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MULLARD

GZ34 / 5AR4 MULLARD NOS Brand Hammond Blackburn f32 – 4 Notches – Made in Great Britain '67

GZ34 / 5AR4 MULLARD NOS Brand Hammond Blackburn f32 – 4 Notches – Made in Great Britain '67

$377.00 CAD
$377.00 CAD
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GZ34 / 5AR4 MULLARD NOS Brand Hammond Blackburn f32 – 4 Notches – Made in Great Britain '67

Description:

The GZ34/5AR4 MULLARD NOS , Hammond brand , produced in the historic Blackburn factory (code f32) in 1967 , is an absolute reference rectifier of the British school. The Hammond branding identifies a selected supply for professional applications, while the authentic Blackburn construction guarantees the highest Mullard quality standards.

The presence of the four notches is consistent with mature production from the late 1960s and confirms its origin. This NOS model, perfectly preserved, was tested with a Funke W19 in our laboratory and fully complies with the original specifications.

Sound Characteristics

Bass: Deep, solid, and perfectly controlled. The power supply is stable even under load, with an authoritative low end that gives the system foundation and precision.

Mids: Rich, fluid, and natural. Vocals sound three-dimensional and coherent, with the typical Mullard musicality that conveys body and realism without excess.

Highs: Silky, extended, and refined. The high end is airy and never aggressive, ideal for prolonged, high-resolution listening.

Dynamics: Excellent balance between responsiveness and control. Transient response is quick yet composed, with readable microdynamics and authoritative macrodynamics.

Soundstage: Wide, deep, and stable. The soundstage is well-layered, with precise positioning and a great sense of realism.

🎧 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.

Particularly suitable for jazz, classical, vocal and high efficiency 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

This GZ34 / 5AR4 MULLARD NOS – Brand Hammond – Blackburn f32 – 4 Notches (1967) represents:

  • authentic Mullard production Made in Great Britain ,
  • Hammond selected supply,
  • professional test on Funke W19 ,
  • outstanding sound and collectible value.

A rectifier intended for reference systems and demanding collectors, for those who want the Blackburn Mullard sound in its most mature and reliable form , 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 = 100 mA
  • Section 2: Ia = 100 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 B7A1 → f3x indicates a GZ34 with the sequential progression of x, where the increment of x indicates the manufacturing changes - B7A1 B → Mullard, Blackburn - 7 (out of four digits) → 1967 - A → January - 1 → 1st week of the month

Find out why our valves 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.

  • 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.