Pass XsPre – A Solid State Marvel

When Pass labs introduced the dual chassis Xs monoblocks a couple of years ago, they raised the bar for other components, and in the process even raised the bar for their own, already excellent XP30. We could end the review here by saying that on one level the difference between the XP30 and the XsPre is very much like the difference between the XA.8 series power amplifiers and the Xs monoblocks; everything is bigger, bolder, cleaner and quieter than what has come before.

Taking the financial aspect out of the equation, with the XsPre tipping the scale at $38,000 and the XP30 less than half of that at $16,500, the XsPre offers a lot more, if you have the room, system and software able to resolve the difference. For those that are familiar, think of the XP30 as a standard Porsche 911 and the XsPre as a fully geeked out GT3. You don’t need it to get the job done, but if it won’t affect your meal plan to acquire, you won’t be disappointed.

The AudioQuest NightHawk Headphones

Publisher’s Note: While I had a blast using the AudioQuest NightHawk headphones playing video games with my PS4, the team at AudioQuest did a lot of work on these wonderful headphones, so it only seemed proper that we put them through their paces as a “real headphone user” would.

So here is John Darko’s take on the NightHawk from that angle.

You can read more of John’s work here: We suggest you do so, he’s a clever chap.

But now, the review!

When AudioQuest asked exWestone engineer Skylar Gray to tackle their first headphone the design brief comprised only a single sentence: “Just make the best headphone you can make” . Implicit in this instruction was the new model would not be designed to a price. Early credit goes to Gray then for not going large and turning in a design that isn’t outrageously expensive by even today’s standards: a pair of NightHawk are yours for US$599.

Following the notion that ‘everything matters’, no stone was left unturned throughout the design process. Firstly, from a consumer point of view, there’s the ‘unboxing’ that isn’t. Gray pushed hard to have AudioQuest dispense with wasteful outer packaging. The NightHawk’s leather carry case is wrapped in a simple cardboard sleeve. Detach and unzip.

When first pulling the NightHawk from their case it’s obvious that these headphones are a break from the norm. Their semi-open backed design concedes diddly squat to contemporary aesthetic trends. Working from the ground up, Gray attended to how each and every facet of a headphone can influence its sound. The headband is made from stainless steel and wrapped in two layers of resonance damping rubber before a final layer of fabric is applied. The headpad, made of leather and microsuede, suspends a semicircular yoke that in turn attaches to the earcup’s 3Dprinted grille via silicone bands, a material that was stress tested to five years’ wear and tear before being chosen over the less costly Neoprene (a distant second).

Not only does this structural arrangement provide proper decoupling of ear cup from headband structure which can introduce unwanted resonances but it also has ergonomic advantages. If headphone comfort is of high priority, the NightHawk phones are up there with the best: they’re lightweight with only the mildest of lateral clamping force. The headband ensures that leaning forward doesn’t cause them to tumble off the head. If they do take a dive, these headphones’ seemingly fragile physicality could be their undoing; sans carrycase the NightHawks aren’t suited to bag life as well as other models (hello OPPO PM3).

Gray claims “a material with good acoustic properties” was required for the ear cups themselves. Kinda obvious, huh? Not so fast. The first casualty was a plastic that was not sustainable, leading Gray to test metal and wood. Viscoelastic rubber that turns sonic energy into heat wouldn’t sufficiently damp metal’s tendency to ring and wood didn’t pass muster due to its inherent inconsistencies, nor would it lend itself to being machined into complex shapes.  MDF failed to pass muster because the corners were too easily damaged.

Liquid wood sidesteps the subtractive manufacturing process required by the other materials and is sustainable. Win and win. Those who have seen the dashboard of a recent luxury car will be familiar with the highgloss burl is capable of. It’s also used to make lampstands and shoe heels. What you might not know about liquid wood is that it arrives at the factory as a pellet. Only when heated does it change to the liquid state required for injection moulding. The liquid wood pellets for the NightHawk are sourced from Germany and moulded in China, where final headphone assembly also takes place. The grilles are 3Dprinted in France, with the driver magnets and aluminum parts sourced from Japan, making the NightHawk a true multicultural product.

However, AudioQuest remains tightlipped about the source of the NightHawk’s driver material for which Gray refused to go with off the shelf materials. “It’s not in my or AudioQuest’s DNA,” he says. “The norm.” as Gray describes it “is a Mylar film that works well in small sizes but is constantly flexing and changing shape.” The latter reportedly causes low frequency distortion adding colouration above 3kHz. Gray calls this the “easy, cheap route”.

