The BHK Signature 250 and 300 power amplifiers are the culmination of one man’s half-century search for perfection in music’s reproduction. Bascom H. King has designed amplifiers for many companies, some selling in excess of $100,000, including: Constellation Audio, Marantz, Infinity, and Conrad Johnson. This is the first amplifier Bascom felt was good enough to lend his name to. It is his finest achievement in a lifetime of work.
Available in both stereo and mono models, the BHK Signature series is unparalleled in its ability to render details formerly lost in the music. The BHK Signature is a hybrid design enjoying performance benefits from multiple design techniques including, a balanced differential vacuum tube input, balanced differential MOSFET power outputs, and separate, isolated, analog power supplies feeding each.
When it comes to musically controlling and powering loudspeakers, the BHK Signature has no peer. The stereo Signature 250 produces 250 watts/per channel into an eight-Ohm loudspeaker, 500 watts/channel into four-Ohms, and stable into 2-Ohms; enough power to satisfy even the hungriest of loads.
The Mono Signature 300 doubles the output current with half the impedance of the stereo model. Each Mono Signature produces 300 watts into an eight-Ohm loudspeaker, 600 watts into four-Ohms, and 1000 watts into 2-Ohms. But more than just doubling the current, the BHK Signature 300 also doubles every internal component of the 250 into one: double tubes, double power supplies, transistors, capacitors and resistors. The results are hard to put into words. The BHK Signature 300 is a clear step above the stereo 250, on the order of 20% better, though both have the same character of sound. Both the Stereo 250 and Mono 300 are one of the best performing, musical sounding amplifiers ever made. Imagine your delight listening to either.
- Zero-loss vacuum tube input stage
- Differentially coupled balanced MOSFET output stage
- All through hole construction (no surface mount parts)
- RCA Single ended input
- XLR balanced input
- 250 watts per channel 8? Signature
- 500 watts per channel 4? Signature
- 2? stable Signature 250 stereo
- 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
This Power Amplifier was originally purchased from us, and is in excellent condition.
Please refer to specification under “Brands” on our site.
Consignment sale, no boxes
We all know that Germany manufacture some of the best cars in the world, but did you know that Germany also produce some of the best most innovative Speakers in the world? Audio Physic have been successfully manufacturing speakers for well over 25 years. Their speakers are very popular in Europe, UK and USA as evidenced by their numerous favourable reviews. Now, Audio Physic speakers are available to the Australian Audiophile at realistic prices, to suit all budgets.
Audio Physic’s catch phrase is “no loss of fine detail”. To this one should add, no loss of transparency, dynamics, and tonal balance.
Audio Physic manufacture three ranges of speakers. They are “Classic Line, High End and Reference”. As one would expect, the finish and construction of all Audio Physic speakers are exemplary and the attention to fine detail is second to none.
The “Classic Line” has only been around for a few years but has proved extremely popular amongst those that want to see their speakers as well as hear them. This range comprises of an extremely aesthetically pleasing array of finishes and materials – the classic line has proved popular amongst audiophiles, architects and even wives alike!
The range is not just developed to look good though as they feature cabinets constructed of three layers of extremely different resonant behaviour, which results in a structure which is virtually immune to self-resonance. This in turn enables the drivers to reproduce faithfully the input signal, without the cabinets having a bearing on the sound. There are four veneer finishes to choose from and a variety of attractive glass finishes on certain models. These glass finishes have no bearing on the sound quality of the speaker, which is very detailed, dynamic, with a large sound stage and non-aggressive. To complement the quality of the speaker, no less than WBT nextgen binding posts are standard.
The High End and Reference Lines are a salute to the strong history of Audio Physic speaker design: Slim, raked speakers with unique design philosophies and drivers developed specifically by the German manufacturer. These ranges incorporate even newer technologies such as Ceramic foam in the woofer chamber to allow more control, more precision and more bass, Special acoustic panels and optimised damping in the midrange driver chamber for much higher resolution, better spatial imaging and increased homogeneity and lastly thanks to their special relationship with their countryman “WBT” silver terminals and ” WBT” silver contacts in the tweeter to allow for much higher resolution, better spatial imaging and increased homogeneity.
The slim raked design of the High End Line and the Reference Line keep the philosophy of a wide sound stage alive. These slim designs make the speaker almost invisible during playback and focus completely on the finer details rather than just the speaker itself.
