NOS tubes are a great way to improve the sound your system produces. If you are going to purchase quality NOS tubes there are things to look for to make sure you are getting what you expect.
This post is going to focus on the Mullard M8162 that is rebranded by Beard. You’ll discover over the course of this blog my favorite flavor of tube is the Mullard, so of course I like these! I’ve got a set of them currently in my main tube amp that I just can’t get enough of. So let’s dive right in!
The M8162 will be called different names: CV4024, ECC81, but must most commonly the 12AT7 (WA). Many NOS tubes were made by one manufacturer and then branded/re-branded by another. Besides the silk screening on the outside of the glass everything else is 100% Mullard.

Model Code
You’ll also notice the code on the glass 654. This signifies it is an M8162 or CV4024.

halo getter
They have a halo getter that some will swear changes the sound. I’m not in that group. I think the getter does its job, but really only helps to confirm the era it was made when identifying tubes.

cross seams
These also have the Euro style cross seams on top of the tubes.

Ladder Plates
If you look at the picture you can see the double ribbed ladder plate that these tubes are known for having.

Plant/Year Code
For me, the numbers R3A2 on the tubes are the most important. They signify what plant they were made in and the year of production. In this case Mullard, Mitcham Plant year 1983.
The plant/year makes a big difference when selecting tubes. A different year means different runs of tubes. Quality of work and quality of materials can vary and can change the sound of a tube even if it is from the same plant and a different year. Something I really like about Mullard tubes is a pretty consistent quality and tone from the Mitcham plant tubes. If you’re interested in a bit of history on the plant here is a great video to give some insight and a side by side comparison of a Mullard label and BEARD branded Mullard.
My personal take on these tubes falls in line with how most people feel about Mullards. They have a nice thick midrange, and the highs are extended but not harsh. I run horns in my system so harsh highs are something that can happen easily, but not with this tube. They are very non-fatiguing even at high volumes. Of course, the lows are solid, accurate and typical of Mullards of this quality. Click on the picture below and grab a pair from VTUBEAUDIO!
Just remember tubes were relabeled/rebranded by plenty of companies. Know what you are getting before you buy. Make sure it’s from a reputable source and that the tubes are tested before you buy. VTubeAudio has been my go to for tubes. Here is a picture of my BEARD M8162 in my system.