5 links
Acme Sound Bass Speaker Cabinets
acmebass.com
Andy Lewis' flat-response extended-range "Low B" line of 3-way bass speakers. Direct sales.
Bass Gear Review Page
bgra.net
Huge archive of bass-related user reviews including preamps, power amps, amp heads, speaker cabinets, combo amps, and effects.
Fuchs Audio Technology
fuchsaudiotechnology.com
Design and hand-build tube amplifiers; includes model speficications and dealer network. Also offer a custom-build service.
Harmony Central Amp Database
harmony-central.com
Large database of guitar and bass amplifier and speaker user reviews.
valveamps.com
valveamps.com
Collector and restorer of old valve guitar amplifiers describes his collection.