Power amplifiers stereo — Bryston 4B Cubed

The 4B Cubed is a stereo power amplifier from Bryston, built with a substantial output and wide rated bandwidth. Bryston is a Canadian manufacturer with a serious reputation for measurement-focused amplifier engineering backed by an exceptionally long warranty, and the 4B Cubed represents a serious expression of that broader house philosophy.

Key specs that matter

Input impedance is 30,000 ohms balanced and 7,500 ohms single-ended. Rated output is 300 W into 8 ohms, rising to 500 W into 4 ohms - a healthy near-clean doubling suggesting a capable power supply. Rated bandwidth is an exceptionally wide 1 Hz to 100 000 Hz. Signal-to-noise is 117 dB via XLR and 112 dB via RCA. Distortion is under 0.005% at full global feedback. At 430 x 160 x 411 mm and 27 kg it is a substantial chassis.

Sound and use context

Expect a controlled, high-output presentation with the exceptionally wide rated bandwidth suggesting careful attention to phase behaviour throughout the audible range - a capable performer reflecting Bryston's characteristic measurement-focused Canadian engineering approach.

Pairing

The 30,000 ohm balanced input impedance works with any modern preamplifier without gain-matching concerns, and the healthy doubling into 4 ohms suits a range of loudspeaker sensitivities.

Alternatives

Bryston's broader amplifier range offers alternatives at different output levels, worth comparing directly with a dealer if this model's already substantial 300/500 W output exceeds or falls short of what a specific system requires. Bryston exceptionally long warranty, among the most generous in the entire industry, reflects the brand genuine confidence in its measurement-focused engineering approach and is worth factoring into any long-term ownership cost comparison against rival amplifiers. A dealer visit remains the simplest way to compare current pricing across Bryston power amplifier catalogue, and a rigid, well-supported equipment shelf remains worthwhile given this substantial chassis weight. Overall this remains a capable, measurement-focused choice within Bryston power amplifier catalogue. Cable and stand choices matter far less at this price point than getting the basic loudspeaker pairing right. Adequate ventilation space around the chassis also helps this amplifier run reliably over long sessions. A dealer demonstration remains worthwhile before committing to any specific purchase.