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Calling All Tube Gurus

I know everyone loves to have their tubes come from the same date codes and manufacturers. But just how critical is this?


If you can determine that a tube was made in the same plant, has the same construction and date codes, how critical is it if the tube was made by Siemens and rebranded as an Amperex? Or let’s say the tubes has the same construction but were manufactured within a year or so of each other?


I’ve heard people say that if a manufactures tubes are not up to their standards, THOSE are the tubes they send out to the other manufactures for their branding. Fact or fiction?


Has anyone experimented to see how these variables actually affect their music? I realize everyone has their own tolerance to what is acceptable to them, and that it can also be system dependent, but I am curious to the findings any of you may have.

elrod

Showing 1 response by yesiam_a_pirate

yesiam_a_pirate's avatar
yesiam_a_pirate
235 posts
 

To your date code question: I think it's not really relevant as tubes from the same batch can vary by a LOT.  I read that manufacturers think 5% variance is fine. Try 5% louder in your left channel and me that me 5% is fine. :)

I once replaced a pair of Sovtek 6550s that were damaged by red plating. I bought NOS Sovteks that were matched. Popped them in and viola! Louder on the left. Another tube- a Sylvania BH7A was causing the red plating. I replaced it with NOS. Soon after the right channel BH7A started acting up.  I realized that the best practices way to have avoided all this wasted time and money was to buy a whole tube set already matched from my manufacturer. "Your first loss is your least loss" 

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