RCA 6146 Brown Base Vintage Vacuum Tube NEW with box. Tested NOS on a professionally calibrated TV7U tube tester
Fine pair of Sylvania 5692 brown base tubes, labeled for Westinghouse, with original boxes. Gm matched to about 9% difference on the Amplitrex AT1000. Shiny black plates, micanol bases, multiple support rods, thick glass, triple micas, and double getters all make for a bulletproof tube.
Up for sale is a vintage Tung-Sol 6SU7GTY vacuum tube featuring desirable black glass construction and brown micanol base. This tube is marked “AGED 48 HOURS”, indicating factory quality-control aging and testing prior to release. The 6SU7GTY is a premium low-noise industrial and military-grade tube highly regarded by collectors, audiophiles, and vintage electronics enthusiasts. Details: * Manufacturer: Tung-Sol * Tube Type: 6SU7GTY * Brown Micanol Base * Black Glass Construction * Marked “AGED 48 HOURS” * Made in U.S.A. Condition: * Untested due to lack of testing equipment * Getter flash remains intact * No cracks or chips observed
These are the extremely rare and impossible to find Dark Brown base variation. Both tested NOS on an Amplitrex AT1000 tube tester with the following results (as photographed): Tube 1- 91/91% ip 100/100% gm Tube 5- 121/126% ip 112/112% gm
Constructed with black plates, brown base, and top getter. Original box shows shelf wear/split top.