Tired of Arduino, how can I get started to build hardware synth?

There are some good books...

Delton T Horn's Music Synthesizers a manual of design and construction. http://lucmorton.com/lucstuf/pdf/Music%20Synthesizers%20-%20...

Miller Puckette's theory and technique of electronic music http://msp.ucsd.edu/techniques.htm

Dave Bensons music a mathematical offering: https://homepages.abdn.ac.uk/d.j.benson/pages/html/maths-mus...

Here is a list of other good reference books: https://sdiy.info/wiki/Synth_DIY_books Also, if you don't mind digital - have you seen the daisy ecosystem?

https://www.electro-smith.com/ https://github.com/electro-smith/DaisyWiki/wiki

They have built a DSP library with a lot of the basics, there are plenty of example projects, and a supportive community.

https://github.com/electro-smith/DaisyExamples https://forum.electro-smith.com/

I don't build synths.

If I did, this is where I would start:

https://archive.org/details/electronic-music-circuits

There is a link to download the PDF below the viewer.

Hard copies are more expensive than most books but less expensive than many analog synths.

Good luck.

*Edit*

Came back to say, I would also consider Eurorack simply because that would simplify decisions about form factors, power supply voltages, manufacture, testing, etc. during design.

If you are interested in analog synthesizers then a lot of the schematics and explanations of the circuits were published in magazines in the 1970's. I think ElectroNotes was one of the premier ones, but Radio Electronics, Polyphony, Elektor and others published circuits as well, with explanations of how they worked. Here are some leads:

https://paia.com/polyphny/

https://archive.org/details/radioelectronicsmagazine

https://blog.adafruit.com/2022/02/07/70s-electronic-music-ma...

https://worldradiohistory.com

https://worldradiohistory.com/Elektor.htm

There are still some kits available as well to learn by doing:

https://paia.com/p9700/

You can also get schematics for some classic synths:

http://www.arpodyssey.com/schematics.html

https://archive.org/details/arp_ARP_Quadra_Schematic

https://archive.org/details/ARP_Solina_Schematics

https://moogfoundation.org/schematics/

I initially started out with music from outer space as an educational resource and recently dug through the classic of electronotes, but if you're looking for videos with a lower barrier to entry I'd recommend: https://www.youtube.com/c/MoritzKlein0 (perhaps also https://www.youtube.com/c/TheAudioPhool )

I think this book is quite a good introduction to get you started: https://www.oreilly.com/library/view/make-analog-synthesizer...

Use teensy instead.

This is a good youtube channel to learn diy synth stuff https://www.youtube.com/c/MoritzKlein0/videos