#BP17 | Explore Tumblr posts and blogs

taww · 7 years ago

Text

Review: PS Audio DirectStream Junior DAC

PS Audio DirectStream Junior DAC

The Audiophile Weekend Warrior (TAWW)

TAWW Rating: 4.5 / 5

Hugely resolving, relentlessly musical, highly versatile, sanely priced - my new reference.

PROS: Detail and naturalness in perfect harmony; highly upgradeable; versatile input and streaming options; nice looks and solid (American!) build.

CONS: Could be a tad cleaner and richer; some streaming and operational glitches; limited to DSD64/128; better suited to the technlogically-inclined.

If you're looking for a mega-review of this DAC, you've come to the right place. It's been a journey with the DirectStream Junior (DSJ for short). I received the review unit last summer, and first impressions were strong. Then some sonic gremlins reared their heads, and I was advised to hold for a software update, called Redcloud. That landed last December, and it’s been smooth sailing ever since - so much so, that the thought has never crossed my mind to use anything else. After several months of life with the DSJ, I can not only give it my wholehearted recommendation, I can also proclaim it my new reference DAC.

Highlights and Caveats

Some distinguishing features:

FPGA-based architecture (same as in the DirectStream) means it’s infinitely reprogrammable via software updates. This is a pretty big deal - see my Redcloud software notes for proof.

All input signals converted to 20x DSD, final conversion via differential bitstream (PWM)

Digital domain volume control (all input data preserved)

RCA and XLR (true balanced) analog outputs

Phase inversion and -20db attenuator

6 digital inputs (USB, coaxial, optical, AES-EBU, I2S, Ethernet) with automatic switching

Built-in Bridge II network interface (Ethernet)

MQA, Tidal Masters, Spotify, Qobuz, VTuner and Roon ready

Remote control

Designed and manufactured in Boulder, Colorado USA

Some caveats:

No Airplay support

Network streaming limited to 1x DSD (DSD64) and 24/192

No 4x DSD (DSD256)

MQA rendering only - requires initial decode (unfolding) in software (e.g. via Roon) Correction! The DSJ does indeed do full MQA unfold and render - no special software required.

Most of those buttons are for other things

Basically, if you want to play VERY high resolution formats (24/352 or 2x DSD), you’ll need to use a player connected via USB or I2S. And if want to natively decode DSD256 (4x), you’re out of luck - you’ll need to downsample it to 2x DSD. Given the relative paucity of such material, I don’t know how big a deal this is. And thankfully, MQA appears to be fully supported, if that's your thing...

DirectStream Junior vs. "Senior"

The DSJ retails for $4k, while the original DirectStream (I'll call it the "DS Sr." though that's not an official name) retails for $6k and the Bridge II network card is another $900. I consider the network interface to be an essential part of the DirectStream's utility and appeal (and it also sounds very, very good), so this basically makes the DSJ nearly $3k cheaper than the DS Sr.

So what are the key differences?

The analog output stage of the DS Sr. is passively-filtered via transformer coupling, while the DSJ uses high speed video op amps.

The DS Sr. has a larger power supply, 4x the circuitry around the output stage to reduce output noise by 6dB vs. the DSJ. The DSJ also uses less expensive parts in some locations.

As previously mentioned, the DSJ has a Bridge 2 network interface built in, a $900 option on the DS Sr.

The DS Sr. has an additional digital input (I2S) and uses an SD card slot (vs. USB port) for software upgrades. This just means you use a SD card on the Sr. and a USB memory stick on the Jr.

The DSJ has simpler casework and no touchscreen, but includes a control knob for volume and menu functions.

Some have said the DSJ has roughly 80% of the sound quality of the DS Sr. at a 42% discount. I haven't auditioned the Sr. in my system, so I can't comment on that... yet. I'm looking into getting one now, so stay tuned for that!