After dismantling numerous similarly priced rival models Gray, like all good designers, asked, “How can I do this better?”. Sony’s long gone but much vaunted MDRR10 headphones take the inspirational credit for the NightHawk’s biocellulose driver, a material made from bacteria feces reportedly costing twelve times that of your average dynamic driver to make. This material comes to life by feeding bacteria cultures carbohydrates, causing them to excrete a fiber, cultivated after several weeks, then dried and cleaned before being pressed into 50 micron thick sheets. The 42mm NightHawk driver diagphragms are cookie cut from the sheets. An 8mm driver surround keeps the drivers pistonic motion from distorting the shape.

With their roots in cables, AudioQuest supplies two with the NightHawk: a thinner cable with gold plated plugs, not designed by AudioQuest themselves but able to withstand the bending and winding of mobile use. A second, thicker, solid core, balanced cable with silverplated connectors that won’t withstand endless bending, but takes design elements from the company’s loudspeaker cables, featuring “Solid Perfect Surface Copper+ (PSC+) conductors in a Double Star Quad configuration” is intended for serious, furrowed brow home listening (as conducted here by yours truly).

I’m not going to tell you that from the first note I was immediately struck by a sense of blah blah blah . In fact, nothing from the NightHawk’s presentation really stands out: no rambunctiousness (KEF M500), no overt bass heaviness (Sennheiser HD650), no super incisive treble (Sennheiser HD800). In trying to assess the NightHawk’s personality, I learnt that there wasn’t one to be found. That’s good for the would be buyer but gives a reviewer very little to get his teeth into.

I advise a little persistence to those dismissing the NightHawk as boring or plain after all but a casual audition. Their quirk free presentation will take time to win you over. More excitement can be had from the Sennheiser HD650 phones, which in turn aren’t as refined. However, you can’t run the HD650 so easily from a smartphone…which brings me to the NightHawk’s real talent: they don’t need a lot of juicing to get going. An iPhone or an Astell&Kern AK Jr. will suffice.

The NightHawk’s lean towards finesse and delicacy (as opposed to overall heft and weight) means they don’t necessarily benefit from the additional tonal colour of tubes. Straight talking amps are the order of the day here: the Resonessence Labs Herus or further up the food chain the Chord Hugo. Heck, even AudioQuest’s own Dragonfly is a solid match and one that will have upgraders struggling to justify the additional expense of only minor superior performance wrought by better amplification. That the NightHawk offers an exit ramp from the hamster wheel of upgrades brings ‘em into everyman headfi territory.

Moreover, these are headphones for an oft neglected section of the market: owners of integrated amplifiers whose headphone sockets don’t do justice to the likes of tougher loads from MrSpeakers, Mad Dog, or Beyerdynamic’s T1. The AudioQuest’s 100db efficiency displays none of those rivals’ tendency toward stridency when underpowered. After all, the headphone output on your average integrated amplifier is designed more to complete a functionality checklist than drive specialist headphones; only low-impedance models need apply. Thankfully, the NightHawk come it at 25 Ohms nominal, making them a shoe-in with portables and dongle DACs.

The upshot? You can’t please all of the people all of the time, but with their NightHawk headphone, AudioQuest gets pretty darn close.

The AudioQuest NightHawk

MSRP:  $599

LONG TERM: The Robert Koda K-10 Preamplifier

Living with a hifi component for a long period of time is either a wonderful or dreadful thing. Features that seemed annoying at first can really be problematic after a time and magic that wasn’t always apparent at first really shines after about a thousand albums.

When you truly commit to a component, it’s almost like a long term relationship with a person; you either grow together or you grow apart. You need look no further than the recent court docket of divorce decrees or Audiogon to see who’s become tired of their spouse or their preamplifier.

Happily, after three years of using Robert Koda’s K-10 preamplifier, I still feel as if I’m on a honeymoon. After listening day in and day out, sometimes from sunrise to sunset and beyond, it remains one of, if not the finest preamplifiers I’ve had the privilege to own for a number of reasons.

The gold faceplate is reminiscent of Conrad-Johnson gear, but the one affixed to the K-10 is finished to a much higher standard. The only other gear I’ve seen with this level of quality in the machine work is Burmester. This extends to the control feel as well, there is a vault like solidity and security to using the K-10, and because it lacks a remote control, you will be using these fine controls regularly.

