Offered here is an exceptional, pristine quad lot of 4 vintage TELEFUNKEN (TFK) EF11 black metal envelope pentode valves, beautifully preserved in clean white boxes. Made in Germany, these iconic vintage audio-grade components feature the legendary Telefunken Diamond logo stamped cleanly onto their robust black metal envelopes.

As clearly visible in  the envelopes carry the authentic white production/date stamp markings: 106, 104, 103, and 117. This historical batch has been comprehensively analyzed on the  digital tester, and the performance parameters verified in confirm excellent health and stability across all four units relative to standard factory specifications.