Setup & Tweaks

I used the DSJ 99% of the time via its Bridge II network input streaming a variety of 16/44, hi-res and lossy sources via Roon. The Roon implementation is fantastic - it's a fully certified device, and you get access to the input format capabilities and volume control settings in the Roon software. I also tried the standard S/PDIF inputs (with an Onkyo CD player and a Raspberry Pi with HiFiBerry Digi+ Pro board) and found them less sensitive to source quality than I’m accustomed to from typical DACs. No, it’s not “immune” to jitter - you can still hear the difference between transports and cables. But the differences are smaller than on, say, my Monarchy NM24 ladder DAC.

I only briefly played with the USB input, mostly to try 2x DSD material, and found it to also sound good. I used a MacBook Pro with DH Labs’s excellent Mirage USB cable ($200) and while it was subtly different than the Bridge II input playing the same material via Roon, I didn’t have a strong preference for one or the other. Overall the engineering seems uniformly solid and I didn’t find any obvious weak links with any of the input methods, a huge relief if you dread endless tweaking with digital cables and sources like I do. I’m not saying there isn’t some last degree of refinement to eke out but it’s probably not worth fussing over given that you can just plug and play and enjoy.

No shortage of inputs

One of my favorite features was the automatic input switching, which switches to whichever input has a signal. It worked flawlessly, and made quick A-B comparisons between sources a cinch. For instance, I could compare Roon playback via Bridge II streaming vs. a USB connection by simply alternating playback between the two in the Roon Remote app, and the DSJ took care of the rest. It also made it easy to hook up an AirPlay device and automatically play it whenever you stream to it. Very nifty.

Most listening was done using the balanced XLR outputs feeding my fully-balanced Ayre AX-7e integrated amp. I believe the unbalanced output is also derived from the differential signal (I saw a pair of instrumentation amps in the circuit, ostensibly to sum the balanced signal), and thus benefits from the differential DAC architecture. I detected no sonic compromises with XLR vs. RCA, it sounding just as good into single-ended gear like the Monarchy NM24 tube line stage or Bryston BP17 Cubed preamp. I've seen some very expensive gear that doesn't implement balanced circuits properly at all, but PS Audio gets an A+ for implementation here. I didn’t find the DSJ particularly sensitive to the type interconnect used; I settled on the Audience Au24 SX XLRs (review here), but also had good results with the much more affordable DH Labs Air Matrix.

While the built-in volume control makes forgoing a preamp possible, in practice it doesn't work well feeding an amplifier directly. The digital attenuation doesn't drop any bits - designer Ted Smith says it's computed by multiplying a 30-bit input signal by a 20-bit volume setting, and maintaining all 50 bits internally - but it's still done in the digital domain, which means the signal-to-noise ratio of the conversion process and analog stage degrades at lower volumes. When feeding the Bryston 4B Cubed amp, there was noticeable hiss even on the amp’s low gain (23dB) setting with relatively efficient speakers. This can be mitigated by using the DSJ's switchable 20dB attenuator, but I found it killed the life of the sound. Also the volume control software implementation is very jumpy and not particularly responsive to either fine or rapid adjustment. (PS Audio acknowledged this was due to some less-than-great control programming done by an earlier developer, and they're hoping to improve this in future releases.) In summary, leave the DSJ volume set to 100 with the attenuator disabled, and use a proper preamp or integrated amp for best results.

Somewhat unusual for a DAC, the DSJ runs hot. The chassis is fully sealed (I'm guessing this is likely for EMI/RFI compliance reasons as there's some serious computing going on inside). The top panel is a glossy black acrylic which looks very nice and helps dampen resonance - rapping it gives a dull thud vs. the metallic ding of most component tops - but it's also an insulator. This means anything metal gets pretty toasty, e.g. the RCA jacks. I do worry a bit about how this might affect component life... but Ted Smith says everything runs well within part ratings, and taking a peek under hood reveals lots of computer-grade, surface-mount parts that are designed for such operating conditions. Just give the DSJ plenty of ventilation - sealed cabinets are out.

