ECC83 / 12AX7 GAP/R COMPUTOR by TELEFUNKEN Tubes - Ribbed Plates Diamond <> Bottom Made in Germany '60s
AMPLITREX Tested –Matched Pair – Low Noise & Microphonics – Vintage TELEFUNKEN Production
Test Results
Tested on AMPLITREX AT-1000 Tube Tester
Voltage Test: Va = 250V, Vg = -2V
Average 100%: Gm = 1600 ; Ia = 1.2 mA
TEST RESULT: VERY STRONG
Tube 1:
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Section 1: Gm = 1700 ; Ia = 1.0 mA
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Section 2: Gm = 1500 ; Ia = 0.8 mA
Tube 2:
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Section 1: Gm = 1800 ; Ia = 1.2 mA
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Section 2: Gm = 1600 ; Ia = 1.1 mA
Additional Tests Performed:
- Burn-in / Stability Test: 48h – OK
- Microphonics: Low Noise & Microphonics – Tested and compliant for use in hi-fi systems and guitar amplifiers.
- Balance: Good. The sections show consistent balance, fully compatible with use in hi-fi and musical amplifiers, in all applications where absolute symmetry between sections is not required.
- Emission Quality: Excellent – Very strong and stable emission, without fluctuations.
- Shorts and GAS: Absent.
Description:
Premium Matched Pair of ECC83 / 12AX7 GAP/R COMPUTOR produced by TELEFUNKEN, authentic German production Made in Germany from 1962, characterized by the sought-after Ribbed Plates construction and the unmistakable Diamond <> Bottom, the diamond embossed in the glass between the pins that identifies original Telefunken productions.
The GAP/R COMPUTOR branding makes the pair particularly interesting, but the internal construction and the distinctive diamond on the bottom confirm the authentic TELEFUNKEN origin. The code GI places production in December 1962, a particularly valued period for German ECC83s intended for audio and professional applications.
The tubes have been carefully tested and selected in our laboratory using the Amplitrex AT-1000 Tube Tester, achieving a VERY STRONG classification. The transconductance values of the four sections range between 1500 and 1800, with anodic currents between 0.8 and 1.2 mA, showing good overall balance and excellent consistency between the two units.
The pair also passed a 48-hour Burn-in / Stability Test and was selected for Low Noise & Microphonics, making it particularly suitable for hi-fi systems and guitar amplifiers. Emission was found to be very strong and stable, with no fluctuations, shorts, gas, or detected anomalies.
Sonically, the Telefunken ECC83 Ribbed Plates are particularly appreciated for their transparency, definition, and precision, with a very natural midrange, controlled bass, and open, detailed high frequencies without excessive aggression. The soundstage is orderly, focused, and rich in detail, characteristics that have made these productions a benchmark among vintage European ECC83s.
Ideal for hi-fi preamplifiers, integrated amplifiers, line stages, compatible phono stages, tube DACs, and guitar amplifiers that use ECC83 / 12AX7. The good balance of the sections allows for very versatile use in audio and instrumental applications, in all cases where absolute symmetry between the two triodes is not required.
The tubes are Vintage, carefully tested, and fully functional. Aesthetic conditions are good, with partially eroded but still legible markings and a well-preserved tube body. They are supplied in our custom boxes for optimal protection.
A premium Matched Pair of GAP/R COMPUTOR ECC83 / 12AX7 by TELEFUNKEN Ribbed Plates Diamond <> Bottom from 1962, genuinely tested, selected, and matched by Vacuum Tubes Treasures, ideal for those seeking authentic vintage German Telefunken, very strong and selected for Low Noise & Microphonics.
Condition:
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Condition: Vintage Tubes - Tested and fully functional. Supplied in our custom box for optimal protection.
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Functionality: Fully operational.
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Aesthetic condition: Good – Markings partially eroded, but still legible. Tube body in good condition. See photos for details.
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Manufacturing Code: GI – TELEFUNKEN production December 1962 - Diamond embossed in the glass between the pins.
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