Усилители мощности моно — PS Audio BHK Mono 300 Power Amplifier

Bascom H. King, whose initials name the BHK series, designed this single-channel amplifier for the Boulder, Colorado maker PS Audio. Tubes handle the input and MOSFETs the output, and the model left new production in 2025.

Key specs that matter

Rated output is 300 W into 8 ohm, 600 W into 4 ohm and 1,000 W into 2 ohm. Voltage gain is 30.5 dB within 0.5 dB. Frequency response is 10 Hz to 20 kHz within 0.1 dB and extends to 200 kHz at +0.1/-3.0 dB. Total harmonic distortion stays below 0.1% from 20 Hz to 20 kHz at rated power and is given as 0.01% at 1 kHz and 1 W into 8 ohm, and noise is below -85 dBV over 100 Hz to 20 kHz. Output impedance is under 0.1 ohm at 50 Hz and 2.8 V RMS. The chassis measures 43.4 cm wide, 22.1 cm high and 35.6 cm deep, or 38.1 cm including connectors.

Engineering and use context

PS Audio chose the hybrid layout to gain the strengths of tubes at the input while keeping them out of the output stage, where their limitations apply. At the front sit hand-matched pairs of Russian Gold Lion 6922 tubes. PS Audio describes the circuit as a zero-loss tube input stage coupled to a high bias, differentially balanced MOSFET output. Only N-channel parts are used there, with no P-channel counterparts - an approach that the maker says avoids the degradation inherent in a complementary design. Construction is through-hole, the circuit is fully paralleled inside, and the tubes are easy to reach for replacement. Consumption depends on load - 75 W in ready mode, 175 W at idle, 850 W at rated power into 8 ohm and 1,600 W at rated power into 4 ohm. Every unit offers RCA and XLR connections and has gold-plated copper speaker binding posts, and a 3.5 mm DC trigger jack accepts 5 to 15 V for remote switching. PS Audio covers the electronics for three years for parts and labour and the tubes for one year. The amplifier was produced in black or silver.

Pairing

As a single-channel design, two units form a stereo pair, and more units are needed for multichannel use. The trigger jack allows a preamplifier or processor with a trigger output to turn both units on together. With output rising into lower impedances, the pair can drive loudspeakers with low impedance dips, and the XLR inputs accept a balanced preamplifier.

Alternatives

The BHK Mono 600 Power Amplifier is the more powerful BHK monoblock.