BHK Mono 300 Power Amplifier

When you are unwilling to compromise performance we offer the BHK 300 Signature 300 watt Monoblock power amplifiers. They are among a rare handful of amplifiers capable of uncovering music's rich tapestry in a lush, uncompromised, effortless presentation.

The audio performance and build quality of the Signature 300 series has been refined, honed, and polished over the past half century of design work by industry legend, Bascom H. King. They are mono block amplifiers that produce 300 watts into 8Ω, 600 into 4Ω, and a whopping 1,000 watts into 2Ω. The BHK Signature 300 Monoblock designs are built upon two proven topologies: a zero-loss vacuum tube input stage coupled to a high bias differentially balanced MOSFET output. If you are uncomfortable with compromise and seek the finest performance, reliability, and build quality, the BHK Signature 300 series is a perfect fit that can drive any loudspeaker to musical perfection.

Design

The hybrid vacuum tube/MOSFET design of the BHK Signature Amplifiers provides stunning musical performance through any loudspeaker.The Signature 300 Mono doubles the output current of the 250 Stereo, and doubles the tubes, power supplies, transistors, capacitors and resistors. The results are hard to put into words. Your first listen to these extraordinary monoblock amplifiers will likely be a revelation. For perhaps the first time you'll discover all that has been long buried in your musical collection. You'll know this amp was the right choice from the very first note you play.

Application

The BHK Signature 300 Mono Amplifier is one of only a rare handful capable of uncovering music's rich tapestry in a lush, uncompromised, effortless presentation. If you haven't any barriers to perfection, the BHK 300s are perfect for any size system in the world, producing a minimum of 300 watts into 8Ω, a minimum 600 watts into 4Ω, and an astonishing 1000 watts into 2Ω. Enough linear amplifier power to bring life to music as you've only experienced with live music.

Technology

Overview

The importance of the power amplifier in the 2-channel system chain cannot be overstated, yet it's often overlooked. It's the rare few music lovers that truly appreciate the power amp's critical role in preserving music's nuanced details, because most amplifiers fail to preserve them. Overtones from plucked instruments, subtle cues defining placement, depth, soundstage width, and transient decays are often lost in the power amplifier. Suddenly revealed are the tiniest of details that now ring clear through the BHK, perfectly preserved through its low feedback, vacuum tube and MOSFET design. When it comes to musically controlling and powering loudspeakers, the BHK Signature 300 has no peer. The Signature 300 monoblock amplifier produces 300 watts into an 8Ω loudspeaker, 600 watts into 4Ω, and 1,000 watts into 2Ω, providing unfettered and unrestricted dynamics and musical ecstacy that only a rare few are able to enjoy.

Input Stage

A power amplifier’s input stage is a critical interface in the quest to preserve music’s essential details and vacuum tubes do it best. Hand matched pairs of Russian Gold Lion 6922s provide the perfect interface between the delicate musical transitions output by the DAC or preamplifier, transferring it without loss to the MOSFET output power stage and eventually the loudspeakers. The hybrid approach used in the BHK Signature takes advantage of the best traits technology has to offer, unavailable in traditional solid state or tube designs. While vacuum tubes are the perfect input stage, they cannot make the same claim on a power amplifier's output. Conversely, solid state designs are correct for output stages, but suffer when used as inputs. Only a hybrid approach takes advantage of the best in both disciplines.

Output stage

A power amplifier connects its reservoir of energy to the loudspeaker through a type of valve (solid state or vacuum tube) controlled by the input stage. If the input stage has done a good job of preserving music's subtle details, textures, timing and phase information, transferring it without loss to the power stage and eventually the loudspeakers is best handled by a tube-like solid state device known as a MOSFET. Not all MOSFETs are the same, their differences characterized by their relationship with the input signal and the power supply driving them: N-types for the positive going signals, P-types for negative. N-types have lower distortion and perform better than P-types but N-channel-only amplifiers are rare. Using only N Channel MOSFETS in its output stage, the BHK Signature produces a near-perfect balanced waveform without the degradation inherent in a complementary design.

Features

• Zero-loss parallel vacuum tube input stage

• Fully paralleled inside (not like a traditional bridged approach)

• Differentially coupled, paralleled, balanced MOSFET output stage

• All through hole construction (no surface mount parts)

