Text and photos by Juan C. Ayllon
He couldn’t have summed it up better.
“What we hope for in any piece of hi-fi equipment is sonic transparency. We get there by practicing the Hippocratic oath, ‘First, do no harm’,” Paul McGowan, CEO of Boulder, Colorado-based PS Audio, writes Elaborating, he asserts that the manufacturers of high fidelity audio equipment should strive to “...leave as small a musically agreeable footprint as possible—to do no harm, and what little impact we have should be toe-tapping good.” (McGowan) Over the course of the last six months, I have concluded that Mr. McGowan has achieved this objective with his $6,000 reference level PS Audio BHK Signature Preamplifier, which is the most transparent active preamplifier I have employed in my listening space.
Active vs. Inactive
For several years, I used a passive preamplifier, which is essentially a potentiometer (volume knob) with several inputs and outputs. The reasoning was that the more you put in the signal path, the more distortion you get, versus with a good potentiometer, that’s not an issue: whatever is fed into it goes directly into the amplifier, as modulated by the volume control. The downside is that they dynamics can be a bit flat compared to active (powered) preamplifiers, which add gain to the signal before passing it onto the amplifier. Moreover, if there is an impedance mismatch, you may have to add an active buffer on the backside of the passive preamplifier, but that’s another matter. With an active preamplifier, you often get coloration; other things, good and bad can be added to the signal, as well. However, about a year and a half ago, I reviewed a very high performance preamplifier made by a speaker and amplification designer, Sam Wisniewski, based out of Poland and was stunned to find that it added very little in terms of coloration, save a little added warmth, and enhanced the dynamics and perception of detail. Since then, I have listened to several other active preamplifiers in my system -- one which lost a little detail, but added that classic and pleasant, warm vacuum tube sound, and this one, the PS Audio BHK Signature Preamplifier, which did not. I was in for a treat! Pedigreed Preamp Having co-founded PS Audio with Stan Warren in 1973, then left to join the late Arnie Nudell of Infiniti Systems to build speakers with Genesis Technologies in 1990, only to return in 1997 to resurrect PSA (which had gone under) to stellar heights as CEO and primary new product designer in 1997, Paul McGowan is no slouch. To create his reference level preamplifier, he enlisted the services of Bascom H. King, who in addition to designing some of PS Audio’s amps, has worked as a designer of hi-fi equipment with the likes of Conrad Johnson, Counterpoint, Constellation Audio, Infiniti and Marantz in a career that has spanned over 50 years. Thus, when King claims that “...this is the best sounding preamplifier I have ever designed or heard”, it bears taking notice. (“BHK Preamplifier” and Darko)
The Arrival
A substantial, 31 lb. box arrives and opening it, I find a pair of white fabric gloves along with the preamplifier, control unit and instructions. Somehow, I felt underdressed for the unpacking ceremony, but soldiered on. The 17” x 14” x 4”, 22 lb. chassis of the BHK Signature is an exercise in minimalist modern industrial design -- a spare, rectangular assembly of metal sides with rounded corners, a faceplate with the PS Audio sine wave logo at the upper left corner, a slender display window and volume knob to the right, and a shiny plexiglass top vented to the rear. A tiny power button and scarcely detectable headphone cable input are the left of the display window. It comes in either silver or black (the review sample they shipped me is black) and includes a sleek and slender aluminum and plastic remote control. There are five RCA inputs and five XLR balanced inputs and a pair, each, of RCA and XLR outputs on the rear. It boasts a “zero-loss” vacuum tube input stage with two 12AU7 dual triode vacuum tubes inside that may be swapped out for other tubes (“tube rolling”) with a switch that allows the user to use both 12 and six volt tubes. Other features include:
Power consumption is 60 Watts, minimum input impedance is 33k Ohms for RCA (unbalanced) inputs and 66k Ohms for XLR (balanced) inputs, while sensitivity is 1.3V/33 k Ohms for RCA (unbalanced) and 1.3V/66k Ohms for XLR (balanced). Output level is 4.0 Vrms, output impedance less than 100 Ohms, frequency response from 20 Hz to 20 kHz is +/- 0.1 dB, and THD&IM at 1KHz (full scale) is less than 0.03 percent. (Ibid)
A Hit with the Crowd
Roughly a week after the BHK Signature Preamplifier arrived, it played support duties to the VPI Prime Signature turntable when I hosted the Chicago Audio Society in late March. Both vinyl and digital files (as delivered by the Lampizator DSD Komputer and modified Lite 7 DAC) were immensely enjoyed by the 20-something members in attendance. Combined with the Odyssey Khartago Extreme SE amplifier, the Von Schweikert VR-5 HSE speakers, the BHK delivered a performance that had attendees buzzing afterwards. In the months that follow, I enjoy the performance of the BHK Signature preamp for numerous listening sessions, movie and TV viewing, and I employ it in a small handful of reviews. Coincidentally, after my wife and I purchase a Vizio 65 inch flat screen TV (linked to the Lampizator Lite 7 DAC via optical cable), I discover that the remote for the BHK Signature operates on the same frequency as the Vizio, causing some awkward moments when using my system as home theater (I find out later that a friend has the same issues with his Apple remote and his Vizio TV). Flipping forward through the Netflix menu has the disconcerting effect of raising the volume, which could result in seriously damaging ones speakers if you’re not paying attention. I found myself either repeatedly turning the volume knob down low as I scrolled or simply turning off the preamp until I’d found the movie I wanted to watch and turning it on afterwards. After months of enjoying the BHK Signature Preamplifier, I have to face the inevitable: it is time to give it a formal evaluation, which occurs over several sittings. Listening Sessions:
Daryl Hall and John Oates. “Sara Smile.” Rock ‘N Soul Part 1. Vinyl. 33 ⅓ RPM. RCA Records, October 18, 1983.
