6SN7 GTB NOS NIB Silvertone by SYLVANIA CHROME TOP Tested Tube Black Plates USA

6SN7GTB Silvertone by SYLVANIA – NOS NIB – Chrome Top – Black Plates – Made in USA AMPLITREX Tested – VERY STRONG – Balanced Sections – Low Noise & Microphonics Description: Single 6SN7GTB Silvertone by Sylvania tube, Made in USA production, in NOS NIB – New Old Stock, New In Box condition, selected for compatible hi-fi and musical applications requiring stability, low noise, and authentic vintage Sylvania sound character. The construction features black plates, a robust internal structure, and the classic Chrome Top, a distinctive element of American Sylvania production of that era. The Silvertone brand identifies a supply manufactured by Sylvania for Sears/Silvertone, maintaining the typical manufacturing quality of the original American production. The tube comes in its original box, with aesthetic conditions as shown in the photos. See images for all details. It has been tested on an Amplitrex AT-1000 Tube Tester with a VERY STRONG result, showing perfectly balanced sections in transconductance and very consistent anode current. It has also been selected as Low Noise & Microphonics, making it suitable for sensitive audio applications and compatible instrument amplifiers. Sonically, it offers a full, stable, and musically balanced performance, with controlled bass, natural mids, clear highs, and an organized soundstage. The character is typical of vintage American Sylvania production: solid, fluid, defined, and very reliable. Suitable for preamplifiers, driver stages, phase splitters, integrated amplifiers, hi-fi circuits, and instrument amplifiers compatible with 6SN7 / 6SN7GTB. A 6SN7GTB Silvertone by Sylvania NOS NIB genuinely tested by Vacuum Tubes Treasures, ideal for those seeking a strong, quiet, balanced vintage American tube, preserved in its original box. Test Results: Tubes tested on Amplitrex AT-1000 Tube tester: Test Conditions: Va = 250V, Vg = -8V Average 100% Gm = 2600 ; Ia = 9.0 mA Tube : Section 1: Gm = 2600 ; Ia = 9.2 mA Section 2: Gm = 2600 ; Ia = 8.4 mA Additional Tests Performed: Microphonics: Low. Tested and compliant for hi-fi use, including phono stages and guitar amplifiers. Also suitable for V1. Emission Quality: Excellent – Very strong and stable emission, without fluctuations. Shorts and GAS: Absent. Condition: Condition: NOS - NIB - New Old Stock, New In Box - Tested and functional - Supplied in original box. Functionality: Perfectly operational. Cosmetic condition: Excellent – Markings well preserved, minimal signs of age. See photos for details. Manufacturing Code: not decipherable, identifiable by construction characteristics. Late 1950s early 1960s Discover why our tubes are different →