Tube Amplifiers : RCA 50, WE 271A & WE 300B

RCA 6F8G - RCA 50 // RCA 5Z3    ver. 11/24/2021

WE 262B (刻印・メッシュ x 2) - WE 271A (刻印 x 2) // WE 274B (刻印)    ver. 05/01/2020

WE 310A small punch (Aug.'40/Aug.'39) - WE 300B (5639 x 2) // WE 274A (6713)    ver. 09/21/2019