12AT7 / ECC81 SYLVANIA NOS – Black Square Plates Halo Getter – Export Quality Made in USA

12AT7 / ECC81 SYLVANIA NOS – Black Square Plates Halo Getter – Export Quality Made in USA

Description:

This pair of NOS 12AT7 / ECC81 SYLVANIA , Made in USA , belongs to an Export Quality selection , intended for the most demanding markets in terms of construction standards and reliability. The configuration with black square plates and halo getter identifies one of the most appreciated versions of the vintage Sylvania ECC81, renowned for its electrical coherence, stability over time and sonic refinement.
From the very first notes, the whole thing conveys the feeling of a carefully selected, solid, and well-finished component, capable of enhancing quality equipment with an authentically American character.

Sound Characteristics

Bass
Compact and well-controlled. The low end is tidy and precise, with a dry response that supports the rhythm without weighing down the musical message.

Medium
Clear, present, and very natural. Voices emerge with good intelligibility and body, while acoustic and jazz instruments benefit from a clean and coherent harmonic texture.

High
Open and bright, yet well-integrated. The highs are elegant, free of harshness, with a sense of air and detail that makes listening smooth and enjoyable.

Dynamics
Prompt and smooth. The response is lively yet composed, with balanced microdynamics that keep the music alive without being aggressive.

Soundstage
Stable and well-focused. The soundstage is clear, with credible separation of levels and a realistic presentation.

🎧 Use in Hi-Fi Stereo Amplifiers
Ideal for:

• preamplifiers and line stages,
• drivers and medium gain stages,
• vintage and modern hi-fi systems that require transparency and reliability.

The Sylvania sound signature is best expressed on jazz, vocal, classical and fine listening.

🎸 Use in Music Amplifiers
Excellent for:

• guitar amplifiers and instruments,
• V2/V3 positions and driver stages,
• circuits that require signal definition and control.

They offer a clean, musical and very balanced sound.

🎯 Note for audiophiles and technicians

• American production selected for export
• high-level internal construction and great stability
• balanced, bright and refined timbre
  

An ideal choice for those who want not only a NOS tube , but a reliable and musically satisfying sound experience , faithful to the spirit of the best Sylvania productions.

Test Results:

Valves tested on AMPLITREX AT-1000 Tube Tester:

• Test Conditions: Va = 250V ; Vg = -2V
• Average 100%: Gm = 5.5 ; Ia = 10 mA
• Test Result: VERY STRONG

Valve 1:

• Section 1: Gm = 5.8, ; Ia = 11.4 mA
• Section 2: Gm = 6.1 ; Ia = 10.8 mA

Valve 2:

• Section 1: Gm = 6.0 ; Ia = 11.6 mA
• Section 2: Gm = 6.2 ; Ia = 12.4 mA

• Microphonics: Low. Tested and approved for use in hi-fi, including phono stages and guitar amplifiers.
• Output Quality: Excellent – Very strong and stable output, no fluctuations.
• Short circuits and GAS: Absent.

Conditions:

• Condition: NOS - New Old Stock - Tested and working - Supplied in our custom box for optimal protection.
  
• Functionality: Fully functional.
  
• Aesthetic conditions: One of the two tubes has completely lost its original silkscreen print on the glass. This is purely cosmetic and common on NOS tubes from this era, especially those with fragile varnishes or those that have been stored for a long time.
  The identification as an original SYLVANIA Made in USA is confirmed without any doubt by the internal structure , materials and construction, perfectly consistent with Sylvania Export Quality production. See photos for details.
  
• Manufacturing Code: Unreadable. Year of manufacture detected by internal structure - Made in the 1960s.

Find out why our valves are different →