AUDIO VALVES: EL37 CV586 CV1947 PP60 6L6G 5881 OUTPUT PENTODE
The EL37 audio output valve is of pentode configuration and is Mullard’s answer to the mighty KT66 beam tetrode. These meaty beasts could deliver up to 70 Watts at 2.5% distortion when used in push-pull.
Developed from the earlier EL31 and rerated to have higher anode dissipation, the EL37 in characterised by having a massive mutual conductance when compared against it’s contemporaries. Indeed, 11.0 mA/V is almost twice the value of that shown by the KT66 or the 6L6.
Introduced in 1946, the EL37 was superseded by the introduction of the EL34 some 8 years later, praised for their scarcity, their exceptional sound and ease of driving they are keenly sought for audio amplifier and guitar amplifier applications today, key examples of which include: -
Dr. Z Route 66
Marshall Bluesbreaker JTM45 MKIV 1966
Marshall Bluesbreaker reissue 1964
Marshall JTM45
Metro Amp (George Metropoulos)
Metropolis JTM-45 2009
Pure Sixty-Four The "64" Head
QUAD II
Soultone 1986ps
THD Bivalve
Victoria Regal 2