PS Audio’s Paul McGowan was fortunate enough to acquire the designing prowess of renowned audio designer and guru Bascom H King to design PS Audio’s top of the line BHK amplifiers. Kudos to McGowan and to Bascom H King!

Until recently, I was content to enjoy the charms of the Rogue Audio ST-100 tube amplifier to drive my Legacy Audio Focus SE speakers full range in my large room’s reference system. But, due to a recent move across town to a larger home, I had two new listening rooms to set up in a large finished basement. Here, the new “Large Room Reference” is approximately 13’Wx22’ long with an 8’ ceiling—large enough for the Focus SE’s to breathe and fill the room with beautiful sound.

And as it happened, that is when I chanced on the opportunity to review the BHK 250 amplifier in my new room! The timing couldn’t have been better!

Features

The BHK 250 amplifier provides the usual features for a basic power amplifier, plus a few more. On the front panel the lighted PS Audio Emblem shows the amplifier is fully on, when lit, and is in Standby when off. The rear panel contains a standard pair of gold-plated RCA-type inputs as well as XLR Balanced inputs that are the preferred hookup. Both black and silver finishes are offered

Most of the internal high-quality parts are hand soldered onto BHK circuit boards and Bascom King insisted that no surface-mount parts be used in the signal path.

Two pairs of high-quality gold plated speaker binding posts are standard and could work well for bi-wiring if so desired. They are machined out of copper, polished, and then gold plated. There are also a few fuses and a Master on/off switch plus the AC IEC receptacle for use with your power cord of choice. I used a Maker Audio Reference AC cord to power the amp.

Another nice convenience feature is a small hatch plate with a built-in window so you can see the input tubes and easily replace them by removing the hatch plate (instead of the whole top cover). The amplifier comes with a hand matched pair of Russian Gold Lion 6922 input tubes. Free shipping is included in the price as well as a 30-day satisfaction guarantee

Prelude to Setup, “My Soapbox”!!

I feel it is my duty to explain the need for room correction in a high-end audio system since I’ve been using the Lyngdorf DPA-1 analog/digital pre/pro for the last five or six years.

The reality of getting any audio system to sound great is that you need great performing components and speakers, as well as acoustic tuning devices like bass traps, Room Tunes, diffraction devices (and sure, count your sofa, record albums, and other things in your room as well) to help your listening room support great sound. But if you think that these acoustic measures can nearly fix all your specific room issues I’m afraid you have been seriously misled. Just for example, what are the odds that using tube traps and furniture to control the bass will be adequate? Just so you know, it’s pretty much nearly zero. That is because the bass peaks in your room (or dips) will almost never be at the specific frequencies these acoustic devices work at, and you can count on the bandwidth of the peak and the amount of attenuation being wrong too.

So we’re in the year 2018 now, correct? Then why not use computerized DSP to get you a lot closer to the curve that would actually be of great help in your particular system and room? And heck, if you’re into computer audio and use a media server like the ones from J River Media, then the included graphic and parametric equalization options will allow you to further fine-tune your computer audio appreciably better than the aforementioned acoustic options alone. And using a sophisticated device like a Lyngdorf with RoomPerfect™ or the new Wavelet from Legacy Audio would provide additional flexibility in room control and fine tuning. If you manage to try one of these advanced devices I’m sure you’ll be amazed. End of rant! [Please note that the Lyngdorf DPA-1 has been discontinued but that Lyngdorf is still producing alternative models with RoomPerfect™.]

System Setup

Knowing a little about the design of the BHK 250—6922 tube input stage with a MOSFET output stage and weighty transformers and other high-quality parts under the hood, I expected good things. So after I put another 70 hours of playtime on the amp, I was ready to rock.

I had both the PS Audio DirectStream Memory Player (DMP), and the DirectStream DAC hooked up as well as the Lyngdorf DPA-1 pre-pro with analog and digital inputs plus advanced RoomPerfect™ room correction. And for those of you who may be thinking something like “wow, that’s not fair, he used room correction,” I will note that RoomPerfect™ only knocks down excessive, room induced peaks (very helpful in the bass) and corrects phase issues for improved imaging. And it also provides a “Bypass” button on the remote so I can hear the original unaltered presentation instantly for direct comparison. On several songs I enjoyed the pure sound of the bypass mode, but on most songs I thought the room correction helped a fair amount by maintaining and actually improving the layered imaging and the overall bass linearity in the listening positions. And since I had used the Lyngdorf DPA-1 previously with the Rogue ST-100 tube amp and the same Legacy Focus SE speakers, I was familiar with what it can do and what it does not do. For example, in my view it allows the listener to hear more of what the system electronics and speakers are doing by lessening the negative effects that the room acoustics cause. This is because calibrated microphone measurements are taken in the near field for each speaker and then compared to measurements taken in the listening positions and around the room. Filters are then derived from those measurements.

