DIY projects:

HTPCs - Audio-oriented PCs projects
DACs - Open source Digital (to) Analog Converters
AMPs - Interesting DIY Amp projects
Calbles - Information around cables
Mics - DIY projects to buind measurement mics
Guides - Cool guides/HOWTOs on the net


Softwares - Useful tools for audiophiles
Audio - Free audio stuff for tests (and not only)
Pimp your sound card! - How to get more bass under a heavy headphone load


T-Forum - TClass, the HiFi revolution - Il sito indipendente degli audiocostruttori

SRC Comparisons - Graphic results site for 96Khz > 44.1Khz software resamplers

Passive Crossover Networks - Extremely cool audio tutorial from industrial trainers

Guide to computer audio (PDF) by dCS


Gorini S.r.l. - Local aluminium-heatspreaders manufacturer