The Tung‑Sol 7027A is your best bet for original-spec power tubes in vintage high-voltage amps. Ships well, boasts a strong build and tone, and comes in matched sets for a few dozen pounds/euros. Just be sure to bias correctly, and you’ll get solid performance and reliability.

• The Tung‑Sol 7027A is a modern reissue of a vintage beam‑power tetrode originally used in high‑voltage amplifiers (like Ampeg B‑series & V‑series) as well as McIntosh® tube gear.
• A 35 W beam tetrode, roughly similar in performance to 6L6GC but built to handle higher voltages and current, named with extra internal pins to withstand elevated plate/screen stress
• 7027, 7027A. Not pin-compatible with 6L6GC—requires an amp specifically wired for a 7027 pinout.