(!!!!!) (Recommended Pair) ECC33=6SN7GT Mullard UK black plates NOS pan shape getter halo 1950-1955 era (10.2/8.6ma and 9.5/8.6ma) (best sounding ECC33 of all-time)
(!!!!!) (Recommended Pair) ECC33=6SN7GT Mullard UK black plates NOS pan shape getter halo 1950-1955 era (8.6/9.6ma and 8/10ma) (best sounding ECC33 of all-time)
(!!!!!) (Recommended Pair) ECC33=6SN7GT Mullard UK black plates NOS pan shape getter halo 1950-1955 era (9.6/9.8ma and 9.6/10.6ma) (Highest mA and Gm) (best sounding ECC33 of all-time)
(!!!!!) (Recommended Single) M8137=CV4004=12AX7 Mullard branded Philips box plates NOS 1966 (Gm=1500/1400 and 1.0/0.8mA)
(!!!!) (2nd Best Pair) CV4004=12AX7 Mullard NOS 1981 (0.9/0.9ma and 0.9/1.0ma)
(!!!!) (Best Brimar Single) CV4024=12AT7WA Brimar NOS square black plates 1975 (13.4/13.6ma)
(!!!!) (Best CV4003 Quad) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (8.4/9.0, 8.4/9.0, 8.4/8.8, 8.4/8.8mA)
(!!!!) (Best Holland Single) 12AX7A=ECC83 Amperex Globe Logo Holland ribbed plates NOS 1970 (1.4/1.4ma and Gm=1700/1800) 1-2% section balance
(!!!!) (Best Mullard Single) 12AU7A Amperex by Mullard UK NOS ribbed plates 1974 (10.6/11.6ma) (DAC, linestage)
(!!!!) (Best Overall Pair) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (9.6/9.6ma and 9.4/9.8ma) 1% matched (can make a quad with another pair)
(!!!!) (Best Overall Quad) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (8.8/8.8, 8.8/8.8, 8.6/8.8, 8.6/9.0mA)
(!!!!) (Best Overall Single) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (10.8/11.2ma) 1-3% section balance
(!!!!) (Best Overall Single) CV4003=12AU7=6189 Mullard UK NOS 1978 rebranded "6189 RTC" 1981 (13/12.8ma) (Highest mA and Gm)
(!!!!) (Best Overall Single) CV4004=12AX7 Mullard box plates NOS 1971-1972 (Gm=1600/1700) (1.3/1.5ma)
(!!!!) (Best Overall Single) CV4024=12AT7WA Brimar NOS square black plates 1966 (11.2./11.4ma)
(!!!!) (Best Overall Single) ECC81=12AT7 Philips Miniwatt France by La Radiotechnique NOS 1962 (8.8/8.8ma) 1-2% section balance
(!!!!) (Best Overall Single) GZ37 Mullard UK NOS 1966 (52/40 and 52/40) 1% section balance
(!!!!) (Best Pair 1955) CV378=GZ37 Mullard "D" getter NOS 1955 faded printing (56-56/40 and 57-57/40 x 2 tubes)
(!!!!) (Best Pair 1966) CV378=GZ37 Mullard NOS 1966 (51-51/40 x 2 tubes) 1% matched
(!!!!) (Best Pair) 6L6G MULLARD UK NOS 1959 (63.5ma and 64.0ma) 1-3% matched
