30W Beam Tetrode
A very sought after audio pentode, used in similar applications to the 6L6 and EL34. Both High Fidelity, like the Quad II or Leak 12.1 , and instrument amplifiers were produced by many makers. The classic example is the Marshall Model 1961 JTM45 combo as used by Eric Clapton with John Mayall's Bluesbreakers on the 'Beano' album.
