2. amps-preamps
  3. 1185461401

Do tubes "burn in"?

My preamp (octal tubes; cathode-follower outputs) came with two NOS RCA 12SN7GT tubes and I really like the sound I get. Just for grins I picked up a slightly used pair of GE 12SX7GT (U) JAN tubes (Canada) to try. Straight off they were more prolific in the bass and more golden in the mids and highs. I enjoyed these attributes. But the more I listened, the more I noticed the vocals were pushed further forward and the clarity was missing in the mids (vocals, saxophone) when compared to the 12SN7's. I disliked these attributes. The 12SN7's seem to be more evenly balanced throughout. My questions are: Do tubes "burn in" and improve with use? And, can the negative (for me) attributes I described for the 12SX7's improve with burn in (better clarity, less emphasized vocals)?
rockadanny
davemitchell
253 posts
 
Just probably something with the metal getting heated and or some kinda substance burning off the plates and emiting a stronger more consistent current = sound.

That is definately plausable Undertow. It could also be that there is some dielectric interaction especially near the base of the tube. I do also agree that whatever burn-in the tube itself might go through is sonically very minor.
undertow
1,033 posts
 
Caig pro gold is an excellent conditioner to use if the metal is cleaned already on the pins, it gives positive solid / liquid contact... buy it in the Nail polish bottle like this and application is very clean and easy vs. Spraying aerosols all over your tube.. see link
undertow
1,033 posts
 
Forgot link...

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=341-228

Caig pro gold is an excellent conditioner to use if the metal is cleaned already on the pins, it gives positive solid / liquid contact... buy it in the Nail polish bottle like this and application is very clean and easy vs. Spraying aerosols all over your tube.. see link
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