Best 5814A listed at:

5814 / 5814A / 5814WA (12AU7 Substitute) (the 5814A is equivalent to a 12AU7WA, it is ruggedized and redesigned; the filament current raised to 175ma per section versus 150ma per section for a 12AU7. 5814A is computer rated, 5814WA is ruggedized)
(click on links below to check stock) 5814 / 5814A GE 1950's - 1970's 5814A GE JAN 1960's - 1970's 5814A Marconi Canada 5814A Raytheon 5184A RCA Black Plates 5184A Siemens Germany 5184A Sylvania
5814 / 5814A / 5814WA GE 1953 - 1970's (5814A is a direct substitute and a ruggedized 12AU7, also see 5963 and 6189) (The best 5814A are Siemens Germany, RCA black plates and JG or 5 Star GE) - Woo Audio WA4 headphone amp - TRON Seven phono (can only use 5814WA only) - Bottlehead Crack TO BUY 5814A GE
5814 and 5814A 1950's: --------------------- 1960's - 1970's: ---------------
5814A GE JAN 1960's - 1980's (green printing) TO BUY 5814A GE JAN

5814A=12AU7 Marconi Canada 1950's TO BUY 5814A Marconi
3 low noise pairs $85/pair) 5814A Marconi Canada NOS gray plates - triple mica - large "U" getter halo - original boxes - mid-1950's - best value
5814A=12AU7 Raytheon 1955 - Bottlehead Foreplay - CJ PV12 - Jadis amp TO BUY 5814A Raytheon

5814A=12AU7 RCA 1950 - 1970's (recommended, great sounding sub for 12AU7, low noise, sweet sound, great bass) 1950's -1960 triple mica: ------------------------ 1960's - 1970's: smooth sound --------------- PAIRS: ----- TO BUY 5814A RCA
SONIC COMMENTS: -------------- "Dear Brendan, I originally called you about getting a replacement pair of Siemens 5814, being used in a Sonic Frontier amplifier, with Western Electric 300B. You had stated that the Siemens would give the most accurate reproduction of the 300B. But, you went on to further recommend that if I wanted a little more warmth and a little more richness in the upper end, that I would try a pair of RCA-Circa 1950s 5814. It was a wonderful recommendation, it makes the amp sound more lively, definitely a richer tone and gives a nicer roundness that we didn't have with the Siemens's. So once again, thank you for you help. Sincerely, Peter Lee"
5814A=12AU7 Siemens West Germany (very transparent 12AU7 sub, lots of inner detail, airy highs, this tube is very neutral, reference quality) (recommended for DACS and linestages) (also see E82CC Siemens and 12AU7 Siemens) - Unison Research Unico-P 2005 - Einstein preamp - Head-Direct EF1 Hybrid Headphone Amp 2008 TO BUY 5814A Siemens
E82CC=5814A Siemens 1980: best value
5814A=12AU7 Sylvania / Philips USA - Acoustic Masterpiece AM201 TO BUY 5814A Sylvania