

How to define SDIY - it's not just exclusively synths, amateurs making
electronic music circuits as opposed to plugging together ready-made parts?
 
When did SDIY begin and how has it developed over the years? Especially
since the invention of semiconductors but before then should also be
included. What were the significant moments and who were the pioneers along
the way?

Bob Moog sold Theremin kits in the 1950s. Guitar pedals began development in
the 1960s. Before this there were guitar amplifiers with effects built in,
and earlier still people used magnetic tape. The PAiA FAQ states that the
1970s were busy, the 1980s were quieter, (with the hobbyists being
distracted by PCs) and that interest picked up again in the 1990s. PAiA has
been producing synthesizer kits since 1972. Electronotes started in 1972.
Various magazine articles by authors such as Tim Orr, John Simonton, Don
Lancaster, Craig Anderton, etc. give some sort of indication. The earliest
DIY electronic music instrument books seem to be from the early to
mid-1970s. 

How to distinguish what's SDIY from R&D? Obviously the pioneers and
inventors like Harald Bode and Kraftwerk had to DIY; does this get ignored?
Does it begin with the electro-magnetic Helmholtz resonator?