Up for sale is a matched pair (2 pieces) of prime vintage NOS RCA 5U4GB full-wave vacuum rectifier tubes, packed in white boxes. Manufactured in the USA, these iconic rectifiers feature long black plates, a sturdy black base, a top side ring getter, and classic orange print logos. RCA’s vintage 5U4GB black plate rectifiers are famous among audiophiles and guitar amplifier enthusiasts for providing clean power delivery, outstanding voltage regulation, rich tonal warmth, and incredible reliability under heavy loads.

Both tubes have been thoroughly tested on an Amplitrex AT1000 automated valve tester at nominal reference specs (FWD = 44V, REV= 400). Forward Voltage Drop (FWD) and Reverse Voltage (REV) measurements are detailed in the table below.