Bryston 4B³ Stereo Power Amplifier

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  • The Bryston 4B³ is a dual channel (stereo) amplifier which is acclaimed internationally as being suited for the finest and most sophisticated sound systems. It is currently our most popular Cubed Series model.


    As a result of relentless passion for superb performance and unparalleled build quality, Bryston engineers have continued to innovate since 1976. The Cubed Series amplifiers continue this tradition of excellence, highlighted by lower distortion, increased bandwidth and reduced noise, presenting listeners with a crystal clear window into their most favorite recordings.

    Bryston Cubed Series Amplifiers, featuring patented circuitry, move the listener ever so close to the music with such visceral realism, the experience is most comparable to live performance.


    Bryston engineers, have been busy over the years finding new methods to reduce noise and distortion to reveal more nuance and subtlety than ever before. Cubed Series amplifiers employ significant improvements including:

    • Dramatically less distortion at input stage
    • Improved common mode noise rejection
    • Major improvement in EMI/RFI noise rejection
    • Less than 500mW standby power consumption
    • Update dress panel aesthetic with clean lines and new finish.
    • Extreme Clarity and Detail

    All Cubed Series amplifiers feature a new patented input circuit that is precisely optimized and linear beyond any we’ve used before. Featuring twelve active devices in a groundbreaking array, this new circuit both matches the amplifier to virtually any preamplifier and provides the first 6dB of gain. The new input stage is so transparent, its measurable distortion is less than 1/1000th of 1 percent!

    Newly designed circuitry in the Cubed Series amplifiers is virtually impervious to noise such as RFI and others induced by external and environmental causes.

    The Quad-Complementary topology improves linearity to a new standard of accuracy while virtually eliminating aggressive higher harmonic distortion byproducts. The overall harmonic distribution of Bryston’s Quad-Complementary output mimics the characteristics of a class-A design but with dramatically lower distortion. Each amplifier channel includes its own fully independent power supply with separate transformer.


    Cubed Series amplifiers employ design innovation to achieve superior performance, yet so much has remained constant through years of evolution. Each amplifier is manufactured in our state-of-the-art facility located in Peterborough, Ontario Canada utilizing many locally sourced components. Many members of the Bryston team have been with the company for decades and take great pride in their highly specialized craft.

    All Bryston products are proven on our test bench for one hundred hours of burn in before shipping. Amplifiers cycle between full power and idle in thirty minute intervals to uncover any anomalies that could be illuminated by thermal stress. Our reputation for reliability is without peer.

    Not only do our amplifiers undergo pass/fail testing, but each must achieve excellence in performance benchmarks as well. With each Cubed Series model, the customer will receive a comprehensive performance certificate detailing the exact specifications of the amplifier.

    To demonstrate our commitment to excellence and performance, every Bryston amplifier is warranted to be free of defects in materials and workmanship for a full twenty years.


    All amplifiers are available in either C-Series or PRO versions. C-Series models are available in black or silver colored dress panels and 17 or 19 inches wide. Nineteen inch wide models include front mounted handles (add 1.6 inches to listed depth).

    PRO models are always black and include rack mountable 19 inch wide dress panels plus front mounted handles (add 1.8 inches to listed depth). PRO models also include individual channel trim pots on the rear panel.

    • Active extremely low distortion input buffer
    • Balanced and unbalanced inputs
    • Selectable gain at 23 or 29dB
    • Regulated power supplies to all voltage gain stages
    • Independent power supplies for each channel
    • Convection cooled and housed in a fully aluminum chassis.
    • No fans or other moving parts
    • Bridging switch configures amplifier into a single 900W Channel
    • Harmonic Distortion: < .005% from 20Hz - 20kHz at 300W
    • Noise below full output: -110dB single ended, -113dB balanced
    • Slew Rate: < 60V/µS
    • Power Bandwidth: .5Hz - > 100kHz
    • Damping Factor: > 500 at 20Hz (8Ω)
    • Gain: Switchable - 23dB or 29dB
    • 300W into 8Ω
    • 500W into 4Ω
    • 900W into 8Ω (Bridged Mono)
      • Available with silver or black faceplate (3U + .55”)
      • 17” (without handles) or 19” (with handles) faceplate available (non-rack mountable)
      • Rack mountable Pro Edition available in black (see Cubed Pro for more details)

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