Collection: GZ32, 5AQ4, CV593, CV2748, 52KU, 5V4G, GZ30, RECTIFIER, OCTAL

Today, let's see if we can get a summary of the GZ32 story. Let’s start with the 5V4, an older configuration of the GZ32, first introduced in 1937 rigid electrode structure. The Mullard 5V4G is a full wave rectifier with a rigid electrode cage and a maximum rectified output of 175 mA. The maximum recommended reservoir capacitor for the 5V4G is 40 µF and the minimum recommended series resistance to limit peak current flow is 100 Ohms.

Another variant is the 52KU which is the Cossor nomenclature for the GZ32 and is just the same as it’s a medium power biphasic HT rectifier designed for use in audio power amplifiers, small radio transmitters or industrial equipment. The maximum recommended reservoir capacitance for the 52KU is 32 µF and the minimum recommended series resistance to limit peak current flow is 75 Ohms.

The Mullard GZ32, first seen in 1939, is a medium power biphasic HT rectifier designed for general purpose use. The maximum recommended reservoir capacitance is 60 µF and the minimum recommended series resistance to limit current is 150 Ohms.

For all of these pin compatible and parameter equivalent devices, the glass versions are all octal based ST envelope types with an approximate envelope diameter of 40mm and a height excluding IO base pins of approximately 100mm

These devices are used in numerous classic valve hifi and guitar amplifiers as well as current devices too.