ERS cloth helps clean things up that nth degree #crazyaudiophilestuff

There were two easy tweaks that I found helped tune the sound of the unit. The first was Cardas Myrtlewood blocks as footers. These gave the DSJ subtly tighter focus, more realistic tone and greater clarity vs. the stock rubber feet as well as other elastomer (Sorbothane) feet I tried. There was a very slight tradeoff in lower midrange body which may not be to everyone's tastes, but I found the tighter, slightly leaner sound of the Myrtlewood to be less wooly and more accurate, particularly with cello and baritone voice. The other tweak was ERS cloth, which you can buy from places like Music Direct. The late Bobby Palkovic introduced me to the material many moons ago, which allegedly blocks, absorbs and diffuses RFI energy, and I've always had a few pieces lying around my gear. People's reaction to the stuff range from hyperbolic ("it's miraculous!") to outraged ("total horse$%#!"). Call me crazy, but two small pieces (2" x 3", because that just what I have on hand) on top just above the analog circuits (near the RCA/XLR jacks) buffed out a tiny trace of hash and glare. It's subtle but takes the DSJ one step forward in naturalness and clarity. It's cheap enough to try, and I honestly wouldn't go back to using the DSJ without it.

By the way, this thing takes FOREVER to break in. I mean seriously, 500 hours in I still wasn’t sure the sound had settled down. Out of the box, it’ll sound a bit tizzy and lacking depth and focus. That will burn off fairly quickly, but it will take more hours for the tone and dynamics to fully develop and all the wonderful nuances in the music to blossom. I’d say give it a good month of continuous use - I logged nearly 1000 hours of playing time before I stopped worrying about it.

And then there's the choice of power cord...

Power cords galore

I found the DSJ to be fairly sensitive to the choice of power cord. For the vast majority of the audition, I used Audience's excellent powerChord SEi (USD $915/6 ft., review coming soon), and my comments largely reflect the sound with it. Towards the end, I swapped in a few other things:

Generic 14-3 cord: heavier than the usual 18-3 you see on most electronics but otherwise nothing special. (I don't think this is the one supplied by PS Audio, but looks pretty similar.) I was surprised that this cord made the DSJ sound a lot louder than the Audience - at matched levels, it sounded a good 1-2dB louder, no joke. The bass was stronger but muddier, with left hand licks on the piano lacking articulation. The soundstage also collapsed, making some recordings sound almost monaural - I actually checked that something hadn't gone haywire with my setup. The difference was pretty shocking, and while this cord didn't sound bad per se (some might even prefer it for e.g. rock music, which sounded harder hitting), it doesn't unlock the DSJ's full resolution potential. Overall I'd call it livable but non-optimal.

Pangea AC 14SE Mk II (USD $80/2m): I haven't been very fond of the Pangea in prior applications. With the DSJ, it was actually pretty good - like the stock cord, it sounded louder than the Audience, but restored much of the soundstage width missing with the stock cord. It's dynamic but a bit in your face, with some grain in the midrange and glare in the upper frequencies - I found violins a bit hard on the ears. Overall a decent budget option with the DSJ, particularly if you like a brasher, more energetic sound. Though not nearly as polished or harmonically complete as the Audience, electronic music drove a little harder.

Cardas Golden Reference (discontinued, around $500 back in the day): Frankly, I have never had good luck with this cord. In every application I've tried, it's sounded nondescript at best, constricted and veiled at worst. On the DSJ it gave a better showing, but had neither the energy of the less expensive cords nor the resolution and openness of the Audience. Its midrange and upper frequencies were closer to the Audience in smoothness, but it also tended to round the sharpness of transients - piano chords, snare drums and other percussion instruments sounded subtly muffled.

In summary, I think the stock cord is a reasonable place to start, but you can definitely get more out of the DSJ with something better. If you can afford the Audience, it brings out the most refinement of anything I've tried, but there are options with more slam. For under $100 the Pangea is a decent option, and Signal Cable makes a very nice affordable cable that by all accounts is a solid performer. I also have the new Audience Forté ($280) and an affordable model from DH Labs in house, as well as a very interesting DIY cable recommended by Marty DeWulf that is knocking my socks off... more on those in future installments.

