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NOS Tubes - Ecstasy or Agony

I have been running tube amps for many years and have built a number of SETs and other tube amps, kit's mostly.  My main power tubes have been 2A3's and 300bs and I have used mostly new manufacture tubes including JJ's and EML 300b's (great tube btw).  I did use NOS driver tubes and headphone amp tubes.  Never really had a problem.

I just transitioned to a Don Sach's 6sn7 based preamp and McCormack SS power amp.  The preamp is very nice and sounds great with Shugang tubes. Of course, I wanted to try some NOS tubes, went online and did my research.  Now the DS2 is a great preamp, the drawback is it uses 4 6sn7s and so I need to get pairs.  Would  have love to get my hands on the Dehavilland, uses one tube!

First Pair - I ordered some Sylvania's from TC Tubes. Advertised as 50's vintage, ,when I received  them they were marked 60's. Hmmm.  So I tried them and they sounded pretty darn good except after a couple hours one of them developed a high pitched hum, like a florescent bulb. So I sent them back.  

Second Pair - ordered from Brent Jesse - has a good rep online and a really informative website.  Received them and one was dead on arrival, they were also clearly of different construction. So they are going back.

Next will try Andy at Vintage Tubes Services, he also has a solid  reputation so hopefully I can get something that works.

I am curious what experiences others have had. Maybe its COVID, or are these dealers just unreliable, or is just 6sn7's?  Really thought I could just buy some NOS tubes and experiment, I can't even get two to work.

I don't really want to disparage these dealers but I do think all the claims of testing are maybe overblown.
drewh1

Showing 1 response by jbhiller

jbhiller's avatar
jbhiller
1,445 posts
 
I feel as though there are very few hard and fast rules when it comes to tubes.  I think it is always a gamble and there are ways to reduce your risk of a not so great outcome. 

I've experienced: 

  • Used preamp tubes lasting forever with no noise or microphonic.  
  • Used preamp tubes lasting 500 - 1000 and fading out fast.
  • New preamp tubes outperforming some great NOS offerings, even those sold by great dealers with great reputations for quality. 
  • Inexpensive reissue preamp tubes performing much quieter than expensive NOS.  Laugh if you want, but Electro Harmonix 6922s, 12AT7s and others are very quiet and lovely sounding.  
  • Used preamp tubes sounding like heaven in a vacuum. 
  • New reissue preamp tubes falling down at 1000-2000 hours.  Unacceptable, but common. 
  • New power or preamp tubes actually sounding their best earliest in their life--despite all of the notions that hundreds of hours of break in make things sound better. 
  • A reissue or NOS sounding not so great in one circuit but ok or great in another. 

The comments above about not knowing how long any given tube will last are spot on.  We never know. 
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