WE300B Western Electric Quad matched Quartett Holz Box

WE300B Western Electric matched quad – four selected power triodes from current US production

The Western Electric WE300B is a directly heated power triode with a UX4 base and has been a reference among audio output valves since 1938. This set contains four tubes from the current US production run, manufactured to the original specifications according to the maker. Each tube passes a 72-hour burn-in and selection process, is paired in the USA and shipped as a matched quad in a wooden box.

A matched quad is the right choice wherever several valves need closely matched characteristics: push-pull output stages, stereo amplifiers, dual-mono builds or parallel single-ended circuits. According to the original data sheet, the 300B is a Class-A audio triode intended for power outputs of up to approximately 10 watts.

Typical applications

• Stereo and dual-mono single-ended 300B amplifiers
• Push-pull output stages and parallel SE circuits requiring balanced current sharing
• Retubing existing high-end 300B amplifiers
• New audio DIY builds with a properly calculated output transformer

Technical data

Valve type

directly heated power triode for Class-A audio service

Base

UX4 (4-pin)

Heater / filament

5 V / 1.2 A

Average characteristics (plate voltage 300 V, grid −61 V)

plate current 60 mA, amplification factor 3.85, transconductance 5.5 mA/V, plate resistance 700 ohms

Absolute limits (not operating points)

max. plate voltage 450 V, max. plate dissipation 40 W, max. plate current 70 mA with fixed bias or 100 mA with self-bias

Dimensions

bulb diameter approx. 61 mm, height approx. 140 mm

Selection

72-hour burn-in, matching and pairing in the USA

Scope of delivery

4 valves as a matched quad in a wooden box

Country of manufacture

USA

Application and design notes

The 300B is directly heated: with AC filament supply, the data sheet recommends returning grid and plate circuits to a center tap on the filament winding to minimize hum. Noise, linearity and distortion depend strongly on the operating point, load, output transformer, power supply and circuit topology. Lethal voltages are present in operation – construction and commissioning should be left to experienced builders.

Questions about selection and use

Is the WE300B matched quad suitable for push-pull or dual-mono amplifiers?

Yes, that is exactly what a matched quad is for: the 72-hour selection process delivers valves with closely matched characteristics, which supports balanced current sharing and symmetrical operation in push-pull stages, parallel tube systems and dual-mono blocks.

Does the Western Electric WE300B fit existing 300B amplifiers with UX4 sockets?

Yes, the WE300B uses the UX4 base with a 5 V / 1.2 A filament and the classic 300B operating data. The amplifier must be designed for 300B conditions; filament supply, bias and plate voltage should be verified before installation.

Is the current WE300B really made in the USA?

Yes, current production takes place in the USA and follows the original 1938 specifications according to the manufacturer. The quad is selected, paired in the USA and delivered in a wooden box.