Here are my favorite links for DIY building , resources and info:

 

• https://buildyourownclone.com

• https://www.jlmaudio.com - Tons of parts & kits!

• https://www.thonk.co.uk – Eurorack & other synth stuff

• https://www.adafruit.com  - amazing site – lots of kits and parts

• https://www.instructables.com – very good instructional site

• https://www.mammothelectronics.com/collections/effects-pedal-kits

• https://www.crowdsupply.com/audio-builders-workshop/abw-metronome-and-low-pass-filter-kits

• https://www.electro-smith.com STMicro based kit

• http://thatcorp.com/pedals/index.html THAT Corporation Pedal Page

 

• https://www.minidsp.com  MINIDSP / DSP4YOU   A variety of small and large kits and products for audio signal processing and communication

• http://www.freedsp.cc   FreeDSP Open-source digital signal processor family for the do-it-yourself community.

• https://www.rebeltech.org/product/owl-modular/ OWL Modular            Open source programmable digital audio eurorack module based on an ARM Cortex M4.

• https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/sharc-audio-module.html   SHARC Audio Module – professional DSP project board, extensive wiki support

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• Misc Hardware

• FrontPanelExpress.com  Easy to use front panel Designer Software, reasonable pricing

• Hamilton Metalcraft http://hmetal.com - 

• Hammond Manufacturing   https://www.hammfg.com    LOTS of Boxes!

 

• Electronics distributors – many now have DIY and tutorial sections

• Mouser         https://www.mouser.com

• Digikey          https://www.digikey.com