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?



For start learn your dac/amp with factory supplied tubes.

Most likely reissued Mullard are rebranded ones like the ones you already have.

For true NOS tubes or ones in good shape better trust a good vendor, who can do the testing and supply what you are looking for.

Buying blind from ebay without knowing what to search before having established a good knowledge about this particular tube or tubes may prove very expensive.

Here is some previous discussions on Agon about this tube.

Good hunting.


Google Brent Jessee or Vintage Tube Services. Both are respected tube sellers who will help you find the tubes you want. They probably will not be cheap , but who knows, you may get lucky. Buying tubes from these guys is not cheap but it is cheaper than learning about NOS tubes by trial and error.  Brent will usually get the tubes to you faster than Andy (VTS).

As petg60 has recommended, get familiar with the sound of your DAC/amp with the stock tubes in it and have an idea of how you would like to change that sound with your new tubes before calling the tube sellers..

+1 for Brent Jesse his advice is top notch and his return policy is more than fair. Basically you pay for shipping and get to try something else within 30 days no risk.

But definitely let the stock tubes break in if the DAC is new and get used to them as others have said.

Many of the reissues are mediocre, some are good for the specific application (JJ comes to mind).  

You will learn a lot and get pricing from his web site here:

Emailing him is best, explain what you have and what you are looking for. Don't get stuck on Mullards though (nothing against them, I have a pair in my DAC from Brent that I love but they were $450 a pair) but there are other great NOS options that might be obtained for less.

Not sure what the rest of your system is but there is a point of diminishing return to consider.


+ whatever on Brent Jessee.

@kennyc  here is the link to his website, if you click on the specific tube type you are interested in a page will come up with impressions on different brands and equivalent tube models


I haven't used Vintage Tube Services , but as noted by another member he gets good reviews. Another option is TubeDepot

+1 brent jesse

he had me break a set in (simply leave unit on for 60 hrs, no music playing needed), then let me return them.

I tried a different pair, loved them, and they were half the price, full refund for the difference in price.

+6 on Brent Jesse.

But first start with reading user experiences here. Go through a ton of them so that you have a fairly good idea on the "flavor" for each brand of NOS.

Then reach out to Brent Jesse and don't ask him about the NOS tubes you shortlisted. Just tell him YOUR preference - what you like your music to sound like or what you would not like. TBH, in my mind (reading experiences here), I would have thought about Amperex Bugle Boys. Based on my needs he advised  on Mazda Grey plates 1960s tubes. All I can say is I am super thrilled with these tubes. One thing about NOS is - they are so good that I did not feel the need to break them in. Of course, they will get better with time. But starting with hour 1 itself was a revelation.

The thing I do not like about NOS is - they are like drugs - you can check them out, but you cannot get off 🤨

"To void risk of being skimmed, buy current tubes."

Buy from credible vendors and you don't have to worry about it

Another vote for Brent Jesse. Having said that, different tubes have different tonal qualities.  So when you call BJ, let them know just what you’re looking for.

All the best.

@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 :) 

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…..

Be 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.


 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) ( and 5963MatchDelta.png (605×341) (

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


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.

Talking the push from above comment i can add that most tube rollers forget, that current manufacturers create their gear with modern tubes for sound and characteristics in mind. Also they do not assume or expect that everybody will do tube rolling. They go with what is available at the time of production. On the other hand we are not certain that a NOS tube would bring vast improvement, many times it can be the opposite. This means proceed with caution, money spent elsewhere in the system can sometimes yield better results.

But you would not know if not trying and that is a part of the game.

But you would not know if not trying and that is a part of the game.

... of fleecing the uneducated.

Thanks all for your advice, I'm learning a lot.  This is my first experience with tubes so I'm in experimental mode to understand the sonic differences between tubes. I'll also be using my DAP as a SS desktop dac/amp to sonically compare. 

As a tube newbie myself, I’m more than happy to pay up a bit for a reputable tube expert with a reasonable return policy to point me in the right direction and who will likely save me considerable time and $$$ from buying either the wrong or bad tubes.  I’d just make sure to have a price point in mind going in and communicate that upfront because this can get silly expensive, especially if you don’t know yet what your doing or what tubes are really worth.  Great advice here that I’ll definitely use myself. 

I would spend some time reading different forums as some have suggested. Just search for the type of tube you’re looking for in the application you’re using it. It’s amazing what you can learn from others especially their mistakes. I’m still a novice so I like learning from others. NOS tubes are not always what they’re cracked up go be. I’m not saying to avoid them but it’s a cost/benefit situation. Is that $150.00 NOS tube worth three times as much over good current production tubes? Does your system warrant the expenditure? You’re in the same realm as cables here. My best advice is read, read, read.

A known tube seller with a well supported supply to the UK took on a usually seen approach from a sales person when questioning the era of a NOS Tube from a later production era, vs a earlier production era.

I was pretty much told I was being mis-informed and with them being an authority, they should know that their Later NOS Production Tube is on Parity or even better that the earlier Production.

That story probably lasts until earlier production models are discovered and offered for sale at a much increased price, and a inquiry is made about such a Valve.

I don't think the parity word will be used in a description, unless it is used to compare to another Brands Tube from a similar era, and commanding s similar price.

I found the Tubes over a period of Time as a early 60's Production, and when Tube Rolling compared them to 70's Production, which the latter were quite inferior in the presentation and no where near as attractive when in use.

Treading Carefully and being very selective about where one take their influences will help steer toward a successful NOS experience.

My time now is spent looking into the reports of New Production that fairs very favourably to NOS Tubes. There are some very positive findings to date.

These latest versions of tubes being discovered, will for myself, most likely be the purchases made for the future Tube exchanges, as finding very good, close to Manufacturer Spec', Matched in Measurement Tubes, from a 40-50 year old era is almost like going on a search for finding Rocking Horse Poo. 

Thanks all, I’ll look up Brent Jesse.

I have to be careful as I have an additive personality and may get caught in the accumulating tubes rabbit hole.