Tubes test NOS. A tube was considered acceptable/new/ passed standards if it tested between the specified minimum and maximum on a tube data sheet or the minimum value specified on the tester (tv7 is minimum is 65%).
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12ax7 ecc83 cv4004 5751 e83cc ecc803 6057 6681 7025 7058. the high power 5751 are premium 12ax7 ecc83 w/ slightly less gain, introduced in 1949, as military spec and industrial grade. originally designed for aviation, the costly triple mica design is rugged + less prone to microphonics, w/ higher power at 175ma.
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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. the top sonic echelon! sought after audiophile crown jewels, revered by enthusiasts for their rich open sound reproduction.
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They were made in Germany in the 1960s. The tubes are super rare, hard to find and in mint condition. The tubes are carefully tested on my tube tester Avo CT160 as in the photos. The tubes may have different letterings and testing values.
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Triple Mica. Made in Germany. Very tightly balanced triodes! ____ ______. Tested in my preamplifier to make sure working as intended with no issues at all. Possibly unused!
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Triple Mica. Matched Pair. Very tightly matched Pair! Made in Germany. ____ ______. Tested in my preamplifier to make sure working as intended with no issues at all. Label is partially erased from handling.
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The tubes are super rare, hard to find and in mint condition. The tubes are carefully tested on my tube tester TV-7 at 49-50 and 48-49/32 min good.
eBay
The high power 5751 are premium 12ax7 ecc83 w/ slightly less gain, introduced in 1949, as military spec and industrial grade. originally designed for aviation, the costly triple mica design is rugged + less prone to microphonics, w/ higher power at 175ma.
eBay