John Oates’ patented mournful, glowing, Fender Stratocaster arpeggio lead-in sounds just right. The keys, Scott Edwards’ bass, Jim Gordon’s drums, Daryl Hall’s patented, silky vocals sliding from vulnerable tenor to falsetto and back again, Oates’ velvet falsetto backgrounds and interspersed, harmonized leads are rendered warm, three dimensional and vivid. The subtle echo and/or vocal effects giving a sense of space, and the background strings are well articulated and warm. Sitting down to listen to this performance rendered on the VPI Prime Signature turntable with the Ortofon Black Quintet, it’s hard not to set aside my tablet and simply get lost in the music. For a mass produced pop record, it doesn’t sound bad at all.
Alan Parson Project. “Sirius” and “Eye in the Sky.” Eye in the Sky. Vinyl. 33 ⅓ RPM. Arista, June 1982.
The song, “Sirius,” long known as the Chicago Bulls’ entrance song sounds vivid, balanced and full, with the occasional small pop and hiss reminding you that this is a vinyl record. Then, as it fades to “Eye in the Sky,” Eric Woolfson’s lead vocals, along with David Paton, Chris Rainbow, Lenny Zakatek, Elmer Gantry and Colin Blunstone on background vocals are smooth, warm and engaging. As with the rest of the band -- Woolfson on keys, Paton’s electric guitar and Stuart Elliot on drums envelop me in a very pleasant sonic blanket.
Mark Anthony -- Remix by Eric Kupper. “I’ve Got You (Ibiza Club Remix).” I’ve Got You. Vinyl, 33 ⅓ RPM. Columbia 2002
Marc Anthony’s vocals, the acoustic guitar, synthesizers, precision bass, trumpets and Electronic Dance Music bass thump come comes through clear, luscious in its layering and well articulated in this old favorite vinyl single from my DJ’ing days (you can view it playing in the video I created below).
John McLaughlin. “Seven Sisters.” The Heart of Things: Live in Paris. AIF 44.1 kHz 16 bit. Verve Records, 3 October 2000.
The delivery is uncanny in its realism: McLaughlins electric guitar fades in with a lilting and airy arpeggio, accompanied by Dennis Chambers on ride cymbals in real space. Gary Thomas’ saxophone lead is well rounded and natural. followed by Jim Beard’s well articulated acoustic piano solo as the song builds to a frenzied back and forth between McLaughlin, Ever frenetic, McLaughlin rips into blinding fast riffs, with Chambers more than holding his own with crashing cymbals, double kick drums, snares and toms. Ditto for Thomas, whose saxophone skills are prodigiously on display. The sense of air, the timbre of the instruments, the tone -- it’s all there in spades. The crowd cheers -- as I do on the inside. This is why I love audio, I sigh. For moments like this.
Boyd, Rupert and Laura Metcalf. “Reflexoes No. 6 for Cello and Guitar.” Boyd Meets Girl. DSD128. Native DSD download. Sono Luminus. 28 July 2017.
