Which replacement tubes and upgrade tubes for Air Tight amplifiers are available from BTB?

We supply suitable replacement tubes and upgrade tubes for many Air Tight units. These include, for example, the ATM-1 2024 with 1 x 12AT7 / ECC81, 2 x 6CG7 / 6FQ7 and 4 x EL34, the ATM-2Plus with 2 x 12AX7, 4 x 6CG7 / 6FQ7 and 4 x KT88 / 6550, as well as ATM-300 / ATM-300R models with 300B and 5U4GB as rectifier tube. Other Air Tight amplifiers such as ATM-1S, ATM-2211 or ATM-3211 are also covered. Many common types for Air Tight units are available from us in selected quality and, on request, matched.