12AU7 / ECC82 MULLARD Blackburn 1958 - Long Gray Plates - Goalpost Getter - Strong & Stable - Amplitrex Tested

12AU7 / ECC82 MULLARD Blackburn 1958 - Long Gray Plates - Goalpost Getter - Strong & Stable - Amplitrex Tested - MADE IN GT. BRITAIN

Description:

This Mullard 12AU7 / ECC82 , produced in the historic Blackburn factory (Great Britain) in 1958 , belongs to the first and most appreciated production phase of the British ECC82. Original Mullard model, Blackburn (Great Britain) production, manufacturing code B8F , dating back to 1958.

The construction with long gray plates and goalpost getter identifies a version of great technical and historical interest, typical of the Mullards of the late '50s, characterized by mechanical solidity and an authoritative sound setting.

The sample was tested on an Amplitrex AT-1000 . The internal sections show different values ​​from each other (about ~20%), while maintaining stable output and coherent behavior during the test . It is therefore not a balanced tube, but an electrically healthy and operational sample.

Sound Characteristics

Bass: Full and well-structured. The low range is rounded and solid, with good support and natural depth.

Mids: Warm, textured, and rich in harmonics. Vocals are dense and realistic, with that typical Mullard signature that emphasizes musicality and naturalness.

Highs: Sweet and well-integrated. The top end is extended but never aggressive, with a soft and refined texture.

Dynamics: Smooth and progressive. Transient response is natural, with a coherent and unrelenting musical delivery.

Soundstage: Wide and well-organized soundstage, with good depth and stable image focus.

🎧 Use in Hi-Fi Amplifiers

Ideal for:

• line stages
• preamplifiers
• positions where perfect symmetry between the sections is not required

Particularly suitable for systems that enhance body, naturalness and a harmonious imprint.

🎸 Use in Music Applications

Also very valid in:

• instrument amplifiers
• circuits where musicality and harmonic richness are priorities

It offers a warm and engaging, typically British delivery.

🎯 Note for audiophiles and technicians

• Original production Mullard – Blackburn 1958
• Long Gray Plates – Goalpost Getter
• Tested on Amplitrex AT-1000
• Stable emission
• Internal sections with a difference of ~20% (not balanced)
• Consistent electrical behavior during testing

An example of great historical charm, an authentic expression of Mullard production from the late 1950s, designed for those seeking musicality and British character in a vintage 12AU7, in true Vacuum Tubes Treasures style.

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: STRONG / VERY STRONG

Valve:

• Section 1: Gm = 1600 ; Ia = 7.6 mA
• Section 2: Gm = 2000 ; Ia = 10.2 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 – ​​Strong and stable output, no fluctuations.
  
• Short circuits and GAS: Absent.

Conditions:

• Condition: Vintage tubes - Tested and in perfect working order. Shipped in our custom box for optimal protection.
• Balance: The sections are not perfectly aligned. This tube is intended for use in hi-fi on non-critical stages (input or driver) and in guitar amplifiers. It is not suitable as a phase inverter or in applications requiring a precise balance between the sections.
• Functionality: Fully functional.
• Aesthetic condition: Very good – Clearly legible writing with minor signs of wear, no obvious defects. See photos for details.

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