Here are links to sites which have helped me

https://electro-dan.co.uk/ – great reference for all sorts of audio projects, has helped me massively with chipamps such as the TDA7377 and TDA7396

https://sound-au.com/ – amazing site, full of knowledge and advice. PCBs are for sale and I have used these, they are great and it is a site well worth supporting

https://jlcpcb.com/ – where i buy all my custom PCBs

http://www.pavouk.org/ – excellent reference for DAC information

https://www.veneersonline.co.uk/ – Where i buy my wood veneers for speaker projects. Great quality and quick delivery