There have been many articles related to Synth DIY and other Electro-Music projects over the years, even today. But the pre-eminent period for this kind of project was in the 1970's when Electronic hobbyist magazines such as Practical Electronics (PE), Wireless World, Electronics Today International (ETI) and Elektor were at the forefront, publishing designs for the synth builder. There were even synth designs in Early Hi-Fi for Pleasure magazines. In the 80's projects became more computer based, but even here many MIDI and controller designs became available to Synth DIYers, often the output of Synth DIYers themselves.
- Electronics & Music Maker (E&MM)
- Electronics Monthly
- Electronics Today International (ETI)
- Everyday Electronics (EE)
- Hobby Electronics (HE)
- Home & Studio Recording (H&SR)
- Practical Electronics (PE)
- Practical Wireless (PW)
- Sound On Sound (SOS)
- Wireless World
- Elektor was available in many other countries with local names, such as in Germany France and Italy
- ETI actually started in Australia before the UK version was printed.
Anything maybe worth reading to learn about SDIY goes here. If a link is dead, you might find the site preserved on the Internet Archive's Wayback Machine.
- Nuts & Volts magazine downloads
- Eight issues of Modulus
- A selection of articles from Synapse Magazine
- Electronic Music Review, edited by Reynold Weidenaar and Robert Moog,
- Magazine, some here, search by directory.
-  An archive of many magazines, including Audio, Radio and Electronics magazines. An excellent resource including many magazine scans.