Western Electric 91E Triode Power Amplifier – An American Classic

All Image Credit: Western Electric

Western Electric is arguably Americas oldest audio company, being founded in 1869. In 2022 it launched its current 91E valve stereo power amplifier using their 300B triode valve.

The 91E is a modern development of the 91A, a single-ended triode (SET) design that was launched in 1936 and originally used in cinemas. It now uses the 300B triode valve that was originally launched in 1938 to amplify telephone signals and which resumed production in 2020.

Made at the company’s headquarters in Georgia, the 91E is a wonderful blend of modern technology and techniques with Western Electric’s 150+ years of audio experience. Merging LCD displays, Bluetooth technologies and microprocessor and remote control with its single -ended (SE) Class A triode design. Wired connectivity is plentiful coming with; four line-level RCA inputs, a MM/MC phono input and two line level outputs.

The single ended triode (SET) Class A design provides up to double the power output of a traditional SET amplifier by using their patented (US Patent 10256776) fully linear, steered constant current source (SCCS), that is controlled exclusively by the tube’s output voltage. This technique eliminates the need for large output transformers and the hysteresis that comes with them.

Other modern user and convenience features include; the microprocessor-controlled valve warm-up and auto-bias functions, the optical-encoder volume control that uses a relay-switched resistor network and the switching of filament polarity each time the amp is turned on – helping to enhance the 300Bs’ lifespan. The main output transformer comes standard as 8Ω but is pluggable allowing for optimal loading for 4Ω, 8Ω and 16Ω speakers. The front panel supports the on/off button, volume control, LCD display, input selection buttons and headphone output. With the controls status displayed on the dimmable color LCD display that shows the selected input, attenuator level and acts as a VU meter. It also displays the setting that can be adjusted by the included remote control such as; input levels, balance, and display dimming.

Rear panel connectivity includes; two pairs of speaker binding posts, six pairs of unbalanced gold plated RCA inputs, two pairs of unbalanced gold plated RCA outputs (line/pre out), Ethernet and USB ports plus the BT antenna. The phono input may have its resistive and capacitive load adjusted using the two phono load RCA’s.

Finally, any improvements in the firmware or software may be uploaded via the Ethernet or USB connections.

Features At A Glance: