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Questions about tubes and gear that glows. FAQ

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RE: Now I Need Rectifier Help!

Posted by Palustris on December 29, 2016 at 13:10:59:
Only Western Electric made a 274B.

All the Chinese tubes with the 274B label are variations on the 5U4. While they might make your amplifier sound fine, they are not really 274B tubes. If you check these Chinese 274B tube's specifications against the actual 274B specifications in the Western Electric Tube Data book, you will find many differences. If you check the specs. for the Psvane WE274B 1:1 Replica for which there is the ridiculous assertion that "Even the production humidity and temperature are followed 100% to ensure the complete replication" you will find that while they may have the humidity and temperature correct, the actual specifications of the tube differ (heater current, max plate voltage and current, length and width of the glass envelope).

The Chinese sell a lot of 274B labeled tubes that may sound good and some may even sound something like a 274B, just don't think you are buying a real 274B or that silk screening a tube with 274B turns the 5U4 into something magical.