Metroamp Forums – Forums populated by do-it-yourself Marshall enthusiasts.
Plexi Palace – The authoritative forums on vintage Marshalls.
Gearslutz – The authoritative Pro Audio forum, featuring world reknown engineers posting regularly.
3DAudio Inc – The old yellow board, devoted to Pro Audio and boutique gear.
Studio Design – Great resource for building or enhancing your own recording studio.
TheGearPage – All about guitar gear.
JTM45 Yahoo Group – Devoted to the coveted JTM45 Marshall head.
18watt Forums – Devoted to the coveted 18 watt Marshall head.