Tube chart · Guitar amp
Tubes for Fender Bassman (5F6-A)
Era: 1958–1960 (5F6-A tweed)Power: 45 W
The 5F6-A Tweed Bassman is the spiritual parent of the Marshall JTM45 — Jim Marshall copied this circuit nearly note-for-note in 1962 before shifting to EL34 output. The 12AY7 in V1 is the secret of the tweed-clean sound: lower gain than 12AX7, more headroom, completely different break-up curve.
Complete tube line-up
Every socket in the Bassman (5F6-A), with stock tubes, direct-swap alternatives, and rolling notes. Tube names link to dedicated specification pages.
Important: bias before you swap
Power tube swaps almost always require rebiasing — running a new quartet of 5881 cold or hot will shorten tube life dramatically and can damage the output transformer. See the biasing guide and the troubleshooting guide before rolling tubes.