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MULLARD

12AX7 / ECC83 MULLARD Blackburn Short Gray Plates Halo Getter - Same Code I61 B1C - AMPLITREX Tested Pair - Low Noise & Microphonics

12AX7 / ECC83 MULLARD Blackburn Short Gray Plates Halo Getter - Same Code I61 B1C - AMPLITREX Tested Pair - Low Noise & Microphonics

1.525,00 DKK
1.525,00 DKK
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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

This pair of 12AX7 / ECC83 Mullard Blackburn, Made in Great Britain production, represents a vintage selection of particular historical and technical appeal, belonging to early British Mullard Blackburn productions.

Both tubes bear the same engraved code I61 B1C, a very interesting element for manufacturing consistency and production origin. The 3-character date code B1C refers to a very early Blackburn production from 1951, a period highly sought after today by enthusiasts of vintage British ECC83s.

The construction with short gray plates and a top halo getter recalls the classic British Mullard architecture, known for musicality, tonal balance, and natural sound presentation.

This pair is offered as a Selected Vintage Pair and not as a precision matched pair. The two tubes share the same production origin, the same internal structure, and the same manufacturing code, despite presenting electrical values that are not perfectly identical, an aspect absolutely consistent with authentic used vintage Mullard Blackburns over seventy years old.

The tubes have been carefully tested and selected using the AMPLITREX AT-1000 Tube Tester, with particular attention to quietness, microphonics, and operational stability. Both showed regular behavior, low microphonics, and no GAS or short circuits.

Aesthetically, they are in good condition, consistent with their age: there are signs of time, wear of the silk-screening, and an authentically lived-in appearance, but overall they remain very presentable and visually appealing.

Sonic Characteristics

The early Mullard Blackburn ECC83s are renowned for a musical, textured, and natural sound presentation, capable of combining harmonic richness, fluidity, and a particular sense of organic quality.

This pair clearly retains the typical character of the British Mullard school: a credible, warm yet balanced sound, with refined harmonic texture and consistently musical response.

Bass

The bass range is natural, composed, and well-articulated. The bass maintains a good presence without becoming intrusive, contributing to a stable and coherent sound presentation.

Midrange

The midrange represents the true strength of this early Blackburn production. Vocals emerge with naturalness and texture, while acoustic instruments and harmonics retain a rich, fluid, and credible texture.

It possesses that typical vintage British musicality that has made Mullard ECC83s particularly appreciated in both hi-fi and musical contexts.

Treble

The treble range is sweet, refined, and well-integrated. Detail remains present without aggressiveness, with a reproduction that favors long and relaxed listening sessions.

Dynamics

The dynamic response is fluid and progressive, with good readability of musical variations and a consistently composed and natural presentation.

Soundstage

The soundstage appears stable and well-organized, with good instrument separation and credible depth. The reproduction remains musical and coherent, without artificiality.

🎧 Use in Hi-Fi Amplifiers

These Mullard Blackburn ECC83 / 12AX7 are particularly suitable for:

  • hi-fi preamplifiers;
  • line stages;
  • phono stages;
  • driver stages;
  • vintage and modern systems compatible with ECC83 / 12AX7.

The Low Noise & Microphonics selection also makes them suitable for sensitive circuit positions, including phono applications and high-gain configurations.

The tubes have also been verified as suitable for use in the V1 position.

🎸 Use in Musical Amplifiers

In guitar amplifiers and musical applications, this Mullard Blackburn pair can offer a harmonically rich response, expressive mids, and a very natural musical presentation.

British Mullard ECC83s are historically appreciated in vintage and boutique circuits for their ability to maintain musicality, fluidity, and a consistently controlled high range.

Low microphonics and good operational stability also make them suitable for compatible professional uses.

🎯 Note for Audiophiles and Technicians

This pair represents a particularly interesting selection for those who desire authentic Mullard Blackburn ECC83 / 12AX7 with:

  • same engraved production code I61 B1C;
  • very early Blackburn production;
  • short gray plates construction;
  • halo getter;
  • low noise & microphonics selection;
  • typical vintage British Mullard musicality.

This is not a precision matched pair, but a vintage pair selected for production consistency, homogeneous internal structure, and overall operational quality.

A solution with strong historical and sonic appeal, designed for those who wish to integrate the authentic character of the early Mullard Blackburns into their system, while maintaining full technical credibility and professional selection.

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 designated positions.
  • Balance: Sections do not have perfectly coinciding 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.

Conditions:

  • Condition: Vintage Tubes - Tested and fully functional. Supplied in our custom box for optimal protection. 
  • Functionality: Fully operational.
  • Aesthetic Condition: Good and consistent with age. Shows signs of time, light wear of the silk-screening, and normal vintage patina. See photos for details.