In addition to my digital sources, I had my modified Michell Orbe SE turntable installed in the same system using an all-tube phono stage from Aural Thrills Audio and a Wilson Benesch ACT 0.5 carbon tone arm with a Benz-Micro low-output Ebony L cartridge. It all worked very well for playing my cherished vinyl.

The Sound of “AWESOME”!!

So, to begin my serious listening, I put on a few familiar favorites beginning with Regina Spektor’s What We Saw From the Cheap Seats CD (Sire 530373-2). I must say that the BHK amplifier seemed to capture all the emotion and immediacy in Regina’s vocals throughout the album. Songs like “Don’t Leave Me,” and “Firewood” were particularly well served with great layering of the instruments within the vast soundstage, and “All the Rowboats” which is kind of amusing lyrically, exhibited some deep and impactful bass that could not be ignored.

Then moving on to Patricia Barber’s Companion CD, (Blue Note/Premonition 7243 5 22963 2 3) there was a wonderfully live sounding double bass on Track 2 “Use Me” that made the song pop. And on my favorite (Track 5) “Touch of Trash,” in addition to Barber’s sexy inflective vocal there were some powerful cymbal crashes, sharp clacking drumsticks, and I have to say that the audience sounds at the end of the song were very realistic and enveloped me as if I were attending this live concert. As you might have guessed, “Touch of Trash” is a very LIVE sounding track that effectively brought the concert into my audio room. Great stuff!

Another great album I used for reference was Sean Hayes’ Flowering Spade (Sean Hayes B0014SZDEU), which has a wealth of wonderful, well recorded songs on it. Playing Hayes’ song “Onion,” the horns sounded great and the brushed cymbals were about as airy and natural as I’ve ever heard them sound. I made a note that said “Inspiring sound—better than live??” so I know it impressed the heck out of me. And on “Sally Ann,” Sean’s vocal was spot-on and the plucked guitar strings couldn’t have sounded more authentic. I really enjoy this album!

It is also worth noting that with the BHK 250 amplifier I hear greater differences in recording quality between my various recordings. There are more gradations of quality and as a reviewer and music lover this is something I can truly appreciate.

Caveats

I confess I have no criticism of the BHK 250’s sonic performance—only high praise. It is extended and detailed at both frequency extremes and has an immediate, musical, and open sounding midrange (all qualities I love). That being said, at a hefty 83 pounds net weight, the amp is a bit difficult to move around. So I found a good spot for it and left it there. J

Conclusion

Although the PS Audio BHK Signature 250 stereo amplifier is higher priced than most amplifiers I have used, for an amplifier of this pedigree and obvious premium quality I believe it is quite the bargain at its current $7,499 price tag. In fact, I would seriously consider snapping one up while this price is still available.

It packs quite a wallop and is very powerful, what with its rated 250 watts/channel at 8 Ohms and 500 watts/channel into 4 Ohms. Of course one can always buy the monoblock versions for double the price and get a touch more headroom that way. Paul McGowan believes the monos sound a bit better, but based on my own experience I have to wonder how much better they could possibly sound!

So I think I will just buy this beastie and be thrilled with it! Very highly recommended!

 

I am always curious how a great piece of gear comes to be. Was it a singular vision of a talented engineer? Perhaps a group effort guided by an experienced team leader. In this case, it was indeed a visionary designer: Bascom H. King (hence the ‘BHK’ acronym). However, he had help in the form of a couple of long time industry veterans. Paul McGowan of PS Audio was looking to upgrade PS Audio’s amp and pre-amp offerings and was assisted in the effort by Arnie Nudell, of Infinity loudspeaker fame. Provided with an opportunity to create a signature set of electronics as a capstone to his illustrious career, Bascom King laboured alongside his long-time friends McGowan and Nudell and has succeeded brilliantly.

The BHK 250 stereo amplifier’s circuit design first appeared in 1979, when Bascom King created the HCA hybrid amp for Infinity. Harkening back to that original concept the BHK 250 has a tube input stage utilising a matched pair of Genalex Golden Lion 6922’s (a personal favorite of mine), allowing for no loss of musical information. The output uses only N-Channel MOSFETs to create a “near perfect balanced waveform without the degradation inherent in a complementary design” according to psaudio.com. Coming in at a hefty 38kg’s, the BHK 250 uses separate input and output power supplies keeping each part independent inside the single monolithic amplifier box design. PS Audio also offers the amp in monoblock form as the BHK 300. That version doubles the output current using only half of the impedance found in the BHK 250. Damping factor is also doubled in the mono amp, albeit at twice the price.

My first introduction to the BHK 250 was last year at Rocky Mountain Audio Fest in Denver. PS Audio’s room is always a must-hear treat, and the new amp was driving an imposing pair of YG Acoustics Sonja 1.3’s to great effect. The terrific musical presentation was made even more impressive when I found out the price of the amp was £8,000. This was very interesting as Bascom’s last collaboration was the creation of the extraordinary Constellation Audio Hercules amp, which costs more than ten times as much in its current version II guise! This more price aware approach was one of the design goals for the new PS Audio BHK lineup: to offer true world-class performance at a significant discount to the prodigious prices found in ultra high-end audio today. It took a few months but I was able to procure a BHK 250 for review along with the BHK Pre-amp. They would join my PS Audio DirectStream DSD DAC to join up with my Vandersteen Treo CT’s. Moving the BHK 250 onto its stand between the Treo CT’s I hooked up the AudioQuest CastleRock speaker cables and AudioQuest MacKenzie XLR interconnects. Burn-in time is recommended at 200 hours before critical listening should commence.

