5U4GB/GA CBS OS

Description

5U4GB/GA CBS OS rectifier listing

This listing retains the CBS brand and OS designation recorded in the catalogue. OS means old stock; it must not be read as a claim that the valve is unused NOS. The combined GB/GA listing name also needs the markings on the available item checked before selecting a suffix-specific specification.

Confirm the exact valve before choosing a reference

Ask Glass Audio to confirm the full markings and available condition for your requirement. The CBS label by itself does not establish the original manufacturing factory, production date, remaining life or measured performance. No factory-origin or unused-condition claim is added here.

For comparison, the historical RCA 5U4GB reference describes a full-wave vacuum rectifier with a directly heated 5 V AC, 3 A filament and octal base. Its allowable AC input and DC output depend on the filter, load, effective supply impedance and other document conditions. That GB reference must not be applied uncritically to an item marked GA or another designation.

Compatibility and safe replacement

An octal base or shared 5 V filament voltage is not sufficient evidence of safe interchangeability. Check the exact suffix, filament demand, voltage drop, filter capacitance, equipment ratings, mounting requirements and startup behaviour against the equipment service information. Rectification is not a guarantee of voltage regulation, low hum or a particular audio character.

Glass Audio tests valves before sale. Ask about any individual measurements you need; no matching tolerance, selected noise grade or service-life figure is claimed. Valve power supplies can retain lethal voltages after disconnection, so a suitably qualified technician should assess internal servicing and replacement decisions.

Historical reference and enquiries

Reference: RCA 5U4GB archive, including tentative data dated 5 November 1954. This is a historical GB type reference, not a CBS GA specification or an individual test certificate.

Visit the datasheet library or enquire about this CBS old-stock item with the equipment model and required designation. International postage is calculated before a quote; Pretoria collection is by prior arrangement.