12AX7 / ECC83 NOS NIB Amperex Bugle Boy Long Plates – Foil Getter – Heerlen 1957
AMPLITREX Tested – VERY STRONG – Low Noise & Microphonics – Balanced
Test Results:
Tube tested on AMPLITREX AT-1000 Tube Tester:
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Test Conditions: Va = 250V ; Vg = -2V
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Average 100%: Gm = 1600 ; Ia = 1.2 mA
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Test Result: VERY STRONG
Tube :
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Section 1: Gm = 1700 ; Ia = 1.3 mA
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Section 2: Gm = 1730 ; Ia = 1.2 mA
Additional Tests Performed:
- Burn-in / Stability Test: 48h – OK
- Microphonics: Low. Tested and compliant for use in hi-fi equipment and guitar amplifiers, even in the most sensitive audio stages.
- Balance: The sections are consistent and well-aligned, making the tube also suitable for use as a phase inverter in hi-fi and instrumental applications.
- Emission Quality: Excellent – Very strong and stable emission, without fluctuations.
- Short Circuits and GAS: Absent.
Description
Rare and valuable 12AX7 / ECC83 NOS NIB AMPEREX Bugle Boy, authentic Philips Heerlen Made in Holland production from 1957, featuring the highly sought-after Long Plates with Foil Getter construction, one of the most desirable configurations among early Dutch ECC83s and particularly interesting for high-end hi-fi systems and collectors of vintage European tubes.
The manufacturing code, still partially legible, reads Δ7K: the Δ symbol identifies the historic Philips factory in Heerlen, Holland, while 7K places production in November 1957. The famous Amperex Bugle Boy branding, combined with the Long Plates/Foil Getter construction and Heerlen production of the 1950s, makes this example particularly prestigious.
The tube has been carefully tested and selected in our laboratory using the Amplitrex AT-1000 Tube Tester, achieving a VERY STRONG rating. Both sections measure Gm 1700, with anode currents of 1.3 and 1.2 mA respectively: excellent and extraordinarily uniform values, highlighting a strong and optimally balanced tube.
It has also passed a 48-hour Burn-in / Stability Test and has been selected for Low Noise & Microphonics, making it particularly suitable even for the most sensitive audio stages. The excellent balance between the two triodes also makes it a very interesting choice as a phase inverter in compatible hi-fi and instrumental applications. Very strong and stable emission, with no short circuits, gas or detected anomalies.
Sonically, the early Amperex Bugle Boy Long Plates Heerlen are among the most appreciated European ECC83s for their combination of harmonic richness, naturalness, openness, and refinement. The mids are full and three-dimensional, the bass articulate and well-controlled, and the high frequencies airy and detailed, with a wide, deep, and well-focused soundstage. A musical and engaging presentation that makes these early Heerlen productions particularly sought after by tube rolling enthusiasts.
Ideal for high-end hi-fi preamplifiers, phono stages, integrated amplifiers, line stages, DACs and tube buffers, and guitar amplifiers compatible with 12AX7 / ECC83. The Low Noise & Microphonics selection also allows for its use in V1 and the most sensitive high-gain stages.
The tube is NOS NIB – New Old Stock, New In Box, carefully tested and perfectly functional, with its original Amperex box. Cosmetic conditions are good, with partially worn but still legible silkscreen printing; the upper closing flap of the box is missing, as visible in the photographs.
A rare AMPEREX Bugle Boy 12AX7 / ECC83 Long Plates Foil Getter Heerlen from 1957, genuinely tested and selected by Vacuum Tubes Treasures: a NOS example of great interest, with above-reference values, exceptionally aligned sections, and Low Noise & Microphonics selection, intended for those seeking one of the most fascinating early Heerlen Dutch ECC83s.
Conditions:
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Condition: NOS - NIB - New Old Stock, New In Box - Tested and functional - Supplied in Original box. The top closing flap of the box is missing, see photos.
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Functionality: Perfectly operational.
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Cosmetic Condition: Good – Lettering partially worn, but still legible. Tube body in good condition. See photos for details.
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Manufacturing Code: barely legible on white background. ??? Δ7K - Δ → Heerlen (Netherlands), 7 (on three digits) → 1957 - K → November
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