Up for sale is an exceptionally rare matched pair (2 Pcs) of vintage NOS OSRAM KT101 beam power valves, complete in their original British government / military issue boxes. Manufactured in England, these iconic valves feature distinctive black-coated glass envelopes for optimal thermal dissipation and shielding, rugged metal bases, and pristine classic stencil markings. The KT101 is among the premier vintage British output valves highly coveted by audio historians, vintage amp collectors, and high-end audio enthusiasts for its remarkable linearity, depth, and smooth dynamic range.

Both valves have been thoroughly tested and closely matched on a professional AVO Type 160 valve testing machine. Anode current and mutual conductance measurements alongside percentage performance ratings relative to factory specs are detailed in the table below.

Direct Equivalent: 6L6 series tubes (including 6L6GC, 6L6WGB, 5881, and KT66 is a higher-power variant but shares similar construction