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Tube rolling newbie- how to choose NOS tubes

I’ve purchased a xDuoo TA-30 dac/amp for my first tube rolling experience. From online reviews, I plan to tube roll in a Matched Pair of Mullard 12AU7.

Looking online, there are new reissued Mullard 12AU7, matching NOS tubes at various price points, years, features (like long plates?), and used tubes like on eBay.. This is confusing, how do I choose? Should the tubes be tested? Who should I purchase from?

 

kennyc
czarivey
5,650 posts
 

@facten Credible vendors do almost same but from different "position".

Didn't you know that there are so many positions that you can get "poked". Read the ENTIRE Kamasutra to gen an idea how :) 

tomic601's avatar
tomic601
12,733 posts
 

complete waste of time and money to buy nos or other tubes without significant run in time for your new component…. burn in, listen critically, discern where you want to go… (  IF you don’t know where you are going, ANY road ( and $$$$ ) will get you there…..

lowrider57's avatar
lowrider57
5,391 posts
 

Be warned...new production Mullards are not the real Mullards. A major manufacturer of tubes in Russia bought the name. They have no semblance to the sonics of NOS Mullards which were manufactured in UK or by their parent company Philips, Holland.

Start with Brent Jessee, knowledgeable and very accessible. Andy at Vintage Tube Services sells primo tubes, but last I checked, there was a three month wait for fulfillment.

ieales's avatar
ieales
1,201 posts
 

@kennyc 

 B E F O R E  you do anything, find out what the tubes do in the circuit:

  • do they provide gain or just buffer for cachet
  • are they used in a balanced configuration or single ended
  • if balanced configuration, are they actively balanced or fixed

NOS tubes can be gassy and take a while to come to life... or may never 😞

See 5963Match.png (605×341) (ielogical.com) and 5963MatchDelta.png (605×341) (ielogical.com).

This is four NOS 5963 [similar to 12AU7] used as a driver stage in two amps. There are 24 possible combinations of these tubes. Each combination sounds different.

And read ieLogical Rolling

 

macg19
659 posts
 

complete waste of time and money to buy nos or other tubes without significant run in time for your new component…. burn in, listen critically, discern where you want to go

I disagree with this. Many manufacturers of tube-based gear ship their products with the best sounding, current production tubes that are readily available and don't increase cost of materials too much. Their expectation is that you will roll tubes - pretty obvious, why else would you buy a tube DAC.

All you need to do is leave your DAC on for a few days, identify what you don't like or want more of (in my case it was a high-frequency harshness/sibilance), and try out some NOS tubes. 

+1 @lowrider57 I got my most recent tubes from Brent in less than a week, and that was only because he is really busy.

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