9 pin, magnoval, B9D valves bases. Valves bases used by PL519, 6CJ3, EL504, EL509, EL502, 6LQ6, 7868... SK9DC1: Ceramic Chassis mount, B9D, 9 pin, Magnoval valve base, nickel platedA less common type of valve base, magnoval bases fit valves such as the PL519, 6CJ3, EL504, EL509, EL502, 6LQ6, 7868... A larger base than the B9A,… SK9DC1G: Ceramic Chassis mount, B9D, Magnoval valve base, 9 pin, gold platedA less common type of valve base, magnoval bases fit valves such as the PL519,6CJ3, EL504, EL509, EL502, 6LQ6, 7868... A larger base than the B9A,…