The virtuosity of Laura Metcalf’s cello and Rupert Boyd’s classical guitar are wondrously conveyed in great acoustic detail. Although I am not a classic lover, I find their collaboration -- and especially Metcalf’s full bodied cello -- highly emotionally evocative. Her cello’s mournful, expressive and expansive range strikes a note in my heart, while Boyd’s acoustic guitar undergirds and supports her with understated elegance. The instruments ring true and the echo and delay in the background gives a real sense of the recording space they are in. With the BHK Signature, there is no smearing, smudging or syruppy affectation; it simply delivers the magic of the moment and gets out of the way.
Head Case
I listen to two more selections playing on the VPI Prime Signature Turntable via the Audeze LCD-3 headphones, which are connected to the PS Audio BHK Signature Preamplifier. Unlike another preamplifier with a built-in headphone amplifier, this one automatically adapted to the various impedances presented by different headhphones (these observations took place in a previous review of the Audeze LCD-3 and Sennheiser HD 800S headphones and the Audio Art HPX-1SE cables that you can read here)
Larry Carlton “The BP Blues “. Last Nite. Vinyl 33 ⅓ RPM. MCA Records, February 17, 1986.
The masterful live performance at the Baked Potato is captured in all its glory: the magic in Carlton’s soulful, expressive electric guitar lead and his dialog with longtime friend and collaborator, Terry Trotter, on keys, John Robinson keeping time on drums and Abraham Laboriel’s nuanced and muscular bass undergirding the band and, in a more quiet passage, plays with nuance as he swaps leads with Carlton. The trumpet solo by either Jerry Hey or Gary Grant (it doesn’t say which, but only that they comprise the trumpet section), comped by Laboriel and Trotter is scintillating. Then, as if to say, “You ain’t seen nothing yet,” Carlton comes back slowly, builds up to an intoxicating solo and, with the whole band in scorch mode, finishes with a flourish that leaves the crowd clapping and cheering.
Miles Davis. “So What.” Kind of Blue. Vinyl 33 ⅓ RPM. Columbia, August 17, 1959.
Winton Kelly’s piano lead in, followed by upright acoustic bassist Paul Chambers, and Billy Cobbs’ lilting drums cymbals, horns comping. Miles trumpet joins in. Wow. Magic. Add John Coltrane’s saxophone solo in its early, mathematical, frenetic rephrasing attack, followed by Julian “Cannonball” Adderley’s more melodic, rounder approach and you have a very special, intimate event. As delivered by the BHK SIgnature, it’s transfixing and haunting. The Sublime Truth The PS Audio BHK Signature Preamplifier has proven to be a very transparent and true conduit for the music to flow through. Having heard preamplifiers in my system, I can say with confidence that while adding dynamics and range to whatever signal is fed to it, the Signature is the most transparent and neutral of the active preamps, giving added life and expression, but otherwise stepping out of the way of the music. Bottom line, the PS Audio BHK Signature Preamplifier is the ultimate witness to the music: It tells the truth, the whole truth, and nothing but the truth! If you give it a bad recording or inferior sources, you will hear it. Garbage in, garbage out, as the computer dictum goes. However, if your source is good, you will hear it in all its glory. Remember that first active preamplifier that I mentioned earlier? I am scheduled to take receipt of that very same review sample in early August. Were it not for this fact, I would be very tempted to save, borrow or steal to get the PS Audio BHK Signature Preamplifier. It’s just that good. Software and Equipment Used:
Work Cited:
“BHK Preamplifier.” PSAudio.com. PS Audio 2018. Web 24 July 2018. Darko, John. “PS Audio Ready BHK Signature Pre-/Headphone Amplifier.” Darko.audio. 2016. Web 24 July 2018. McGowan, Paul. “When Transparency is the Goal.” 25 May, 2018. Paul’s Posts. PSAudio.com. PS Audio. Web 25 July 2018.
3 Comments
O_o scar Johnson
7/27/2018 12:38:05 pm
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Mitchell Erblich
3/6/2019 12:02:04 am
As an insane audiophile, I have 5+ audio / video systems, two of which have the Infinity IRS Beta speakers, one set being driven by VTL MB 450s and the other with Krell 250Ms, Carver Research Lightstar 1 amp. My reference pre is the Krell KRC-HR, that is a Class A amp with a separate power supply. Do you think that PS Audio could separate the power supply from the BHK Pre as an upgrade path for an audible upgrade. And what do you think the sonic benefits would be to then have the BHK pre Class A? Mitch E. BTW: I tend feed the analogue pre via one set of input XLRs from a external DAC., currently a Macintosh D150 on one system.
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3/6/2019 06:22:15 am
Hi Mitchell,
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