top of page


The Bryston 21B³ amplifier is made up of a 7B³ and a 4B³ amplifier, which provides 3 channels of clean Bryston power for an active 3-way loudspeaker like the Model T Active or Middle T Active. Two of these amplifiers will drive a Bryston Active Loudspeaker System with breath-taking ease and clarity.


600W into 8Ω (1st Channel)

900W into 4Ω (1st Channel)

300W into 8Ω (2nd and 3rd Channel)

500W into 4Ω (2nd and 3rd Channel)


Harmonic Distortion (1st Channel): ≤.005% from 20Hz to 20kHz at 600W

Noise below full output (1st Channel): -113dB single ended, -116dB balanced

Harmonic Distortion (2nd and 3rd Channel): ≤.005% from 20Hz to 20kHz at 300W

Noise below full output (2nd and 3rd Channel): -110dB single ended, -113dB balanced

Slew Rate: >60V/µS

Power Bandwidth: .5Hz to >100kHz

Damping Factor: >300 at 20Hz (8Ω)



Balanced and Single Ended audio inputs

Selectable gain at 23 or 29dB

No fans or other moving parts

Regulated power supplies to all voltage gain stages

Convection cooled and housed in a fully aluminum chassis

Independent power supplies for each channel

Energy storage power transformers maximize dynamic range

bottom of page