The Reference Line for Audio Physic continues the narrow baffle cabinet philosophy. This theory when correctly put into practice allows the speaker to disappear as far as being the source of sound, portraying a much more honest stereo image as opposed to speakers designed for ‘monitor’ purposes. This suggests the speakers are designed by genuine music lovers as opposed to engineers. Once again all drivers are designed by the highly talented Manfred Diestertich to an extremely high ‘German’ specification. The tweeter is likened by Diestertich as “the tweeter you can’t hear” as the Reference line goal is to ensure an extremely well blended and holographic sound. Unlike many high end speakers the Reference line are extraordinarily efficient, showing little problem working with low powered valve amplifiers or large solid state amplifiers alike.
True to their aims Audio Physic offer state 0f the art and value for money speakers, handmade in the German countryside of Brilon with the greatest of care and detail seen only in a few of it’s competitors.
We now have a room dedicated to Audio Physics. The latest additions are:
- Classic Compact
- Classic 5
- Classic 20 Glass
- Classic 30
These new models offer even better value with exceptional tonal balance, transparency and imaging.
Click here to view our Audio Physic range
The Oval One interconnect like all Analysis Plus cables is handmade in the USA and offers excellent value considering the design and high quality materials used.
The Oval One uses an oval braided signal conductor along with an outer shield mated to a true 75 ohm solder less RCA connector. A low loss dielectric and 100% shield coverage make this cable very quiet.
This cable is proof that Analysis Plus can design and manufacture high quality products that don’t have to cost a fortune.
What would you say to having the legendary Marantz audio quality in an exceptional value-for-money Blu-ray Disc player? Well we said ‘Yes’, and the result is the 3D-capable UD5007. Not only does it reproduce all the delicate audio details from CD and SACDs, its superb 24fps Blu-ray quality comes with BD-Live and DLNA 1.5 specifications. You can also enjoy your latest music (incl. FLAC HD) and video downloads from your PC. What’s more, you get direct YouTube Leanback and Netflix video on demand access with this player. The video streaming supports DivX plus HD and guarantees playback of DivX (.avi and .divx) and DivX Plus (.mkv). One of the main reasons why this player offers such high quality at a value-formoney price is the extreme solid construction. Firstly, the disc mechanism is centrally located and is fully shielded for fast and silent loading. Then there’s the solid cabinet, large foot, and fan-less construction to minimise vibration. On top of that, the player’s four main subsystems (mechanism, main, power supply, display) are physically separated to minimise interference. It all adds up to an unbelievable opportunity.
|D/A convertion (audio)||192 kHz / 24-bit|
|D/A converter chip (audio)||PCM1781|
|48kHz sampling||4 Hz to 22 kHz|
|96kHz sampling||4 Hz to 44 kHz|
|192kHz sampling||4 Hz to 88 kHz|
|Frequency response DVD (linear PCM)||48kHz: 4 Hz – 22 kHz|
|Frequency response CD (linear PCM)||4 Hz to 20 kHz|
|Frequency response (SACD, DVD-A)||2 Hz – 100 kHz (SA-CD)|
|Signal to Noise Ratio||115 dB|
|Dynamic Range: CD / DVD||100 dB|
|Total Harmonic Distortion (THD)||0.0025%|
• Copper plate chassis / Toroidal power transformer
• 150 Watts x 7 channels (8, 20-20kHz, 0.08% THD, 2 channels driven)
• 180 Watts x 7 channels (6, 20-20kHz, 0.08% THD, 2 channels driven)
• 7 x Balanced XLR inputs (suits AV8802 pre-amp) / 7 x RCA inputs (each selectable)
• Current feedback discrete amplifiers with high current power output
• Marantz reference-grade power supply filter capacitors and high speed, high current discrete power transistors
• Low impedance continuous drive capability / 100 damping factor
• Gold plated high grade speaker terminals
• Flasher input / DC trigger (in/out) / Remote in/out ports
• Classic Porthole with blue ring lighting
• Power consumption: 880W (in use) 0.4W (standby)
• Black finish with brushed aluminium front panel / polymer resin front sides
• 440mm x 384mm x 185mm / 18kg
Chord Electronics has launched its most advanced DAC to date. Given the acronym DAVE,
Chord”s latest-generation digital-to-analogue convertor features the very best conversion technology available, using proprietary techniques never seen before.
DAVE is a highly advanced reference-grade DAC, digital preamp and headphone amplifier. Hand-made in Kent, DAVE is based around a proprietary FPGA (Field Programmable Gate Array) offering more than ten times the program capacity of its predecessor.
At its heart lies a new (and in electronics terms, huge) LX75 version of the Spartan 6 Field Programmable Gate Array (FPGA). The FPGA”s extraordinary capability enables a number of key sonic benefits including significantly improved timing and the best noise-shaper performance of any known DAC. DAVE”s technology delivers music with unmatched reality and musicality, with an unrivalled timing response.
