12ax7 ecc83 cv4004 5751 e83cc ecc803 6057 6681 7025 7058 7729 b759 m8137 +. mc1 f7h1 code, carefully curated classic audiophile tubes. full mutual conductance gm micromhos % test + life test (longetivity indicator) + gas / leak / short / sound checks.
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(TWICE TESTED;. 2nd)TUBES ARE NOT USABLE UNLESS AUDIO TESTED WITH NO HUM and NON-MICROPHONIC USING MODIFIE D DYNACO PAS 3 & TUBE OTL. TUBE1) 50/50 & 5.1/5.3 ma.
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I'll give you testing photos and the exact tube before sending them out. There are several pairs available. What you see is what you get.
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One of the highest ranked preamp/audio tubes ever made, '50s black plate cbs hytron were limited runs and quite collectible. cbs hytron ~ a premium vacuum tube manufacturer, known for long life low noise legendary playback, only made until 1961.
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Equivalent ECC83, 12AX7. Condition: NOS tubes. Date: V. 1976. I send parcels within 24 hours. Made in Czechoslovakia Roznov.
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6057 - ECC83 - 12AX7 - CV4004 - E83CC. Brimar / 6057. NOS BRIMAR. This is a VERY RARE item, British made during the 1960s or earlier. It features a single O-getter, Yellow-T (yellow shield) markings, and black boxy anode plates.
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The high power 5751 are premium 12ax7 ecc83 w/ slightly less gain, introduced in 1949, as military spec and industrial grade. popular alternative to tungsol / hp command / cbs hytron / general electric, rare 1957 production, authentic rca triangle △ base.
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The high power 5751 are premium 12ax7 ecc83 w/ slightly less gain, introduced in 1949, as military spec + industrial grade. originally designed for aviation, the costly 5751 design is more rugged + less prone to microphonics, w/ higher power 175ma.
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