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Do vacuum tube test values reflect sound quality?

I recently ordered a pair of output tubes to try in my LTA MicroZOTL preamp. Two Sylvania 6SN7WGT tubes, Gold Brand. I’ve had good luck with Sylvania 12sn7gt bad boy tubes, so I thought I’d give them a try.

After I bought them, I saw a similar pair for more money that had slightly higher test values. Does that mean they might sound better or that they just have more life left? What properties do you look for in tubes?

Below are the values of the tubes that I bought.

 

Tubes are matched for dynamic gain and structure, testing at 3000-2750 and 3000-2750 where pass/fail is 1625 micromho. They have the same structure inside and out, having matching date codes of "922", the 22nd week of 1959

sls883
larryi
4,184 posts
 

There are instances where someone gets tubes for well below market price, so it is entirely possible for you to have real Telefunkens.  If they are not new in box, the price could be substantially lower than the price I mentioned.  The good news is that these tubes have a very long life, so even old tubes can be good for a loong time.

if you see the Telefunken diamond embossed in the glass on the bottom of the tube, that is a good sign; only the most sophisticated fakes have that embossed pattern.  
 

tksteingraber's avatar
tksteingraber
663 posts
 

@lewm +1

sls883 OP
673 posts
 

@larryi You made me curious, so I pulled one.  There is a diamond on the glass bottom. 

invalid
1,266 posts
 

@lewm  one section of a dual triode could be used for the gain stage and the other section could be used as a cathode follower in a single ended preamp. So both sections still being used.

oddiofyl's avatar
oddiofyl
4,049 posts
 

I use my tester to rule out shorted and weak tubes. Also I prefer balanced triodes as close as possible.   Other than that it’s a crap shoot.   
 

 

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