The Bryston 4B amplifier was _the_ audiophile gear in early 1970’s-80’s, when _The Audio Critic_ declared it “the best power amplifier we’ve been able to find so far”, praising it as an “unflappable voltage source with an unshakably tight bass response”. Studio engineers and concert pros liked the Bryston 4B NRB for its ruggedness, and reliability and it is a standard tool for recording engineers and touring musicians. The design has been updated since it’s launch, but it has always been in production.