Electro-Harmonix tubes are among the highest quality. Engineered, designed, and manufactured to exacting standards for musicality and overall warmth, you can trust an Electro-Harmonix tube to deliver premium tone.
eBay
This tube comes from the estate of an audiophile technician who meticulously curated a collection of over 1000 tested and excellent tubes! I will be listing the tubes individually and testing for good or better on a Hickok 799 or Sencore MU140. All writing and measurements on boxes were made by the previous owner and although I believe them to be accurate, some variation may occur. See the last photo for an idea of the span of the collection. This photo is for context only. This listing is only for the tube represented in the title. Feel free to ask questions! I have been a recording engineer for 20+ years and will do my best to answer your inquiries :)
eBay
Here we have for sale is a very rare 12AX7 ECC83 tube. This is a special quality ANOS tested Mullard B339 ECC83 tube based off the M8137 CV4004 box plate design. Platinum BALANCED triodes. My personal favorite 12AX7 variant as the Mullard M8137 CV4004 has the best bass qualities of any 12ax7 ecc83 tube in my personal opinion.
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Brand New in great condition Mullard Master Series
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The plate current is a bit low, but the transconductance very high. GM (mA/V) - 1.6. ia (mA) - 1.2. Data Book Specification. GM (mA/V) - 1.8. ia (mA) - 0.8.
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6057 CV4004 ECC83 12AX7 Valve Tube. Mullard, British Made. Used, Supplied in White Box.
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However, "B" date code indicates this pair is made by Mullard in England. Short Plate. Strong pair! Made in England. Made in Blackburn England. Tested in my preamplifier to make sure working as intended with no issues at all.
eBay
Electro-Harmonix tubes are among the highest quality. Engineered, designed, and manufactured to exacting standards for musicality and overall warmth, you can trust an Electro-Harmonix tube to deliver premium tone.
eBay