1 17

MULLARD

12AX7 / ECC83 NOS MULLARD – Blackburn 1959 – Matched Pair – Short Gray Plates – Halo Getter – Same Data Code – AMPLITREX Tested

12AX7 / ECC83 NOS MULLARD – Blackburn 1959 – Matched Pair – Short Gray Plates – Halo Getter – Same Data Code – AMPLITREX Tested

2.661,00 DKK
2.661,00 DKK
Sale Sold out
Taxes included. Shipping calculated at checkout.

12AX7 / ECC83 NOS MULLARD – Blackburn 1959 – Short Gray Plates – Halo Getter – Matched Pair – Same Data Code I61 B9K – AMPLITREX Tested

Description:

This matched pair of NOS Mullard 12AX7/ECC83s , produced in the historic Blackburn (Great Britain) factory in 1959 , represents one of the most appreciated configurations of the British Mullard production.

The valves have the classic internal structure:

  • Short Gray Plates
  • Halo Getter
  • Mullard Blackburn production
  • identical data code: I61 B9K

The I61 code identifies the famous Mullard structure for ECC83 with short plates , while B9K confirms the Blackburn 1959 production, one of the most sought-after periods by enthusiasts.

The specimens are NOS (New Old Stock) and are presented in showcase aesthetic condition , with perfectly preserved silkscreen prints and internal construction.

Both tubes have been thoroughly tested in our laboratory with the AMPLITREX AT-1000 , verifying emission, stability and operating behavior. They also proved to be Low Noise & Microphonics , qualities that make them suitable even for the V1 position in the most sensitive circuits.

Sound Characteristics

Mullard Blackburn ECC83s are renowned for their natural musicality and warm, engaging character, which has made these tubes a favorite among audiophiles and musicians.

Bass: Deep and well-controlled. The low end is full and authoritative, with an excellent balance between body and precision.

Mids: The strong point of the Mullard tradition. Vocals sound rich, three-dimensional, and very natural, while acoustic instruments and harmonics emerge with great presence.

Highs: Sweet and refined. The highs are well-extended yet elegant, with a fine texture that encourages long, relaxed listening.

Dynamics: Very fluid. Dynamic variations are reproduced naturally and seamlessly, always maintaining great musicality.

Soundstage: Wide and stable soundstage, with nice depth and very credible instrument separation.

🎧 Use in Hi-Fi Amplifiers

Mullard Blackburn ECC83s are among the most sought after tubes for:

  • tube preamplifiers
  • phono stages
  • hi-fi amplifier drivers
  • high-end vintage audio equipment

Thanks to the low noise and reduced microphonics , this pair is perfectly suited even for the most critical positions of the circuit , including V1 .

🎸 Use in Music Applications

In the world of musical instrument amplifiers, the 1950s Mullard ECC83s are considered a benchmark.

They offer:

  • rich and musical mediums
  • very expressive dynamic response
  • excellent timbre definition

Features that contribute to a warm, articulate and very musical sound.

🎯 Note for audiophiles and technicians

  • Mullard–Blackburn (Great Britain)
  • Year of production: 1959
  • Structure I61 – Short Gray Plates
  • Halo Getter
  • Identical Data Code: I61 B9K
  • Matched Pair
  • NOS – Showcase condition
  • Low Noise & Microphonics – also suitable for V1
  • AMPLITREX AT-1000 Tested

An authentic 1959 Mullard Blackburn pair , with identical production numbers , built in one of the most iconic factories in vacuum tube history. A combination of build quality, musicality, and historic appeal that continues to make these ECC83s among the most sought-after by vintage audio enthusiasts.

Test Results:

Valve tested on AMPLITREX AT-1000 Tube Tester:

  • Test Conditions: Va = 250V ; Vg = -2V
  • Average 100%: Gm = 1600 ; Ia = 1.2 mA
  • Test Result: STRONG

Valve #1:

  • Section 1: Gm = 1500 ; Ia = 0.9 mA
  • Section 2: Gm = 1800 ; Ia = 1.2 mA

Valve #2:

  • Section 1: Gm = 1500 ; Ia = 0.9 mA
  • Section 2: Gm = 1800 ; Ia = 1.4 mA
Additional Tests Performed:
  • Microphonics: Low. Tested and approved for use in hi-fi, including phono stages and guitar amplifiers. Also suitable for V1.
  • Noise: Low and well-controlled. Silent operation in hi-fi and music amplifiers in the intended positions.
  • 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.
  • Cosmetic condition: Excellent – ​​Excellently preserved lettering, minimal signs of wear. See photos for details.

Manufacturing Code:

  • I61 B9K→ I6x indicates an ECC83 with the sequential progression of x, where the increment of x indicates the production changes - B9K B → Mullard, Blackburn - 8 (over three figures) → 1959 - K → November

Find out why our valves are different →

Terms of Sale & Safety

Sales Terms & Product Safety

Each vacuum tube is carefully selected, tested, and verified in our laboratory before shipment. Where stated in the listing, test results, matching data, and declared characteristics refer to measurements performed using the specified test equipment and operating conditions.

Sound descriptions are provided for guidance only and reflect the characteristics generally associated with that particular tube type. Personal sound preferences, tube rolling, or perceived differences between audio systems do not constitute a product defect.

Before installation, please verify the tube’s electrical and mechanical compatibility with your equipment and follow the manufacturer’s instructions.

New production and NOS tubes are shipped with a tamper-evident security seal and internal technical documentation to ensure traceability of the product’s condition at the time of shipment.

Product Safety (GPSR)

Vacuum tubes are electronic components intended exclusively for use in compatible equipment and must be installed in accordance with the equipment manufacturer’s instructions.

Due to their historical or vintage nature, certain technical specifications may be based on original datasheets or equivalent technical documentation when documentation from the specific manufacturer is unavailable.

Use only with suitable equipment. Keep out of reach of children.

Shipping & Returns

Shipping & Returns

We ship worldwide using carefully selected express carriers and protective packaging specifically designed for vacuum tubes.

If you change your mind, you may exercise your right of withdrawal within 14 days of delivery, where applicable under the relevant consumer protection laws. The product must be returned complete with its original packaging and accessories, in the same commercial condition in which it was received. Return shipping costs are the responsibility of the customer.

Every returned item undergoes a technical inspection. Installation, use, tube rolling, or any other handling may reduce the product’s commercial value and may affect the refund amount, in accordance with applicable law.

If you believe the product has a lack of conformity, our laboratory will carry out the necessary inspections and apply the remedies provided by the applicable consumer protection legislation.

For further details, Customers are invited to consult the “Terms and Conditions” and “Refund Policy” sections of our website, or to contact us before placing an order.

Vacuum Tubes Treasures
www.vtt.store | www.vacuumtubestreasures.com
📧 info@vacuumtubestreasures.com

View full details

  • ATTENTION PLEASE

    Please understand that the writing on the glass of vintage valves has become very delicate over the years and comes off easily. You must handle them with extreme care to avoid this. Wear and damage to the writing on the valves reduces their market value and causes damage. Please exercise extreme caution.

  • ATTENTION PLEASE

    We wish to inform you that any attempts to manipulate shipping destination information in order to obtain lower shipping rates may be considered fraudulent acts. Please provide accurate information and contact us if you have any concerns. We reserve the right to review and, if necessary, cancel orders that we deem to be in violation of our conditions. Thank you for your understanding and cooperation.