Philips Miniwatt EL34 METAL BASE Tubes Quartet Tested Metrix U61B 89,5% MATCHED

Philips Miniwatt EL34Original Vintage Quartet – Professionally Tested

4 TUBES – 94–105 mA – METRIX U61B TESTED – Ia & G2 MEASURED

For sale is a genuine vintage quartet of Philips Miniwatt EL34 power output pentodes, one of the most important European audio power tubes ever produced and a classic choice for high-quality Hi-Fi and guitar amplification.

The sale includes the exact four tubes shown in the photographs. Their original Philips Miniwatt markings, glass envelopes, bases, pins and internal construction are documented in the listing photographs.

Each tube has been individually identified and professionally tested using a Metrix U61B valve analyser, with both plate current (Ia) and screen-grid current (G2) recorded.

Individual Test Results

LTL3404

• Ia: 100 mA
• G2: 16 mA
• Ia vs. reference: 100%

LTL3405

• Ia: 105 mA
• G2: 19 mA
• Ia vs. reference: 105%

LTL3406

• Ia: 94 mA
• G2: 14 mA
• Ia vs. reference: 94%

LTL3407

• Ia: 95 mA
• G2: 15 mA
• Ia vs. reference: 95%

Measured Ia range: 94–105 mA

Quartet average: 98.50 mA

Identification

The complete quartet is identified as:

LTL3404-7

Each tube also retains its own individual identification code:

• LTL3404
• LTL3405
• LTL3406
• LTL3407

Individual identification ensures that every electrical measurement remains permanently associated with the exact physical tube.

Philips Miniwatt EL34

The EL34 / 6CA7 family is one of the most famous power-output tube types in the history of valve amplification.

Original vintage Philips Miniwatt EL34 tubes are particularly sought after by enthusiasts of classic European valve production, restorers of period amplifiers and users of high-quality tube audio equipment.

Main Characteristics

• Brand: Philips Miniwatt
• Model: EL34
• Quantity: 4 tubes
• Type: Power output pentode
• Base: Octal
• Heater: 6.3 V
• Condition: Vintage, used and professionally tested
• Test equipment: Metrix U61B
• Ia measured: 94–105 mA
• G2 measured: 14–19 mA
• Quartet code: LTL3404-7
• Individual codes: LTL3404 / LTL3405 / LTL3406 / LTL3407

Professional Metrix U61B Testing

All four tubes were individually tested using a Metrix U61B professional valve analyser.

Reference operating conditions used:

• Heater: 6.3 V
• Plate voltage: 250 V
• Screen-grid voltage G2: 250 V
• Control-grid voltage Vg1: -13.5 V

Reference currents:

• Plate current Ia: approximately 100 mA
• Screen-grid current G2: approximately 15 mA

All four tubes measure within the expected EL34 operating region.

Electrical Grouping

The four measured plate-current values are:

100 / 105 / 94 / 95 mA

The quartet average is 98.50 mA, extremely close to the 100 mA reference value.

The full spread between the lowest and highest measured tube is 11 mA, with a minimum-to-maximum Ia ratio of approximately 89.5%.

For transparency, all individual measurements are provided so that the buyer can evaluate the quartet according to the biasing requirements and topology of the intended amplifier.

This listing therefore describes a professionally tested vintage quartet, rather than claiming a perfectly matched quartet.

The closest measured tubes can also be clearly identified from the individual results.

Screen-Grid Current

The measured G2 currents are:

• LTL3404: 16 mA
• LTL3405: 19 mA
• LTL3406: 14 mA
• LTL3407: 15 mA

Recording both Ia and G2 provides a more complete picture of the electrical behaviour of each vintage EL34 than a simple emission test alone.

Why This Quartet Is Interesting

This set combines:

• four genuine Philips Miniwatt EL34 tubes
• original vintage European production
• individual permanent identification
• professional Metrix U61B testing
• documented Ia and G2 measurements
• quartet average extremely close to nominal reference
• complete photographic documentation of the exact tubes offered for sale

The photographs show the exact four tubes included in the sale, including their original Philips Miniwatt markings, glass, bases, pins, internal structures and test documentation.

Shipping

The tubes will be packed with particular care using professional protective materials suitable for valuable vintage vacuum tubes.

Orders are normally dispatched within 1–2 business days after payment confirmation.

All shipments are fully tracked and handled by UPS, DHL or BRT, depending on destination, service availability and, whenever possible, the buyer’s preference.

Each tube will be individually protected with shock-absorbing material and placed inside a rigid outer shipping box.

For orders with a value above €200, shipping is always insured.

Local pickup is also available in Milan, Italy – postcode 20154.