Sovtek 6550WE Power Tubes, Platinum Matched SextetThe Sovtek 6550WD and 6550WE were designed to be the finest 6550's ever produced. Thicker plates, improved heat dissipation, higher transconductance, and increased linearity are just some of the inherent aspects of the new Sovtek super 6550's. The resulting performance advantages include 5% higher output power, increased reliability, greater headroom, and superior tone. The 6550WE features a metal ringed base for increased power handling capabilities.