Telefunken 6550-TK Black Diamond Series Vacuum Tubes (Matched Set of Four)

This matched set of four Telefunken 6550-TK Black Diamond Series Vacuum Tubes is ideal for use in Leslie cabinets and guitar, bass, and keyboard amplifiers in homes, studios, and live stage applications. For personal enjoyment, live performance, or commercial recording, they grant the essence of a 6L6 with increased gain and enhanced stability. In a slightly larger footprint than a 6L6, each beam pentode (or power tetrode) tube delivers up to 35W of output power and extended longevity.

Ideal for use in Leslie cabinets as well as guitar and bass amplifiers

Design based on the 6L6, but with more gain and enhanced stability

Inspired by the classic 6550, which was developed by Tung-Sol in 1955

Delivers up to 35W at the tube output

Extended longevity means fewer tube changes over the years

Each tube is meticulously measured for all critical parameters of performance including transconductance, gain, noise, and microphonics

Tubes are selected by hand, rigorously tested, subjected to an extended burn-in period for stability, and remeasured before final packing