USB B-style: 44 kHz to 768 kHz – DXD and Quad DSD
2x optical: 44kHz to 192kHz
1 x AES: 44kHz to 192kHz
4 x Coax: 44kHz to 384kHz
Dual-data mode available
2x ultra-high-speed coax 768kHz dual-data mode for use with future-unannounced Chord Electronics products.
Maximum output voltage: 6 volts RMS
THD and noise at 2.5 volts: RMS 0.000015 %
THD and noise at 2.5 volts: 127dBA Awt (124dBA into 33 ohms)
Dynamic range at -60 dBFS 1kHz -127 dBA A wt
(No measurable noise floor modulation, no a harmonic distortion)
(Analogue distortion characteristic: no distortion for small signals)
Power requirements: mains power 80 volts to 260 volts; AC 20 watts
Click here for What Hi Fi review
Click here for Hi Fidelity review
Click here for HiFi News review
Click here for HiFi Plus review
Introducing one of the most remarkable musical instruments in the world, the BHK Signature Preamplifier. This exceptionally built vacuum tube preamplifier opens up the music and reveals nuances, life and space not previously heard on your system. It is the perfect interface between your sources and power amplifier. Designed by Bascom H. King, the BHK Signature distills Bascom’s 50 plus years of high-end audio design experience into a single masterpiece of audio amplification. “This is the best sounding preamplifier I have ever designed or heard,” and that’s saying a lot for a man of Bascom’s experience. Preamplifiers play a critical role in any separates audio system, strategically positioned between sources of music: CD players, phono preamps, DACs, tape recorders and tuners – and your power amplifier – the preamp serves essential roles of control and isolation. Control is simple in concept, but extraordinarily difficult to design in an acoustically transparent manner. Control duties such as input switching, volume, balance, and amplification can place unwanted acoustic thumbprints on the music if not designed with extraordinary care. The challenge in any design is to do as little damage to music’s purity as possible. Details on how each section of the BHK Signature executes control with minimal sonic impact can be found in the Overview section on this page.
High current oversized transformer
Power supplies play a critical role in the performance of any well designed audio equipment. And the key to great sounding gear is to keep the impedance low, and the power supplies over-built. It’s been our experience over the years that the one place designers should go overboard on–never skimping–is the all important power supply. It’s been said that amps and preamps are really nothing more than modulated power supplies. And the importance of those power supplies cannot be overstated. The BHK Signature leverages an oversized toroidal analog power supply feeding 5 MOSFET based discrete regulators. Each of the regulators is based on years of experimenting and listening to find the best sounding architecture. They are explained in the video labeled “BHK on the Preamp” on this page.
Discrete hand-selected components
Most modern audio products rely upon surface mount components to pass audio signals. PS Audio also uses sophisticated surface mount parts in our digital products because they have advantages unavailable with through-hole technology. The same cannot always be said for high-end analog electronics, like those inside the BHK Signature preamplifier. When compromise is not an option, analog audio products benefit from incorporating through-hole discrete parts in the signal path. Hand-selected through-hole PRP resistors, high grade Audiophile capacitors and the finest of discrete parts are used throughout the BHK Signature preamplifier. Nothing was spared in its design. Even the solder we use has been auditioned for best sound.
Zero loss vacuum tube input stage
The heart of any preamplifier is both the gain stage that provides the amplification and the volume control that manages how loud or soft the music plays. Inside the BHK Signature Preamp a pair of hand-selected and matched 12AU7 dual triode vacuum tubes provides the unit’s gain. The tubes are fed from a discrete MOSFET based high voltage regulator on their plates, and a discrete MOSFET constant current source on their cathodes. The filament voltage is supplied from a separately regulated supply delivering a clean source of free flowing electrons.
Resolution perfect volume and balance controls
The second most important area of a preamplifier’s performance is the mechanism used for controlling the volume. Inside the BHK Signature, a combination of a stepped discrete input attenuator is combined with a novel switched gain adjustment controlling the actual gain of the vacuum tube. This topology offers the cleanest, lowest impact gain control in half dB steps. The sonic transparency achieved by this unique architecture, coupled with the zero loss vacuum tube, are largely responsible for the remarkable levels of openness and transparency afforded users of the preamplifier.
Control of the volume is handled through the front panel haptic feedback rotary encoder, or the supplied infra red remote control.
Balanced circuit topology
Regardless of the type of input, single ended (RCA) or balanced (XLR), the vacuum tube input stage remains fully balanced for lowest distortion and highest linearity. It is instructive to click on the video link on this page labeled “BHK on Balanced Audio”. There, designer King offers insight into the value of a true balanced design, like that found from input to output in the BHK Signature instrument.
