12AU7 / ECC82 TELEFUNKEN NOS Amplitrex Tested - Ribbed Plates - ◊ Diamond Bottom - Made in West Germany

12AU7 ECC82 NOS TELEFUNKEN Amplitrex Tested Ribbed Plates Tubes ◊ Diamond Bottom Made in W. Germany

Description:

This 12AU7 / ECC82 TELEFUNKEN NOS , produced in West Germany , is an original example identifiable by the characteristic ◊ Diamond Bottom on the case back, an unmistakable mark of Telefunken production.

The ribbed plate construction is known for its high mechanical stability and extremely coherent electrical behavior, qualities that have made these versions particularly popular in the hi-fi and professional fields.

This is an authentic NOS (New Old Stock) tube, never used, tested in our laboratory with the Amplitrex AT-1000 to verify its output, linearity and correct operation.

A select specimen, designed for high-level audio applications where precision and reliability are crucial.

Rated Low Noise & Microphonics , it is also suitable for sensitive circuit positions.

Sound Characteristics

Bass: Compact, controlled, and well-structured. The low range is linear and precise, with excellent articulation and a sense of solidity.

Mids: Neutral, clear, and highly defined. Vocals are clean and well-focused, while instruments maintain harmonic balance and transparency.

Highs: Extended and finely detailed. The top end is airy yet disciplined, with great clarity and no harshness.

Dynamics: Quick and controlled. Transient response is prompt, with precise microdynamics and consistently consistent behavior.

Soundstage: Stable and well-organized soundstage, with good depth and orderly separation of sound planes.

🎧 Use in Hi-Fi Amplifiers

Ideal for:

• medium-high and high quality line preamplifiers
• driver stages and phase inverters
• integrated amplifiers and power amplifiers that require stability and silence

Particularly suitable for systems oriented towards precision, neutrality and definition.

🎸 Use in Music Applications

Also appreciated in:

• instrument amplifiers
• studio equipment
• sensitive entry positions

It offers defined response, harmonious balance and reliable behavior over time.

🎯 Note for audiophiles and technicians

• Original Telefunken production – Made in W. Germany
• Case Back ◊ Genuine Diamond Bottom
• Ribbed Plates
• NOS – New Old Stock
• Tested on Amplitrex AT-1000

A model that expresses the precision and solidity of the Telefunken school, with a neutral, coherent and technically reliable sound character, in full Vacuum Tubes Treasures style.

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Test Results:

Valve tested on AMPLITREX AT-1000 Tube Tester:

• Test Conditions: Va = 250V, Vg = -8.5V
• Average 100%: Gm = 2200 ; Ia = 10.5 mA
• Test Result: VERY STRONG

Valve:

• Section 1: Gm = 2200 ; Ia = 9.2 mA
• Section 2: Gm = 2200 ; Ia = 9.4 mA

Additional Tests Performed:

• Microphonics: Low. Tested and approved for use in hi-fi, including phono stages and guitar amplifiers. Also suitable for V1.
• Output Quality: Excellent – ​​Very strong and stable output, no fluctuations.
  
• Short circuits and GAS: Absent.

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Conditions:

• Condition: NOS - New Old Stock - Tested and in perfect working order. Comes in our custom box for optimal protection.
• Functionality: Fully functional.
• Cosmetic condition: Good – Lettering partially eroded, but still legible. Valve body in good condition. See photos for details.

Manufacturing Code:

• hh → December 1956

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