Sovtek EL34WXT NIB (1990s) Perfectly Matched QUADS

NOS/NIB Sovtek EL34WXT (1990s). Black Logo. Black Base. Perfectly Matching QUADS. Original Sovtek Match Rating: 7.

These came from a large collection of tubes that was sealed in 2014. I obtained the collection in 2021. This listing is for one quad of EL34WXTs. Verified Matched & NOS with a Hickok Model 752 tube tester. Test value stickers added to base:

• Leakage Test: Pass
• Gas Test: Pass
• Gm (Hickock 752): 7200, 7250, 7300 & 7300 (See more info below)
• Life: 100%
• NOS/NEW

Note: Tube tester readings are based on Hickok 752 specification at bias point 23. The range scale is 10X (so 10 times the measured value on the Micromhos scale). These tubes test as NEW and well above the standard bogey of 6500. The Sovtek-branded EL34 tubes no longer exist, however they are closest to modern production Electro-Harmonix (EL34-EH) or Mullard (EL34). These tubes would have been the original tubes for Marshall JCM900 series amplifiers.

(Google AI)

• Since they have a black base and no date codes, your EL34WXTs are likely from the early-to-mid 1990s.In the world of Russian tube production, the black base was the standard for the original "Reflector" factory tooling before New Sensor (Sovtek's parent company) transitioned many of their premium lines to the brown micanol bases in the 2000s.
• The "WXT" (without the plus) was often the version found in Marshall and  Mesa/Boogie amps during that era.
• The standard "New" bogey for an EL34 on a Hickok is 6,000 to 6,500 $\mu$mhos.
• Matching: For a 100-watt amp, try to group them into pairs that are within 500 $\mu$mhos of each other. If all four are within that range, you have a solid matched quartet.

 These tubes test NEW (and very strong) with 100% life remaining. They are perfectly matched at 1.3%.