revered by audiophiles, vintage electronic industry nis tubes were the last to be based on telefunken and philips technology
this smooth plate old production is sought after for warm realistic vocal reproduction, and an upper-mid register showcase
resonant thick metallurgy halo getter, legendary playback w/ a rich resolve, transparent imaging, and subtle treble roundoff
these premium 12ax7 ecc83 capture the purest holographic spatial tone, lowest noise, and live-concert vinyl style intimacy
6 piece collectible set, authentic ei Ω etch code w/ siemens + aeg branding, includes plain tube boxes

full mutual gm conductance test: 75/78 ~  84/85 ~ 85/105 ~ 101/100 ~ 110/120 ~ 120/105 % gm (65 % good) 
+ useful life test pass! a key longetivity indicator, plus an impeccable gas test / leak / short check
our special mutual gm dynamic output test applies real world 225vdc circuit voltages w/ filtered dc
we also pride ourselves on a proprietary complimentary value-added refurb screening deox process, one of a kind qc
give several sessions or up to 100+ hours w/ your specific amps voltage to settle in (break-in is important)
ships well packed worldwide w/ free economy postage

~ authentic vintage hifidelity audio curation by caliacoustics ~
see our official web site for reserve/request options, true-nos sealed box rarities and limited run special editions