Усилители мощности моно — Bryston 7B Cubed

The 7B Cubed, written by Bryston as 7B3, is a mono power amplifier in the Canadian company's Cubed Series, built in Canada and sold one unit at a time, which means two are needed for stereo. Bryston positions it for very high performance audio systems, with a professional rack version offered alongside the home model.

Key specs that matter

Rated output is 600 W into 8 ohm and 900 W into 4 ohm. Bandwidth runs from below 1 Hz to 100 kHz at the -3 dB points, and THD plus noise stays under 0.005% from 20 Hz to 20 kHz at 600 W into 8 ohm. The noise floor is -119 dB through the XLR input and -117 dB through RCA. Input impedance is 5 kohm per leg balanced and 7.5 kohm unbalanced, and gain can be switched between 23 dB and 29 dB. The chassis is 432 or 483 mm wide, 147 mm high and 394 mm deep, or 452 mm with handles, and weighs 24 kg.

Engineering and use context

Every Cubed amplifier uses the patented Salomie circuit, an input stage developed for this series. Cooling is purely by convection, so the 7B3 runs without any fan, and the enclosure is made from machined aluminium that is then anodised. Power-up is managed by a SoftStart sequence under microprocessor control, a DC trigger input allows remote power control from a partner unit, and standby draw is below 500 mW. Dual pairs of speaker terminals at the back allow bi-wiring from the single channel. The faceplate is silver or black, and the home version is not meant for rack mounting. Bryston covers the amplifier with a 10-year warranty. The PRO variant is intended for professional audio installations, where fanless operation keeps equipment rooms and control rooms free of added mechanical noise.

Pairing

Switchable gain helps fit the 7B3 to preamplifiers with different output levels - the lower setting suits a source with a high balanced output, while the higher one helps a quieter line stage reach full power. Balanced connection gives the lower of the two noise figures, so a balanced-output line stage, for example Bryston's own BR-20 or BP-17 Cubed, makes the most of the input stage. Given its power reserve into low impedances, floorstanding speakers with demanding loads are well within its range.

Alternatives

The Bryston 28B Cubed is the larger mono amplifier in the same series, with a single channel capable of 1000 W into 8 ohm.