New Old Stock – NOS tubes

Today, we introduce the fascination of NOS tubes, provide tips and advice on their usage, and also reveal how to identify and avoid counterfeits!

We musicians are quite a unique bunch

Well-worn guitars, yellowed Tweed amps, and, ideally, plenty of “mojo” in effects pedals, cables, and the like – all of these bring a blissful smile to our faces. Who wants to play brand-new equipment, anyway? What starts with instruments and amplifiers extends to components of all kinds. Those that go by the name “NOS” (“New Old Stock”) parts spark enthusiasm among collectors, tinkerers, and even investors. The old stock of potentiometers, capacitors, and tubes can be sold for substantial sums. However, what’s popular is quickly counterfeited, and more than a few musicians have fallen for seemingly attractive offers.

Tweed Two-Twelve-65, 5F8A Style

Buying NOS tubes – what is it exactly?

The term NOS, which stands for New Old Stock, is used to describe components and, in this context, electron tubes that are offered for sale and originate from the old stock of former manufacturers. In essence, they are the items that were not released onto the market during the heyday of tube technology. The reason there is still a significant supply of New Old Stock electron tubes is due to the production capacity of the earlier manufacturers and the rapid transition to transistors that displaced electron valves – the tube technology was almost overnight declared “old-fashioned.” This is good news for those who still value the sound and warmth of vintage originals today.

5751 RCA NOS/USA double mica, black plate

New Old Stock vs. Modern Tubes – A Matter of (Good) Taste

First and foremost, from a purely technical standpoint, there are hardly any reasons to prefer an electron tube from old stock over a modern, newly manufactured variant. But from a purely technical standpoint, there’s also no reason to prefer a 1959 Les Paul Standard over a 2021 model – yet, most guitarists would probably still do so. The reason for wanting to buy old NOS tubes lies, as so often in our musician’s world, in subjective values.

1978 Fernandes FLG-70 VX


The sound that old tube amplifiers, in their original configuration, deliver at the amplifier is the reason why we, as Tube Amp Doctor, even exist. Few modern amps provide the same warm and natural sound as a well-played, old Tweed or Blackface amp. The technical standard for guitar amplifiers in the 1950s and 1960s was the electron tube, and during this time, everything was done to optimize production and the associated sound. It’s no wonder that old NOS tubes are attributed with incredible musicality and sonic strength – just like the accompanying guitar amplifier. As always, the perception of tone and music is subjective, even with NOS tubes, but you can’t deny that they have that certain something!

Blackface 45 Reverb AB763 Style Amp-Kit


Many amplifier models, whether they are Fender instrument amplifiers or hi-fi equipment, were designed during the heyday of tube technology to meet specific requirements and demands – sometimes with innovative and occasionally peculiar components. Especially niche amplifiers like phono preamps or special guitar amplifiers, due to their construction, require tube types that are no longer available or are extremely hard to find today. In such cases, using NOS tubes is the only way to operate these old treasures in accordance with their original design.


While vintage enthusiasts and fans of “old” sounds might reluctantly admit it, when it comes to listening to and enjoying music, feeling plays a significant role. Of course, a well-sounding modern Class D amplifier, connected to high-quality speakers and used with high-resolution digital media, provides excellent audio quality. However, the feeling that comes with old technology, original components, and decades of history remains unmatched and is reason enough for many collectors and tinkerers to incorporate NOS tvalves into their devices.

6550A GE NOS (USA)

Is buying NOS tubes recommended for everyone? Risks in using/buying NOS electron valves

NOS tubes are truly niche products, serving a very select market. In addition to hobbyists and musicians, you’ll also find collectors and speculators who want to earn some extra euros with old technology. However, dealing with and using old tube technology is not always without risks. Here, we’ve taken a closer look at two areas where caution should be exercised.

Harmful Substances and Safety

Technical processes and products are continually evolving, improving, and being adapted and processed based on the latest knowledge. This, of course, applies to amplifier tubes as well. While the basic technological principles have remained the same, the materials used have varied over time and have often been replaced or improved. However, when you opt for NOS tubes, you’re essentially going back in time, bypassing important safety knowledge about handling these tubes. It’s not uncommon for tube types from the early days of radio to have been processed with harmful substances (mercury vapor, asbestos, etc.). These substances are no longer allowed to be used today for very good reasons. Particularly when buying from private sellers without expertise, extreme caution is required. Far too often, potentially harmful components are offered, and inexperienced buyers celebrate them as bargains.

To avoid the risk of harmful substances, it is advisable to purchase NOS tubes from experienced, reputable dealers – here, customers can be confident that the highest modern standards are followed, and the necessary expertise is applied! We’re happy to assist you with this – just give us a call or contact the TubeAmpDoctor online shop.

6AN8A / 8489 USA / NOS

Counterfeiting and Fraud

Old tube types from rare series are often traded for high sums – a global phenomenon in the age of the internet. Components, particularly those originating from Soviet production, are frequently offered. However, as with all online transactions, caution should be exercised: All too often, apparent bargains turn out to be bold counterfeits by some fraudsters who have chosen gullible music enthusiasts as their new target. Relabeled cheap tubes are sold as alleged wartime new stock, and sometimes even markings and engravings on the tube bodies themselves are altered and adjusted. If you’re not 100% sure, you should not trust private sellers and shady vendors. If you truly want old, original technology, there’s no way around consulting an expert or a specialist dealer for new items.

NOS Tubes – Conclusion

NOS tubes allow you to fully enjoy the unparalleled feeling of old, well-running tube technology. During the heyday of tube technology, some very high-quality, great-sounding components were produced, which are hard to replicate even today. However, the fascination with NOS tubes is spreading, and some of the risks associated with old components or counterfeit offers are often underestimated. If you want to experience the charm of old NOS tubes without exposing yourself to the risk of counterfeits or harmful substances, you should turn to a specialist dealer. TAD frequently offers larger batches of NOS components – guaranteed to be original and selected according to our highest standards!

ECC81 Telefunken / RFT (NOS)
Image source:

1978 Fernandes FLG-70 VX electric guitar: by yoppy from Kawasaki, Kanagawa, Japan – 石 Fernandes FLG-70 VX, CC BY 2.0,