Operational Kinks

The DirectStream Junior is a svelte, feature-rich package, and overall a pleasure to use. Over the course of several months use though, a few gremlins did rear their heads.

The software upgrade process can be hit or miss. In theory, all you need to do is download the files from PS Audio, unzip them, copy them to a USB flash drive, plug it into the USB port of the DSJ and start it up. However I have never been able to consistently upgrade the software EXCEPT by force-downgrading to a special older version (Yale with a different bootloader, available here), then repeating the upgrade with the desired newer software. Not all DSJs have this problem, but I've always needed the workaround.

Fully upgradeable software, but not without hiccups

The software can also become corrupted, a problem you won't have with a traditional hardware-based DAC. I have once had the unit become glitchy and not sound so good after losing power to the unit, e.g. by pulling the AC cord. This required me to repeat the software downgrade-upgrade process. Since then it's been more stable, but weird things can happen on power cycles, e.g. attenuator settings being toggled. It's important to follow PS Audio's recommendation of using the power switch on the back to power down the unit before unplugging it.

There are some pops and clicks when switching between PCM and DSD material. They're moderate in volume and Redcloud is much better in this respect than Huron, but it's still audible. More problematic is that DSD streamed via the Bridge II network interface will also suffer from intermittent pops. This is apparently a software issue with the Bridge itself that PS Audio is asking their vendor to fix - fortunately that's also easily upgradable, but there's no ETA yet on a patch. In the meantime, I haven't found the noise so distracting as to make it unplayable - it's almost like hearing a little surface noise on an LP - and the USB interface doesn't suffer from this problem. PCM signals including 24/192, are all fine.

It's important to remember the DSJ is a piece of sophisticated computer equipment running software. It's not hardcoded like a traditional electronics, and its flexibility does require a bit more technological savvy from the user. If you're computer-phobic, there may be a learning curve to maintain and get the best from the DSJ.

Okay, so how does it sound??

In short, if I were stuck on an island with one DAC, I could very happily live out my days with the DirectStream Junior. It's that good and that satisfying. Once it’s running Redcloud, fully broken in and dialed in with them aforementioned tweaks, the DSJ sings like no other DAC I’ve used.

All my notes refer to the DSJ with the latest Redcloud software. You can find my earlier impressions here:

It’s here! The PS Audio DirectStream Junior DAC

PS Audio Redcloud OS for DirectStream Junior DAC

For comparison, my previous reference is a Monarchy NM24 tube DAC with upgraded output caps and I/V resistors and solid state output stage disconnected. It’s based on the venerable Burr-Brown PCM1704K 24-bit ladder DAC, and while I wouldn’t call it state-of-the-art, it’s still one of the more musical DACs around and has easily outperformed units many times its cost.

Coming from the Monarchy, the first thing I noticed was the striking level of detail. It brings out all kinds of subtleties in a performance - the tap of a pianist’s fingernails on the keys, the bow changes on a violin, the resonance of a cello, the breaths of an oboist in a symphony orchestra, the variations in a soprano's vibrato layered perfectly into the presentation. This resolution is coupled to an ease of delivery that’s uncannily natural - there’s no artificial brightness, no in-your-face forwardness, no technicolor hyping of detail going on here. It's totally unforced, addictive and engrossing. This is what high-end audio is about!

The resolving power of the DSJ extends from top to bottom. In the highest reaches of the treble, percussion like cymbals and triangles sound highly realistic. Just put on Dvorak's Slavonic Dance Op. 46 No. 3 (Szell/Cleveland Orchestra/Sony DSD) and hear how perfectly the triangle shimmers and floats above the orchestra, its ring carrying on and on like you'd hear in the concert hall. In the lower midrange, instruments like cello and piano have layers of tonal color and texture that lend a lifelike presence. With timpani, you can clearly hear the body, skin and pitch of the instrument, not just a dull thud.

