What is the 6J7 vacuum tube?

The 6J7 is a pentode vacuum tube designed for preamp applications. Octal preamp pentode..

What is a 6J7 substitute or equivalent?

Direct equivalents to the 6J7 include None. These share the same pinout and operating envelope, so they can usually be swapped without circuit changes — though batch-to-batch variations between manufacturers (NOS vs current production) may shift the sonic character noticeably.

What are the key specifications of the 6J7?

Transconductance gm ≈ 1.225 mA/V, plate resistance rp ≈ 1500.0 kΩ, max plate voltage 300 V, max plate dissipation 0.75 W, heater 6.3 V / 0.3 A.

Is the 6J7 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 6J7 as Common availability. NOS (new-old-stock) examples from RCA, Mullard, Tung-Sol, GE, Sylvania and Telefunken trade among collectors; modern production where it exists comes mostly from JJ Electronic, Electro-Harmonix, Tung-Sol (New Sensor), Genalex, and a handful of small-batch makers.

What does the 6J7 sound like?

Octal preamp pentode.. Sonic character also depends heavily on the circuit operating point, the surrounding tubes in the stage, and the output transformer when present — use the interactive loadline calculator on this page to explore the trade-offs.