2 old stock matsu/mullard 12ax7 ecc83 preamp audio tubes, matched pair carefully curated direct japan import + twice tested 
the british supplied expertise and tooling via 'transfer of technology' resulted in several critical audiophile advantages:
same anodes, micas, electrode geometry, glass envelope, spot welding, grid wire spacing and cathode processing chemistry!
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take your listening experience to a higher level of 3-dimensional engaging detail and immersive harmonic imaging
transform sound reproduction across multiple genres w/ more realism, rich bass and holographic textured resolve
translucent highs and warm tone euphony, live-concert style delineation between instruments vocals and percussion
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full conductance test 94/92~94/92 % mutual gm (65%)+ important life test pass! = longetivity indicator
our special gm output test applies real world 225vdc voltages w/ filtered dc, plus an impeccable gas test and leak/short check
gm scores relate to current-transfer ability, especially important for push pull preamps
we pride ourselves on a proprietary complimentary value-added refurb screening deox process
give several sessions or up to 100+ hours w/ your specific amps voltage to settle in (break-in is important)
ships well packed worldwide ~ several pairs in stock! singles or quads upon request + free postage!
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authentic vintage hifidelity audiophile / preamp / mic tube curation by caliacoustics
see our offical site for reserve/request options + new part number list below
including limited special editions + rare true-nos sealed box + pinched waist
also high-resolution headphones + premium vocal stage and studio mics
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6dj8 7dj8 6922 7308 / ecc88 pcc88 e88cc e188cc cca
12ax7 12at7 12au7 12bh7 / ecc83 ecc82 ecc81 e82cc
6bq5 6au6 6267 6ca7 6ca4 6aq5 / 6v6 6l6 6sl7 6sn7 5y3 5u4 5ar4
5814 5751 5965 6189 6201 7062 7189 / cv2492 cv4004 cv455 cv4085
el34 el84 ef86 ef94 ez81 ecc85 e180cc gz34