Rare New Old Stock (NOS), Never-In-Box (NIB) GZ34 (5AR4) rectifier valves from Mullard, manufactured in the 1950s at the legendary Blackburn factory. Full metal base construction with original getter and military-grade internal structure.

These units represent the golden era of British valve engineering — known for exceptional voltage regulation, low hum, and unmatched reliability in high-end audio amplifiers. Each is individually tested for transconductance & emission over original datasheet specifications.

Available as matched pairs or singles, with full documentation upon request.