5963 / ECC82 NOS GE AMPLITREX Matched Pair Long Gray Plate Horse Shoe Getter USA

5963 / 12AU7 / ECC82 NOS Stromberg Carlson by GE Long Gray Plates Horse Shoe Getter Made In USA '1959 AMPLITREX Matched – Low Noise & Microphonics – VERY STRONG – Vintage American GE Production Test Results: Tube tested on AMPLITREX AT-1000 Tube Tester: Test Conditions: Va = 250V ; Vg = -8.5V Average 100%: Gm = 2200 ; Ia = 10.5 mA Test Result: VERY STRONG Tube #12: Section 1: Gm = 2800 ; Ia = 14.2 mA Section 2: Gm = 2600 ; Ia = 12.6 mA Tube #7: Section 1: Gm = 2800 ; Ia = 13.6 mA Section 2: Gm = 2700 ; Ia = 12.8 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. Noise: Low and well-controlled. Quiet operation in hi-fi environments and in musical amplifiers in the intended positions. Matching: Very good. The sections are consistent and well-aligned, making the tube also suitable for use as a phase inverter in hi-fi and instrument applications. Emission Quality: Excellent – Very strong and stable emission, without fluctuations. Shorts and GAS: None. Description: An important NOS pair of 5963 Stromberg-Carlson tubes manufactured by General Electric, made in the United States in the 26th week of 1959. The construction with Long Gray Plates and the characteristic Horse Shoe Getter belongs to the late 1950s American GE production, making this pair particularly interesting for its build quality, performance, and historical charm. The code 59-26 188 confirms the manufacturing date and General Electric origin: 59-26 indicates the 26th week of 1959, while 188 is the EIA code assigned to General Electric. The Stromberg-Carlson branding identifies production intended for the historic US electronics manufacturer; the EIA code and internal structure clearly document the GE manufacture. The two tubes form an Amplitrex Matched pair with very homogeneous transconductance values, between 2600 and 2800 µmhos, significantly higher than the nominal reference of 2200 µmhos. Anodic currents, between 12.6 and 14.2 mA, also confirm particularly vigorous and regular emission. The 48-hour burn-in verified the stability of the parameters without fluctuations. The pair features low microphonics, low noise, absence of gas, and no shorts. The very good balance and consistency of the sections make it suitable for hi-fi preamplifiers and drivers, headphone amplifiers, buffers, line stages, and musical instrument amplifiers, as well as for use as a phase inverter in 5963-compatible equipment. In terms of sound, these GEs offer a clean, balanced, and authoritative reproduction, with natural mid-range, solid and controlled low frequencies, and defined highs without being harsh. In hi-fi systems, they promote transparency, image stability, and channel consistency; in guitar amplifiers, they ensure a responsive performance, good control, and excellent articulation. A high-level offering for those seeking an American NOS pair belonging to the same lot, with Long Gray Plates, Horse Shoe Getter, low microphonics, emission clearly superior to nominal values, and a particularly homogeneous electrical selection: two authentic Stromberg-Carlsons produced by GE in 1959, individually tested and ready for use. Conditions: Condition: NOS - New Old Stock - Tested and functional - Supplied in our custom box for optimal protection. Functionality: Perfectly operational. Cosmetic condition: Excellent – Markings well preserved, minimal signs of age. See photos for details. Manufacturing Code: 59-26 188 → RMA/EIA Open Date Code → manufactured in the 26th week of 1959 - 188 → General Electric Company, Syracuse 1, N. Y. Discover why our tubes are different →