EL37 Mullard 1950's - 1960's (some branded Philips or Philips Miniwatt)
Best EL37 listed at

(EL37 Mullard is a 25 watt audio output power pentode.  Other similar substitutions are 6L6GC, 5881, KT66, 5932)
(Check with your equipment manufacturer before substituting a EL37 for a 6L6GC or KT66)
(EL37 plate and screen voltage should not exceed 400 VDC)
(Vfil=6.3 @ 1.4A)

EL37 Mullard "BROWN BASE" 1950's - 1960's (brown base EL37 have same great sound as black base EL37) TO BUY EL37

EL37 Mullard "BLACK BASE" and "BLACK PLATE" 1955-1957 TO BUY EL37

EL37 Mullard "BLACK BASE" and "BLACK PLATE" 1957 - 1960 - CARR MERCURY 2003 - Fisher 80-AZ TO BUY EL37

EL37 Mullard "BLACK BASE" and "GRAY PLATE" late 1950's - 1960's TO BUY EL37

EL37 MULLARD ENGLAND (The EL37 are sonically between a EL34 Mullard and GE 6L6GC; strong and punchy with good richness and complexity in the midrange, probably the best 6L6) - Dared VP-20 amps Customer Comments: ----------------- "Just wanted to follow on our conversation yesterday on the Mullard EL37's you sold me. ALL IS WELL AND ALL IS GREAT!!! I found the match in a '64 Deluxe Reverb that I thought sounded great with NOS 5881's, but let me tell you....the EL37's are a different thing...WOW!....THE TONE IS AMAZING! Also and FYI if any of your customers run into the bias issue I did in a Twin Reverb and other bias potted Fenders (lack of ample current). Change the resistor that runs across the bias pot to a higher (or Lower) resistance (mine: 15 ohm to 22 ohm). Thanks from a satisfied customer."

Click here to download pdf file for EL37 Mullard
EL37 MAX RATINGS PENTODE CONNECTED: ---------------------------------- Vplate = 400VDC Vscreen = 400VDC Pout plate max = 25 watts Pout screen max = 6 watts Iplate max = 200ma OPERATIMNG CONDITIONS: --------------------- (2) EL37 in PUSH-PULL CONFIGURATION (FIXED BIAS) Vplate = 400V Vscreen = 400V Iplate = 50ma Iscreen = 6ma Vgrid = -36V Rplate-plate= 3250 ohms Pout = 69 watts (2) EL37 in TRIODE CONFIGURATION (SELF BIAS) Vplate = 400V Iplate = 70ma Iscreen = 6ma Vgrid = -36V Rplate-plate= 4000 ohms Pout = 20.6 watts