EZ80 / 6V4 TELEFUNKEN Ulm Plant Diamond Bottom Halo Getter Rectifier Tube Made in Germany – FUNKE Tested
Made in Germany – Ulm Plant – Diamond Bottom – Halo Getter – Tested VERY STRONG
Description:
This EZ80 / 6V4 Telefunken is a high-quality vintage rectifier tube, produced in Germany at the historic Telefunken Ulm plant, recognizable by its code and the characteristic diamond bottom etched on the glass between the pins.
The EZ80 / 6V4 is a 9-pin miniature rectifier widely used in radios, tuners, preamplifiers, vintage hi-fi amplifiers, and compatible circuits. In this Telefunken version, the neat internal construction, the halo getter, and German manufacturing quality contribute to making it a very interesting choice for accurate restorations and vintage audio applications.
The visible code U7202602 can be interpreted as Ulm production, June 27, likely 1962, an attribution cautiously made based on the tube type, internal construction, and the production context.
The tube is in good overall aesthetic condition, with the Telefunken lettering still clearly visible and legible. Normal signs of age compatible with an original vintage tube are present. The glass is intact, the getter is well-preserved, and the diamond bottom represents an important element of Telefunken authenticity.
Sonic Characteristics
The rectifier does not intervene in the audio signal like a preamplification tube, but plays a fundamental role in the quality of the device's power supply, influencing its sound.
Bass
In compatible and correctly designed circuits, a stable rectifier like this can contribute to a sense of orderly and controlled bass, supporting the power supply without introducing noticeable instability.
Midrange
Power supply stability helps preserve a natural and consistent midrange, with a fluid and well-balanced presentation, particularly appreciated in well-maintained vintage radios and hi-fi equipment.
Treble
The overall response remains clean and composed, with a sense of order and finesse. The EZ80 Telefunken is among the most interesting rectifiers when one wishes to maintain the original character of the device without introducing unwanted alterations.
Dynamics
The very good and well-balanced electrical behavior contributes to a stable dynamic response. In compatible devices, this can translate into a more orderly reproduction, with good hold in the most articulated musical passages.
Soundstage
In vintage hi-fi applications, stable rectification can promote a more coherent and focused soundstage, with an orderly and well-controlled presentation, always depending on the device's design and the general condition of the circuit.
🎧 Use in Hi-Fi Amplifiers
This EZ80 / 6V4 Telefunken Ulm Plant is suitable for compatible devices that require an EZ80 / 6V4 rectifier, including:
- vintage radios
- tuners
- preamplifiers
- vintage hi-fi amplifiers
- audio circuits compatible with EZ80 / 6V4
It is a particularly suitable choice when a high-quality level is desired, with an original German tube, tested and verified.
🎸 Use in Musical Applications
In instrument equipment compatible with EZ80 / 6V4, this Telefunken can offer a stable and orderly response, useful when seeking reliability, control, and consistency in the power supply.
As always, usage must respect the electrical specifications of the device.
🎯 Note for Audiophiles and Technicians
This tube represents an interesting selection for those looking for a true Telefunken Made in Germany, with an authentic diamond bottom, Ulm Plant production, halo getter, and very solid test values.
The test on Funke W19 yielded a very good and well-balanced result, allowing it to be offered as Tested VERY STRONG.
This is not a generic EZ80 / 6V4, but an original Telefunken rectifier, verified and selected for those who desire construction quality, authenticity, and operational reliability in compatible circuits.
Test Results:
- Tube tested on Funke W19 Tube Tester:
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Test Conditions: Va = 60V, Vf = 6.3V
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Average 100%: Ia = 53 mA
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Test Result: VERY STRONG
Tube:
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Section 1: Ia = 49 mA
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Section 2: Ia = 49 mA
Conditions:
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Condition: Vintage Tubes - Tested and perfectly functional. Supplied in our custom box for optimal protection.
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Functionality: Perfectly operational.
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Cosmetic Condition: Excellent – Lettering excellently preserved, minimal signs of age. See photos for details.
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Manufacturing Code: U7202602 → Ulm plant production, June 27, likely 1962 based on the tube type, internal construction, and Telefunken's production context at the time.
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