DC output triggers
Whether you’re using a pair of PS Audio’s BHK Signature power amplifiers, or any other product that can be switched on and off through a DC trigger, the BHK Signature Preamp offers two +12V outputs. Connect each DC trigger output to the DC trigger input of a compatible power amplifier or source, and control power-on duties from the front panel of the BHK Signature preamplifier.
Vacuum tube standby control
It is important for any high-end audio product to remain active for best sound quality, and the BHK Signature is no exception. Using the front panel PS logo button, the preamplifier can easily be placed in standby mode or activated to play music. When in standby mode, all the internal solid state circuitry such as the headphone amplifier, voltage regulators and high current output stage remain active, while the input vacuum tubes are turned off, thus preserving their life.
Input naming, home theater bypass
The front panel OLED display on the BHK Signature Preamplifier is deceptively simple. Touch the single button to switch inputs, or use the supplied remote control. But hold down the front panel button and you enter the setup mode. Here, HT bypass modes for each input, as well as custom input naming can be accommodated to customize the BHK Signature to your system.
Extended bandwidth and subterranean bass
Though humans, even those with the best of hearing, cannot perceive frequencies extending beyond 20kHz or below 20Hz, it is sonically critical a high-end preamplifier extend its reach beyond those limits. It has been demonstrated, time and again, that audio amplification products with extended bandwidth sound more open and natural than their frequency restricted counterparts. Reasons vary, but essentially, an unrestricted bandwidth of both high and low frequencies assures zero phase shift performance in the audio band that permits overtones their full harmonic richness and transient rise times identical to the recording – and all without compromise. The BHK Signature extends well beyond 100kHz on the top end, and well below 0.1Hz on the low end. This extended bandwidth is partly responsible for the effortless presentation of music BHK preamplifier owners enjoy.
Hear more than you ever imagined
Perhaps one of the most common exclamations we’ve heard when auditioning the BHK Signature for the first time is one of surprise at the extraordinary level of missing nuance and details revealed. There’s an old saying that we don’t know what we’re missing until it’s gone. Perhaps the corollary of that chestnut might apply to the BHK Signature. You don’t know what’s been missing until the sound is revealed.
First time listeners to the BHK preamplifier remark at how much better the space around instruments and vocals appears. Most are gobsmacked when they hear nuances like those found in subtle hall reverb cues, extended harmonic richness and detail, depth and extended soundstage width. Perhaps even more remarkable is the improvement brought by this preamplifier when placed between a DAC that had once been connected directly to the power amplifier. One school of thought suggests that fewer pieces of equipment in the signal path offer the greatest chance of achieving sonic purity. It is, after all, a logical thought that makes great sense. And, depending on the quality of the instrument added to the signal path, can often be accurate. But the BHK Signature changes that dynamic, and not in a small way. Placed between even the finest DACs in the world – with zero loss digital volume controls – the improvements in sound quality are nothing short of ground breaking. Openness, transparency, increased space around instruments and voices come alive in ways most never thought possible. Music becomes convincing, part of the soul of the listener, rather than living on the edges – appreciated cerebrally, but felt less in the tapping of one’s foot.
The BHK Signature is the culmination of one man’s quest for musical perfection, coupled with one company’s obsession to bring musical truth to as many people as it can. PS Audio has consistently sought out the finest design talent both from within and from outside, for the benefit of music lovers around the world. The BHK Signature embodies the lifelong design experience of Bascom H. King, and executed by PS Audio’s chief engineer, Bob Stadtherr – responsible for mechanizing everything inside that makes it work. A strong engineering and production team, lead by Dave Paananen, coupled with the ears, experience, and design chops of one of the legends of high-end audio, Bascom H. King, help make the BHK Signature one of the finest preamplifiers the world has ever enjoyed.
|Unit Weight||22 lbs [13.5 kg]|
|Unit Dimensions||14” x 17” x 4” [ 36cm x 43cm x 10cm]|
|Shipping Weight||31 lbs [19 kg]|
|Shipping Dimensions||20.5”x 24” x 10” [52cm x 61cm x 25cm]|
|Input Power||Model specific 100VAC, 120VAC, or 230VAC 50 or 60Hz|
|Coaxial RCA single ended
|Coaxial RCA single ended
Analog Audio Output
|Output level||4.0 Vrms|
|THD&IM @ 1KHz (full scale)||<0.03%|
|Bandwidth||-3dB 0.1Hz – 200kHz|
|S/N Ratio||1kHz >80dB|
|THD & IM 1 volt out||<0.02%|