GZ34 / 5AR4 MULLARD NOS Brand GE Blackburn f32 Copper Plates – 7 Notches – Made in Great Britain '65

GZ34 / 5AR4 Mullard NOS – Brand GE – Blackburn f32 – Copper Plates – 7 Notches –  Made in Great Britain (1965)

Description:

This NOS Mullard GZ34/5AR4 , Brand GE , produced in the historic Blackburn factory (code f32) in 1965 , represents one of the most sought-after and appreciated rectifiers ever. It is a true English Mullard , branded GE for the foreign market, but entirely built by Mullard to the highest standards of the British golden age.
Copper plate construction is a hallmark of Blackburn's finest Mullard GZ34s, contributing to a benchmark in electrical and sonic performance. The tube is NOS , in excellent condition, and has been tested with a Funke W19 , proving to be fully compliant with the original specifications.

Sound Characteristics

Bass: Deep, solid, and authoritative. The power supply is extremely stable even under load, with a well-structured low end that gives weight and control to the entire system.

Mids: Rich, fluid, and incredibly natural. Vocals and acoustic instruments emerge with a three-dimensionality and timbral coherence that made the Mullard school famous.

Highs: Silky, extended, and refined. The high end is airy and never aggressive, with a finesse that favors long, relaxed listening sessions without losing detail.

Dynamics: Excellent. Transient response is prompt yet composed, with top-notch microdynamics and authoritative, controlled macrodynamics.

Soundstage: Wide, deep, and perfectly layered. The soundstage is stable, three-dimensional, and very realistic, with precise instrument placement.

🎧 Use in Hi-Fi Amplifiers

Ideal for:

• GZ34/5AR4 compatible mid-high and high-end hi-fi amplifiers,
• quality push-pull and single-ended circuits,
• systems that seek maximum power control, natural timbre and sonic refinement.

A reference choice for jazz, classical, vocal and high-resolution systems.

🎸 Use in Music Applications

Also highly appreciated in:

• vintage instrument amplifiers and professional equipment,
• contexts where absolute reliability, stability and balanced musical response are required.

🎯 Note for audiophiles and technicians

• one of the best straighteners ever produced ,
• authentic Mullard production Made in Great Britain,
• GE Brand branding for the export market,
• professional test on Funke W19 ,
• sound, historical and collectible value of the highest level.

A valve intended for reference systems and demanding collectors, for those who want the authentic Mullard Blackburn sound , without compromise.

Test Results:

Tubes tested on FUNKE W19 Tube tester:

• Test Conditions: Va = 60V, Vf = 5V
• Good from: Ia = 55 mA
  
• Average 100%: Ia = 100 mA
  
• Test Result: VERY STRONG

Plate current:

• Section 1: Ia = 102 mA
  
• Section 2: Ia = 101 mA

Additional Tests

• Microphonics: Standard. Tested and approved for use in hi-fi and guitar amplifiers.
• 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: f32 B5D1 → f3x indicates a GZ34 with the sequential progression of x, where the increment of x indicates the manufacturing changes - B5D1 B → Mullard, Blackburn - 5 (out of four digits) → 1965 - D → April - 1 → 1st week of the month

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