PS Audio BHK Mono 600 Power Amplifier

Future Audiophile heard extensive detail, clear imaging and airy, concise upper frequencies, while Hi-Fi News praised an exemplary grasp of detail and lifelike vocal presence without airbrushing. The Absolute Sound similarly found high-frequency purity and naturalness, though it detected a slight softening at the very top, and Future Audiophile felt a Pass Labs XA60.8 had a small edge in ultimate upper-frequency detail.

The hybrid circuit is widely credited with combining the heft of a large transistor amplifier with tube warmth, harmonics and cohesiveness. Positive Feedback found the presentation warm, rich, natural and non-fatiguing, while Hi-Fi News highlighted smoothness, tonal texture, biting energy when required, and exceptionally lifelike voices.

This is the BHK Mono 600's clearest strength. The Absolute Sound called its dynamic envelope exceptional and heard large swings reproduced without compression, harshness, blur or apparent strain; Hi-Fi News likewise said it towers above lesser amplifiers with explosive power and never sounds out of breath. Other listening reports reinforce that impression with references to out-of-the-blocks slam, controlled aggression and substantial reserve power.

Reviewers repeatedly describe unusually convincing spatial performance. Future Audiophile heard a large stage extending behind and beyond the speakers, with crystal-clear, three-dimensional instrumental images, while The Absolute Sound reported exceptional width, depth, precise performer placement and unusually effective space around individual musical lines. Hi-Fi News also found the stage intensely believable.

These are substantial 108lb monoblocks with first-rate fit and finish, a massive 1.6kVA transformer, over 300,000µF of capacitance, heavy-gauge internal cabling and copper bus bars. Practical provisions include balanced and single-ended inputs, dual speaker terminals, selectable gain, trigger in/out, protective monitoring and a tube-input/MOSFET-output hybrid architecture; reviewers also note that their size, weight and heat output require thoughtful installation.

At approximately $32,500 per pair in the US and £30,000 in the UK, these are plainly elite-priced amplifiers. However, The Absolute Sound judged them to cost roughly 50–70% of competing amplifiers of comparable power, and Future Audiophile characterized them as a long-term, "cry once, buy once" purchase. Hi-Fi News notes that the price is roughly double that of the BHK 300, matching the increase in rated output.