ECC88 / 6DJ8 MULLARD Blackburn Large Halo Getter - Matched Pair - GA1 B1F - AMPLITREX Tested - Made in Great Britain '50s

ECC88 / 6DJ8 MULLARD Blackburn Large Halo Getter - Matched Pair - GA1 B1F - AMPLITREX Tested - Made in Great Britain '50s

Description:

This pair of ECC88 / 6DJ8 MULLARD comes from the historic Blackburn factory (UK) and belongs to the original production of the 50s, identified by the manufacturing code GA1 B1F , identical on both specimens.

The presence of the Large Halo Getter and the typical first generation Blackburn internal structure make this pair particularly sought after by enthusiasts of authentic pre-Philips rebranding Mullard productions.

The aesthetic condition is excellent, with well-preserved silkscreens and intact internal structure. These are used tubes, selected and tested on the Amplitrex AT-1000 , with stable and consistent electrical results.

A true original English production, not a reprint, not a modern selection.

Stable output, regular behavior, no anomalies detected.

The matching between the two valves is correct for hi-fi use, with identical production and code.

Sound Character

Mullard Blackburn '50s are known for their rich, harmonically dense, and natural tone.

Bass: full but controlled, with excellent structure on the fundamentals.

Mids: the real strong point — warm, textured, three-dimensional, with extremely realistic vocal reproduction.

Highs: soft and refined, never aggressive, with a fine, silky texture.

Dynamics: fluid, musical, with clearly perceptible micro-contrast.

Soundstage: deep and enveloping, with excellent central focus.

It is a valve that favors timbral coherence and naturalness over artificial brilliance.

🎧 Use in Hi-Fi Amplifiers

Particularly suitable for:

• Line and phono preamplifiers
• Quality driver stages
• Tube DACs
• OTL and hybrid amplifications

Perfect for those looking for an authentic musical presentation, with a classic British feel.

🎸 Use in Music Applications

Interesting in instrument circuits and contexts where a softer and more progressive response is appreciated, with natural compression.

🎯 Note for audiophiles and technicians

The Mullard Blackburn Large Halo productions of the 1950s represent one of the most iconic expressions of the original British ECC88.

This pair, with identical code GA1 B1F , retains production coherence and distinctive sonic character.

This is not a NOS selection, but an authentic and stable pair, with solid and musically engaging performance — ideal for those who want to enter the world of vintage Mullards with a genuine and properly tested example.

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Test Results

Tested on AMPLITREX AT-1000 Tube Tester

Voltage Test: Va = 90V ; Vg = -1.2V
Average 100%: Gm = 12.5 ; Ia = 15.0 mA
TEST RESULT: STRONG

Valve 1:

• Section 1: Gm = 11.44 ; Ia = 13.8 mA
• Section 2: Gm = 11.00 ; Ia = 12.3 mA

Valve 2:

• Section 1: Gm = 10.20 ; Ia = 10.0 mA
• Section 2: Gm = 10.00 ; Ia = 10.3 mA

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

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Conditions:

• Condition: Vintage tubes - Tested and in perfect working order. Shipped 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: GA1 B1F → GA x indicates an ECC88 with the sequential progression of x, where the increment of x indicates the production changes - B1F B → Mullard, Blackburn - 1 (out of three digits) → 1951 - F → June

Find out why our valves are different →