The understated aesthetics and lack of remote control may not be to the liking of those preferring more bling, but it will thrill the purist. Aesthetics aside, the sonic purist will be instantly transported as so many of my friends and acquaintences have been when listening to the K-10. This preamplifer does an incredible job of getting out of the way to just let you enjoy music. It doesn’t sound like a solid state or a tube preamplifier. It has no sound at all, and music merely unfolds, with an effortlessness that few components at any price can deliver in this manner. Acoustic instruments retain tone and timbre in a way that the right recordings will convince you that you are seated in front of the real thing and not a stereo system – if this is your idea of the absolute sound, look no further.


In my initial review of the K-10 (above), I said there was no limit as to how far you could peek into a recording with this preamplifier, and this has only gotten better with time. Now that I have listened to thousands of tracks through it, I continue to be amazed at the resolution, effortlessness and complete lack of sonic signature that it provides. Music simply unfolds from the K-10, and now that Mr. Koda has built a K-15 model, I can’t even imagine at how he could have improved upon this design. Maybe one will make it our way for a comparison someday? Every time I swap a different preamplifier in the place of the K-10, I find myself missing it, and that is the highest compliment I can pay any component.

As one who loves the physical look and feel of the K-10 as much as its sonic attributes, I put this preamplifier in the same league of classic creations like the Eames Lounge chair or a Porsche 911 – it is beautiful to listen to and beautiful to behold. Its subtle, understated elegance is something I never tire of and contributes a sense of peacefulness to my listening sessions.

However, the K-10 does have a few minor idiocyncracies that a potential owner does need to be aware of. The K-10s 6db of gain may not be enough for a few system configurations utilizing  low output moving coil phono cartridges or a modest gain phonostage,. With the high output of most DAC’s, (usually 4V) gain should never be a problem in an all digital system. When pushing the limits, I still would like a bit finer range of adjustment at the higher end of the volume scale, but again never enough to be annoyed.

For some, the lack of a remote will be an issue. Honestly, I thought it would drive me crazy, but forgoing the remote brings me back full circle to the beginning of my high end audio experience, when they did not exist! Let’s face it, most of us can use the exercise to get up and adjust the volume anyway! But most of all, the lack of a motorized or digital volume control makes for a quieter, more pure signal, I feel it forces you to focus more intently on the loudness level of the listening session instead of fidgeting with the volume control. Set it, relax and get into the music I say!

Three years later, the Robert Koda K-10 preamplifier still gets my vote for one of the world’s finest audio creations. I’m guessing three years from now I’ll still feel the same way. This one is a bit off the beaten path, but if you are looking for the ultimate audio Zen experience, in a preamplifier that makes a major statement by not making a statement, this is your final destination. Unless of course, you pony up for a K-15!

Issue 73


Old School:

Bang&Olufsen BeoCenter 9500

By Jeff Dorgay

The Audiophile Apartment:

Dynaudio XEO 4 Speakers

By Jeff Dorgay

Journeyman Audiophile:

Monk Audio Tube Phonostage

By Rob Johnson

995: Sounds That Won’t Break The Bank

Vanatoo Transparent One Speakers

By Jeff Dorgay

TONE Style

The Wino:
Cabernet 4 Ways
By Monique Meadows

Apple’s Latest Macbook

Doiy Bicycle Pizza Cutter



Spin the Black Circle: Reviews of New Pop/Rock and Country Albums
By Bob Gendron, Todd Martens, Chrissie Dickinson, Andrea Domanick and Aaron Cohen

Jazz & Blues: Dave Douglas, Robert Glasper Trio, Stephan Micus and More!
By Aaron Cohen and Jim Macnie

Audiophile Pressings: Introducing Intervention Records

Gear Previews

Fern and Roby Integrated Amplifier

Vandersteen VLR Speakers

Ruby STD Preamplifier

Thiel TM-3 Speakers

From the Web

Robert Koda K-10 Long Term Report

AudioQuest NightHawk Headphones

Pass XsPre Preamplifier


Audio Research GSPre Preamplifier
By Jeff Dorgay

ATC SCM40A Powered Speakers
By Mark Marcantonio

IsoTek EVO 3 Mosaic Genesis Power Conditioner
By Jeff Dorgay

Gryphon Kalliope DAC
By Jeff Dorgay

GamuT M250 Monoblock Amplifiers
By Jerold O’Brien