Electro Harmonix 6550 - 6550

Electro Harmonix is the top end brand which is owned by the Sovtek corp. Many of these valve designs are new designs based on old classic items.
6550 Electro Harmonix has seen a number of design of improvements which has resulted in a superb sounding 6550.

They use a Tri-alloy plate material for maximum power and dissipation which supplies a better current transfer. The valve has stronger internal bracing with steel rod mica supports which has resulted in very low microphonics.

They have also increased the surface area of the plate and EH claim 42 watts in tetrode operation. They have used a new cathode coating and ruggedized the screen grid to improve performance and reliability. If that was not enough they have used a special high-temperature leaded glass for reliability and vacuum integrity thus making the valve resilient to shock when the valves are thrown around in flight cases.

Sound wise this has is big and aggressive tone the improvements provide a more linear response with extra headroom which will allow bass player s to get the full treble clarity at the top end without any fuzz.