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MULLARD

12AX7 / ECC83 MULLARD Blackburn Tested Pair Short Grey Plates Halo Getter Low Noise & Mic

12AX7 / ECC83 MULLARD Blackburn Tested Pair Short Grey Plates Halo Getter Low Noise & Mic

€199,90 EUR
€199,90 EUR
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12AX7 / ECC83 Mullard Blackburn – Selected Pair – Same 3-Character Code I61 B1C – Short Gray Plates – Halo Getter – Made in Great Britain

AMPLITREX Tested – Low Noise & Microphonics – Early Blackburn Production – Selected Vintage Pair

Description

Selected pair of 12AX7 / ECC83 Mullard Blackburn, Made in Great Britain production, belonging to the early British Mullard Blackburn productions and chosen for constructive consistency, same production origin, and overall operational quality.

Both tubes bear the same etched code I61 B1C, an element of great interest for aesthetic, constructive, and historical consistency. The code B1C refers to a very early Blackburn production from 1951, a period now particularly sought after by enthusiasts of vintage British ECC83s.

The construction features Short Gray Plates and a top Halo Getter, with architecture typical of the British Mullard school, appreciated for musicality, tonal balance, and naturalness of sound presentation.

The pair is offered as a Selected Vintage Pair, not as a precision matched pair: the two tubes share the same factory, same code, and homogeneous internal structure, albeit with not perfectly identical electrical values, which is consistent with authentic used vintage Mullard Blackburns over seventy years old.

The tubes have been tested using an Amplitrex AT-1000 Tube Tester with particular attention to quietness, microphonics, and operational stability. Both showed regular behavior, Low Noise & Microphonics, absence of GAS, and absence of short circuits.

From an aesthetic point of view, they are in good condition and consistent with their age, with signs of time and screen print wear, while still maintaining an authentic and very charming appearance. See photos for details.

Sonically, they offer the typical character of early Mullard Blackburns: warm yet balanced reproduction, rich and material mids, sweet and well-integrated highs, natural and controlled bass. The presentation is fluid, organic, and very musical, ideal for those seeking the classic British Mullard tone.

Suitable for hi-fi preamplifiers, line stages, compatible phono stages, driver stages, integrated amplifiers, instrument amplifiers, and circuits compatible with 12AX7 / ECC83. The Low Noise & Microphonics selection also makes them interesting for sensitive positions, including compatible phono and V1 applications.

A Mullard Blackburn I61 B1C pair with strong historical and sonic appeal, genuinely selected by Vacuum Tubes Treasures for those seeking authentic early production British ECC83s, consistent, quiet, and musically refined.

Test Results:

Tube tested on AMPLITREX AT-1000 Tube Tester:

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

Tube #1: STRONG

  • Section 1: Gm = 1200 ; Ia = 0.8 mA
  • Section 2: Gm = 1400 ; Ia = 0.9 mA

Tube #2: VERY STRONG

  • Section 1: Gm = 1300 ; Ia = 0.9 mA
  • Section 2: Gm = 1700 ; Ia = 1.3 mA
Additional Tests Performed:

  • Microphonics: Low. Tested and suitable for hi-fi use, including phono stages and guitar amplifiers. Also suitable for V1.
  • Noise: Low and well controlled. Quiet operation in hi-fi and musical amplifiers in intended positions.
  • Balance: The sections show not perfectly coincident values, an aspect consistent with an authentic selected vintage pair. The pair remains fully interesting for hi-fi and musical use in compatible circuits.
  • Emission Quality: Strong – Strong and regular emission, suitable for any application.
  • Short Circuits and GAS: Absent.

Condition:

  • Condition: Vintage Tubes - Tested and fully functional. Supplied in our custom box for optimal protection. 
  • Functionality: Perfectly operational.
  • Aesthetic Condition: Good and consistent with age. Signs of time, slight screen print wear, and normal vintage patina are present. See photos for details.

Manufacturing Code: 

  • I61 B1C → I6x indicates an ECC83 with the sequential progression of x, where the increment of x indicates production changes - B1C B → Mullard, Blackburn - 1 (out of three digits) → 1951 - C → March

Discover why our tubes 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
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  • 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.