Sylvania 12AX7's

Type

Sylvania 12AX7 – Vintage NOS USA-Made Preamp Tubes

Four Types. One Legendary Sound.

While RCA, Mullard, and Telefunken get most of the glory, those in the know recognize Sylvania 12AX7s as one of the best-kept secrets in the NOS tube world. These American-made preamp tubes deliver top-tier performance at a far more accessible price, making them ideal for players and audiophiles looking to upgrade without breaking the bank.

From pristine clean tones to rich warmth and gritty breakup, Sylvania 12AX7s offer exceptional tonal variety. That’s because they weren’t just made one way—Sylvania manufactured four distinct versions over nearly three decades, each with its own sonic personality:

Long Grey Plates (1960s–early '70s)

The most well-known Sylvania variant. These tubes are warm, spacious, and remarkably clean—offering a touch of added headroom compared to typical long plates. Perfect for blackface Fenders, pedal platforms, and HiFi setups that crave shimmer without harshness.

Long Black Plates (late '40s–mid '50s)

The originals. These bring a gritty, vintage edge with lower headroom and a thick, saturated tone. A favorite among guitarists chasing that classic pre-CBS sound. For HiFi, they require strong mutual conductance to shine—we only stock fully tested, noise-free examples.

Short Black Plates (1955–1958)

Warm, punchy, and significantly quieter than long plates, these refined performers are ideal for both HiFi and guitar. Expect deep bass response and excellent noise rejection, all with the signature Sylvania musicality.

Short Grey Plates (1958–1962)

Built for military-grade durability and noise control. Often found with JAN labels, these are workhorses with slightly less warmth but unbeatable reliability. We recommend these for phase inverter duties or for anyone needing quiet, balanced power on a budget.

Read about the four types of Sylvania 12AX7 here!

Need help deciding what tubes are best for you?

Use our plate cheat sheet and vacuum tube buyers guide to determine which tubes are best for you. Likewise, you are welcome to reach out to us directly at Support@FuzzAudio.com or by using our chat located on our shop page if you have further questions.

NOS vs. ANOS vs. Test NOS

These designations are strictly used to describe the cosmetic condition of our tubes. All tubes we sell test identically, come with 100% life and are guaranteed to work in your device!

If you are picky about owning an original box or wanting a specific logo please reach out to us before purchasing.

  1. NOS (New Old Stock) Tubes- are 100% brand new vintage tubes in mint cosmetic condition with show zero signs of use. You should expect a legible logo and clean straight pins. An original box is likely but not guaranteed. 
  1. ANOS Tubes- otherwise known as “almost new old stock” tubes are basically new, but may show slight signs of use in cosmetic condition, such as a missing logo or slightly bent pins. An original box is possible but unlikely. 
  1. Test NOS Tubes- are used but still operating to specification with 100% life. These tubes are equal in function to NOS valves, yet they cost considerably less because they have cosmetic blemishes. If you plan to disappear your tubes into the back of an amplifier or do not care what the tubes look like, then this is cost effective choice. Blemishes and cosmetic imperfections do not affect tone…

Logos: Vintage tubes have a wide variety of logos printed on them. It is not uncommon to see a Mullard made tube with an RCA or GE logo, or a GE made tube with a Mullard logo. Your tube may come with a logo such are Heath Kit, Baldwin, Fisher, Hammond, Magnavox, Fender, Gibson, Silvertone, etc. but the true manufacturer of that tube will be correct to your order. If you are looking for a specific logo please reach out before purchase.

Our Standards:

  • All tubes are tested for microphonics and are guaranteed to work in sensitive audio applications
  • All tubes sold are guaranteed to have strong (to spec) NOS test scores with 100% life
  • All tubes are tested on a calibrated Hickok 539C, Maxi-Matcher, E-Tracer or other industry standard tube analyzers
  • Tubes are guaranteed for one year and can be returned within 30 days
  • Preamp tubes matched by gain and mutual conductance (Gm)
  • Power tubes matched by mA and Gm

Don’t forget to email Support@fuzzaudio.com or reach out to us via chat if you need help picking out valves for your device.

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