6V6GT DELCO by Sylvania Black Plate Smoked Glass Foil Getter AMPLITREX Tested Tube USA 1952

6V6GT DELCO by Sylvania Black Plate Smoked Glass Foil Getter Tube Made in USA 1952 AMPLITREX Tested – VERY STRONG - Vintage American Sylvania Production Test Results: Tube tested on AMPLITREX AT-1000 Tube Tester: Test Conditions: Va = 250V; Vg2 = 250V; Vg = -12.5V 100% Average: Gm = 4.1 ; Ia = 45 mA Test Result: VERY STRONG Tube : Gm = 3.97 ; Ia = 40.4 mA Additional tests performed: Microphonics: Low. Tested and confirmed for use in hi-fi equipment and guitar amplifiers, including the most sensitive audio stages. Emission Quality: Excellent – Very strong and stable emission, without fluctuations. Shorts and GAS: Absent. Description: Authentic 6V6GT Delco Made in USA, marketed under the historic Delco brand and manufactured by Sylvania Electric Products Inc. at the Emporium, Pennsylvania plant. An interesting American private-label production from the early fifties, capable of combining the charm of the Delco marking with the build quality of the famous Sylvania 6V6GTs. The code 312 213 unmistakably identifies Sylvania and dates the manufacture to the 13th week of 1952. The tube features one of the most appreciated configurations of the period: black plate, smoked glass, and foil getter, accompanied by the large yellow Delco marking on the base and the 6V6GT label still clearly visible on the glass. Tested on Amplitrex AT-1000, it recorded Gm 3.97 mA/V and Ia 40.4 mA. The transconductance reaches approximately 97% of the nominal value, while the plate current stands at around 90% of the reference: results that confirm strong, regular, and stable emission, particularly valid for a production dating back to 1952. The tube passed all checks without showing fluctuations, gas, or shorts. The low microphonics allow for its use in hi-fi amplifiers, guitar amplifiers, and other vintage equipment compatible with the 6V6GT. In terms of sound, Sylvania black plates from this era are generally appreciated for an open, dynamic, and natural presentation, with well-articulated mids, controlled low frequencies, and a defined high end. A musical and energetic performance, suitable both for single-ended configurations and as an element to complete a matched pair. This is a used, tested, and perfectly functioning vintage tube. The markings are excellently preserved and the aesthetic condition is excellent, with only minimal signs of age. It is supplied in a custom Vacuum Tubes Treasures box. A 1952 6V6GT of particular historical and collectible interest, enhanced by Delco branding, authentic Sylvania black plate construction, and still very solid Amplitrex performance. Condition: Status: Vintage Tubes - Tested and fully functional. Supplied in our custom box for optimal protection. Functionality: Perfectly operational. Aesthetic Condition: Excellent – Lettering excellently preserved, minimal signs of age. See photos for details. Manufacturing Code: 312 213 → 312 Sylvania Electric Products Inc., Emporium, Pa. - 213 → 2 (from three digits) → 1952 - 13 → 13th week of the year Discover why our tubes are different →