(!!!!!) (Best Value Single) 5Z4G Tungsram UK black plates NOS 1950's smaller getter (56/40 and 56/40) (G9 Audio preamp) (Best sub for Russian 5Ц4С / 5U4C Russian)
(!!!) (Best Pair) 5Z4 Raytheon NOS 1950 (54/40 and 54/40 x 2 tubes)
(!!!) 5Z4G Brimar UK gray plates used/good 1960 era (60/40 and 62/40)
(!!!) 5Z4G Brimar UK gray plates used/good 1960 era (63/40 and 64/40)
5Z4 CBS NOS 1954 (53/40 and 55/40)
5Z4 GE Coronado NOS 1950 (48/40 and 50/40)
5Z4 GE NOS 1950 (54/40 and 56/40)
5Z4 Ken Rad NOS 1946 (53/40 and 53/40)
5Z4 Ken Rad NOS 1949 (53/40 and 53/40)
5Z4 RCA JAN NOS 1959 (51/40 and 51/40)
5Z4 RCA metal used/tests like new surface rust on metal can (52/40 and 54/40)
5Z4 RCA NOS mid-1940's (50/40 and 51/40)
5Z4 Rogers Canada NOS 1959 (51/40 and 51/40)
5Z4P Chinese (Best sub is 5Z4G or GZ30)
GZ30=5Z4GT Mullard NOS 1961 (sold out)