Manufacturing Code: 

  • I61 B1C → I6x indicates an ECC83 with sequential progression 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 →

Condizioni di vendita e sicurezza

Anti-Tamper Security Seal Policy:
Each product is sealed to guarantee quality and integrity.
The right of withdrawal is subject to the seal remaining intact, as provided for by the Consumer Code.

Eco-Friendly Packaging:
The tube will be shipped with protective packaging to ensure safety during transport.
We use recycled and recyclable paper for packaging, along with brown ECO-KRAFT adhesive tape, eco-friendly and solvent-free.

Important Notes:
This tube, manufactured according to the standards of its era, is designed to operate in equipment compatible with vintage tubes.
It is recommended to follow standard safety guidelines to avoid malfunctions or damage.

Safety Assurance:
Although not tested according to modern GPSR regulations, this tube was designed to operate safely under the conditions for which it was manufactured.
We recommend using it only with equipment that supports vintage tubes, in order to avoid risks of malfunction or damage.
Technical data note:
In some cases, the technical data provided may be based on datasheets from other manufacturers or on equivalent historical specifications, when a specific official datasheet for the production batch of the listed item is not available.
Electrical characteristics may vary slightly depending on the production batch and manufacturing period, as is typical for thermionic components.

Safety Information:
Warning: Keep out of reach of children.
To be used under adult supervision.
Use the product only with equipment designed for vintage tubes.

Shipping & Returns

Shipping & Returns

Shipping Costs

Shipping costs vary depending on the total amount of the items in the cart and are calculated automatically during the checkout process.
All shipments are fully insured. The courier is automatically selected based on destination, weight, and shipment characteristics.

Shipping Times and Delivery

The indicated delivery times are purely indicative.
Any delays, storage issues, or operational changes made by the carrier (for example during peak periods such as holidays) are not attributable to Vacuum Tubes Treasures.

In such cases, we will nevertheless provide the Customer with all necessary support to open claims or assistance requests with the appointed courier.

International Shipping (Non-EU Countries)

For orders shipped to countries outside the European Union, any customs duties, import taxes, or additional charges are the sole responsibility of the recipient.
Vacuum Tubes Treasures has no control over these costs, which may vary from country to country. Customers are therefore advised to contact their local customs authorities prior to placing an order.

Warranty

All products sold by Vacuum Tubes Treasures are covered by the legal warranty of conformity, in accordance with Italian Legislative Decree No. 206/2005 (Consumer Code) and the Italian Civil Code (Articles 1490 et seq.), under the conditions set out below.

Warranty for Vacuum Tubes

Vacuum tubes, being components subject to wear and of vintage or specialized nature, are covered by a specific warranty of 6 (six) months from the date of delivery.
The warranty covers exclusively proven manufacturing or conformity defects that arise during proper use in accordance with technical specifications.

The warranty does not cover:

  • normal wear and tear,
  • subjective sound preferences,
  • use in incompatible equipment,
  • tampering or improper use.

Right of Withdrawal

Purchases made on the Vacuum Tubes Treasures website are governed by Italian regulations on distance contracts (Legislative Decree No. 206/2005).

Consumers have the right to withdraw from the contract within 14 (fourteen) days from the date of receipt of the goods, without providing any reason.

Conditions for Exercising the Right of Withdrawal

The right of withdrawal may be exercised only if:

  • the product has not been used,
  • the product is returned in its original condition,
  • the tamper-evident security seal is intact and not broken.

📌 Returns are not accepted for reasons related to sound preference, tube rolling, or subjective audio evaluation.
As with a music recording, a vacuum tube cannot be returned simply because its sound does not match personal taste.

Effects of Withdrawal

In the event of a valid withdrawal:

  • all payments received, including standard shipping costs, will be refunded,
  • refunds will be issued within 14 days from receipt of the returned goods,
  • the refund may be withheld until the goods have been received and inspected.

Refunds will be made using the same payment method used for the original transaction, unless otherwise agreed.

Return Shipping Costs

Return shipping costs are borne by the Customer, except in cases of:

  • verified defective products,
  • errors attributable to Vacuum Tubes Treasures.

In such cases, return shipping costs will be fully covered by us.

Damaged or Incorrect Items

If the Customer receives a damaged or incorrect item, it must be reported within 5 (five) working days from delivery, by email or telephone, clearly stating the issue.

Uncollected Parcels, Storage, and International Shipments

It is the Customer’s responsibility to monitor the shipment and promptly arrange for collection or customs clearance.
Any costs, delays, or losses resulting from:

  • failure to collect the parcel,
  • prolonged storage,
  • abandonment of the parcel at customs,

do not entitle the Customer to any refund.

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

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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.

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