Specs are community starting points — verify against your amp's manual. (Tube amps: set this to match your impedance selector.)
Tube
Solid State
Cabinets
—
cabinet load
Add a cabinet to calculate
Wiring diagram
What does this wiring mean?
Power distribution
Valid speaker hookups for this amp
Tube amp rule: Never go below the rated output impedance — it stresses the output transformer.
Going higher (e.g. 16Ω cab on an 8Ω output) is safer but affects tone and power transfer.
Exact match is ideal.