• RCA Single ended input

• XLR balanced input

• 300 watts 8Ω

• 600 watts 4Ω

• 1000 watts 2Ω

• Less than 0.1% thd 20Hz to 20kHz at rated power

• Damping factor 100 for excellent loudspeaker control

• Front panel standby button for vacuum tube input

• -3dB greater than 200kHz

• Dual, custom, solid copper, gold plated output binding posts

• Fully balanced from input to output

• 83 pounds

• Input 12 volt trigger

• Easy access for tubes

Specifications

BHK Signature 250 Stereo and BHK Signature 300 Mono
Unit Weight	83 lbs [37.6 kg]
Unit Dimensions	17.1” x 8.7” x 14” Chassis only. 15″ deep including connectors.
Shipping Weight	92 lbs [41.7 kg]
Shipping Dimensions	21”x 13” x 19”
Color Options	Black Silver
Voltage Options Factory set only	Japan 100V North America 120V Europe/Asia/Australia/New Zealand 230V
Mains Power Inputs	IEC C14
Fuse Compliment all Countries	4 – 10 amp fast blow H-Rated 5x20mm Rail Fuses
Fuse Compliment Mains	100vac Countries 1 – 2 amp slow blow H-rated 5x20mm 1 – 12 amp slow blow H-rated 5x20mm 120vac Countries 1 – 2 amp slow blow H-rated 5x20mm 1 – 10 amp slow blow H-rated 5x20mm 230vac Countries 1 – 1.6 amp slow blow H-rated 5x20mm 1 – 5 amp slow blow H-rated 5x20mm
Accessories Included	US (NEMA 5-15P) (all versions) Schuko (CEE7/7) (230V version) UK (BS 1363) (230V version)
Audio Inputs	RCA (Unbalanced) XLR (Balanced)
Speaker Outputs Signature 250	Gold plated copper binding posts (2 pair per channel)
Speaker Outputs Signature 300	Gold plated copper binding posts (2 pair)
Other	DC Trigger Input 3.5mm 5-15VDC
Warranty	3 years parts and labor on unit 1 year on vacuum tube
Power Consumption
@Ready	75 Watts
@Idle	175 Watts
@Rated power 8Ω	850 Watts
@Rated power 4Ω	1600 Watts
Signal
Gain	30.5dB +/-0.5dB
Sensitivity for rated output power of 250 watts into 8Ω	1.3V
Noise	100-20KHz <-85dBV
Input impedance Signature 250 stereo	Unbalanced 100KΩ Balanced 200KΩ
Input impedance Signature 300 mono	Unbalanced 50KΩ Balanced 100KΩ
Output Impedance	50Hz, 2.8VRMS <0.1Ω
Frequency Response	@2.8VRMS 10Hz – 20KHz +/- 0.1dB 10Hz – 200KHz +0.1/-3.0dB
THD&IM
1KHz, 1W/8Ω	<0.01%
20-20KHz, 1W/8Ω	<0.1%
1KHz, 200W/8Ω	< 0.1% (120VAC Mains input)
1KHz, 400W/4Ω	< 0.1% (120VAC Mains input)
Signature 250 Stereo Amplifier
Output Power	Both channels driven 120vac mains, 1kHz, 1% THD
8Ω	250W minimum
4Ω	500W minimum
2Ω	Stable for musical transients
Signature 300 Mono Amplifier
Output Power	120vac mains, 1kHz, 1% THD
8Ω	300W minimum
4Ω	600W minimum
2Ω	1000W

Reviews

INDUSTRY

I’ve heard this amplifier in several systems…over the past couple years, and came away incredibly impressed on every occasion. An effortless presentation to every recording is a hallmark of PS Audio in my experience, with speed, dynamics, and an innately natural, unforced sound to everything from heavy metal, to intimate acoustic guitar solos. King seems to have harnessed the best of both worlds (tubes, and solid state) in this design, and the fact that it’s made in the USA by real people, for living wages is further proof of company founder Paul McGowan’s commitment to delivering high...

READ MORE

Parttime Audiophile-Rafe Arnott

They have truly exceptional imaging, depth, and natural soundstage width, and they really can get the best out of the naturally miked and produced recordings that have a real-world soundstage. The 300s’ dynamics are extraordinary, particularly in the lower octaves that seem to be in even more demand for audio reproduction today than the upper octaves.

READ MORE

The Absolute Sound-Anthony Cordesman

The fact is, the BHK Signature 300 is a powerful, nimble-sounding amplifier that immediately drew me in with fast, punchy, tight bass; rich, liquid mids; and delicate, transparent highs—all effectively well integrated into a coherent whole. READ MORE

Stereophile Magazine-Michael Fremer

When PS Audio decided to re-enter the amplifier market with a statement product, I am not sure even Paul McGowan anticipated what would result. That they have succeeded in creating something special is clear from my listening. The process of bringing on board a legendary designer and allowing him freedom to design to a sonic target while keeping costs in the realm of reasonable (ahem!) is more than mere advertising hype. At nearly $15k for a pair, these are not highly affordable products but they are superior to any amp I’ve heard in my room, or most other rooms for that matter. How many...

READ MORE

Hifizine-Patrick Dillon

PS Audio’s BHK Signature 300 Mono amplifiers produced wonderfully clear sound in my room, yet with a tangible, 3D quality that gave the music emerging from my speakers a bit more body -- which I really enjoyed. Their soundstaging was exceptional, and they proved unflappable throughout the listening period, despite being challenged with complex music and punishing volume levels. Their treble response was clean without sounding edgy, allowing me to enjoy longer listening sessions than I have with any other amp. I also appreciated the BHK Signatures’ tight-fisted bass reproduction, which...

READ MORE

Soundstage!-Erich Wetzel

The BHK Signature 300 Amplifier are nothing less than world-class amplifiers: Sonically they leave nothing to be desired, as they combine in perfect style power and control with softness and emotion. And PS Audio circuit Bascom H. Kings packed in simple and well designed housing instead of aluminum sculptures, the Monos can decorate with an unprecedented low price / sound ratio: downright reasonable dream amplifiers!

READ MORE

Hi Fi Statement-Dirk Somer

The PS Audio BHK Signature 250 has everything that one would expect from a power amplifier of this category: it’s powerful, fast, accurate, gentle regarding its ability to convey the harmonic complexity of even the most difficult audio tracks and has a great dynamic reserve. Its ability to recreate a coherent and well focused soundstage puts this product among the best power amplifiers regarding this parameter. I could go on for a while extrapolating specific parameters and writing about how well the BHK behaved respect to them, but it would be useless. In my opinion the ultimate reason of...

READ MORE

Fedeltà del Suono-Giulio Salvioni

Yes, it's all things you'd expect from a top flight amplifier: powerful and precise, fast and dynamic, generous in its staging, and close in its focus. But its ability to translate those elements into a musically coherent and consistently compelling performance is what sets the BHK Signature apart from any other power amplifier I've listened to. I sense a classic in the making.

READ MORE

Audio Video Magazine-Deon Schoeman

AWARDS

2019 Class A Ranking from Stereophile

2018 Recommended Component Award from Stereophile

2017 Recommended Component Award from Stereophile

2016 Recommended Component Award from Stereophile