It’s a personal thing, but what I seek in an amplifier is ample power for the speakers being used with a solid grip on the low end. I would also like it to be as neutral as possible and allow the signal to pass through it as undisturbed as possible. In other words, I am not looking for it to add character. I do give extra consideration to a visceral sense of dimensionality, which is something I experienced early in my listening when I played ‘Take Five (Take another Five)’ from Grover Washington Jr’s SACD Prime Cuts [Sony Music], played on the Oppo 105D. This creative version of the jazz classic offered space and dimensionality. The depth of the soundstage was breathtaking. Spatial cues were present in abundance. In the centre of it all were the pure saxophone tones of the master, Grover Washington Jr. It was a clinic on musicality and a joy to experience. While I was enjoying the rest of the SACD, I came over all alpha-nerd and perused the parts list of the BHK 250. PRP Resistors matched up with film and foil Rel Caps all hand soldered through the circuit board without surface mount components. An approach found primarily on gear running well beyond £10,000. Sonic quality with sound (no pun intended) value. The BHK 250 was ticking many of my ‘need to have’ audio boxes.

Moving on to something more intimate I selected the SACD of Nick Drake, A Treasury [Universal – Island Records]. ‘River Man’ is a haunting guitar and strings melody with deceptively ‘simple’ chord changes. Once again, the character of the dimensionality of the presentation created an in-the-room sense. The violins’ tonality had that lovely blend of pure sound married with the physicality of bow on strings. Finger work on the guitar was sure and crisp. Drake’s vocals were centred as they should be, conveying his haunting fragility. This is where one really begins to appreciate the tube input and the capabilities of the 6922’s to preserve the sense of body and wholeness of the recording. In fact, I attribute these qualities not only to the valves chosen for the design, but also to King’s decision to use independent power supplies for the amp’s input and output stages.

Given that we have valves in the amp that means you can tube-roll to tailor your sound. Swapping tubes is very easy with the BHK 250. Simply loosen the two Philips head screws holding the back plate covering the tubes and replace the installed 6922’s with any 6 or 7 series dual triode variant. Make sure to follow the steps in the manual to avoid damage to the amp or the tubes. I had a matched pair of broken-in Tungsram PCC88’s that have been commented on favorably in the PS Audio forums on the manufacturer’s website. My experience with these tubes showed an increase in midrange focus and some extended treble beyond the Genalex 6922’s. After installing the Tungsram’s it was time to return to more listening.

I recently received a copy of Pink Floyd’s Dark Side of the Moon on 180-gram vinyl [Pink Floyd Records]. Placing it on my VPI Scout 1.1, with its Dynavector 10X5 cartridge, and ALO Audio phono stage, I sat down to enjoy an all-time great. First impressions were black as in zero background noise during the opening of ‘Breathe (In the Air)’. The clock and chimes came from nowhere to spread out across the room. The heartbeat reverberated from the front to the back of the room with solid force. Roger Waters’ bass notes were solid and deep, but well controlled. It was an exceptional delivery – one that led to my playing the entire record and letting out my inner hipster as I got up and turned over the record half way through. Actually, in my mind, vinyl never left: it has always been a great way to experience music. Paired with the BHK 250, I could enjoy the best of analogue in all its organic three-dimensional glory. The nuance of Dave Gilmour’s guitar work was on full display. It was the best I had ever experienced this long time classic.

Bascom King and PS Audio’s stated goal when designing the BHK 250 (and its brothers the BHK 300 Mono’s) was to create one of the top five amplifiers in the world and to spare no expense while doing it. Yet they also strove to make them much more affordable than the statement amps found throughout high-end audio. On the PS Audio website page for the BHK 250 and 300 amps under the “Want more product details” tab are nearly an hour and a half of video featuring Paul, Arnie, and – of course – Bascom describing in detail their goals and aspirations for the project. This extraordinary level of manufacturer transparency gives the prospective owner both a high level of understanding and confidence in the product they are purchasing. Bascom, Paul, and Arnie’s combined 150 years of audio excellence has led to a design of classic physical beauty and sonic excellence that easily achieves the goal of competing with über-level amplifiers, but at a fraction of the retail price. As audiophiles, we sometimes fall into the ‘price equals performance’ trap. We fear being the emperor with no clothes when our friends ask how much we paid and it was, gasp! LESS than what flagship gear is supposed to cost. Naturally it must not be that good. This amp is that that rare Holy Grail whose sensible price belies its astounding performance. Hand built in America, it may well be your final amplifier purchase.