the breath of life! top sonic echelon '50s cbs metallurgy is warm, like a live concert in holographic realism, and transparency

often described by listeners as a highly musical performer, incredibly detailed, smooth singer vocals, all w/ articulate playback
great dynamics, intimate low-register, exquisite definition, and sweet imaging, all w/ an immersive reveal of complex passages
the colorful harmonics, expansive sound stage, and dimensional bloom, all contribute to the collectible sonic lore of cbs usa

+ special gold grids which minimize heat, reduce cathode-current contamination, and provide more detail + stage resolution
++ the legendary black carbide plate coating radiates heat, reduces plate temps, and enhances tonal + breakup characteristics
+++ best version w/ dgetter euphony! old school cbs are rising-value collectibles, and only made up till 1961 in salem ma usa


tweak, tune-up + transform your harmonics, measured feedback, tonal articulation, clarity, and system definition
elevate your sound across more genres and musicality types, w/ richer bass depth, textured harmonics, and acoustics

take your listening experience to a higher level of immersive engagement from percussion or brass, all w/ vinyl style warmth


vintage rectifiers are a great way to affect headroom and power, based on the voltage supplied

the 6x4 has a history going back to the 1940s, and replaces the EZ90 6z31 cv493 u78 v2m70 u707

w/ premium versions = 6063 6x4w and cv4005, and different max-rating versions: 6202 6BX4 and 6X4WA

these will be similar (w/ different connections so re-wire or adapter) to 6z4 chinese and 6Ц4П russian variety

+ similar to the different-base classics (rewire / adapter): 6x5 6x5gt ez40a or the cv572 ez35 / 5993 we351a 5852

6X4/w EZ90 U78 V2M70 U707 6AV4 WTT100 CV493 6063 6X4W CV4005 QA2407 6Z31 6202 6BX4 6X4WA 


       6C4P-EP      6X4

pin 1   a1           a1

pin 2   nc           nc

pin 3   f            f

pin 4   f            f

pin 5   k            nc

pin 6   nc           a2

pin 7   a2           k


give several sessions (150+ hours) w/ your amps specific voltage to fully break-in
2 sold, 1 left in stock (75 % gm ) ships well packed worldwide! express/priority available by request

~ authentic vintage hifidelity audiophile preamp / mic / power / rectifier tube curation ~
see our official site + new arrivals + reserve/request special pricing + limited editions
+ sealed-box true-nos rarities + pinched waist collectibles + ultra high res headphones