This detail also contributes to insanely palpable imaging. Every instrument on the stage has clear size, shape, and space around it, and you get a real sense of distinct sources of acoustic energy on the stage, each one exciting the surrounding air in its unique way - violin sections glowing across a swath of stage, oboes singing sweetly in center, bassoons honking away behind them, a horn melody blooming in the back. I've never been able to pick out and feel all the instruments in a symphony orchestra so tangibly like this.

Okay, just two more aspects of the resolution before I move on: firstly, it starkly reveals differences in recording techniques, technologies and qualities. Recordings truly sound distinct from one another, much more so than with other DACs, and you can hear all the idiosyncrasies of analog vs. digital, PCM vs. DSD, hall vs. studio, mic placement, etc. Secondly, this resolution is more than sufficient to challenge the capabilities of very high end systems. I found with every tweak to my systems, I uncovered more and more of the DSJ's capabilities, while otherwise excellent gear like the Bryston BP17 + 4B cubed combo masked its full performance envelope slightly.

The other remarkable thing is how consistently excellent sources sound regardless of resolution. Yes, DSD material followed by 24/192 or 24/96 generally sound best - just listen to a stunningly realistic modern album like Julia Fischer and Martin Helmchen performing Schubert works for violin and piano (Pentatone DSD), or a colorful remastered classic like Piatigorsky performing Walton Cello Concerto (RCA Living Stereo DSD) and you’ll be giddy with the sheer vividness of presentation. But things don’t drop off a cliff when you fall back to menial 16/44; on the contrary, this is some of the finest Redbook reproduction I’ve heard, with all the same loveliness of tone and fluidity of presentation as hi-res, just with a hair less resolution and palpability. Case in point, my wife was listening to a recording of Hindemith's Der Schwanendreher (Tidal 16/44) that sounded nearly as smooth and lush as any SACD I've heard - and much to my surprise, it was a DDD recording from 1989, an era I usually find pretty icky. And "sorta hi-res" 24/48 tracks got me pretty excited, e.g. Alisa Weilerstein's performance of the Elgar Cello Concerto (Decca/HDTracks) was rich, gripping and engaging. Heck, even MP3s sound pretty good - I once got sucked into the beauty of Maria Callas singing a Puccini aria, only to realize afterwards that it was a 160kbps MP3 from my iTunes library. The DSJ destroys the notion that higher fidelity has to come at the cost of intolerance to recording quality.

Tonally, I found the DSJ to be very even. The only thing I might watch out for is that the treble is so extended and open that it may strike some as a hair bright, but I found it natural and realistic in my system. The midrange has just a smidge of warmth to it, less so than the tubed Monarchy but with a pleasing roundness and harmonic completeness - you get a sense of body to instruments and voices that’s highly suggestive of the real thing. Where the Monarchy pulls ahead a bit is in the richness of the lower midrange and upper bass - it has more overt weight and boldness that gives everything more juiciness and presence. Going down low, I'd also call the DSJ's bass pretty neutral, with great pitch and appropriate weight to give the music a solid foundation, but perhaps lacking the subterranean thunder of the best I've heard (some of the old MSB multi-bit DACs come to mind). Perhaps this is an area where the beefier power supply of the DS Sr. could yield improvement.

What’s the catch?

The DSJ isn't the quietest and cleanest DAC I’ve ever heard - as noted, the noise floor is a little high, and there's sometimes a tiny trace of fuzz layered over the midrange that diffuses tones slightly. It can't match the eery quiet and purity of the Chord DAVE (granted at a price of $10k), and the multi-bit and tubed Monarchy has a more grainless density to instruments like the violin. While the Redcloud update fixed the most egregious noise problems, I think the upgrade to the full DirectStream, with a substantial 6dB reduction of noise floor, would be worthwhile for very high-resolution systems - I'm talking stuff in Pass/Ayre/Magico territory. The Chord DAVE also strikes me as having a superior analog output stage, as evidenced by its deeper, more tuneful bass, richer dynamics and overall purity - all expected for more than double the money. None of these shortcomings detracted from my enjoyment of the music, but listen closely enough against first-class competition and you'll find some areas for that last 10% of improvement.

I've heard some people say the bitstream conversion of the DSJ gives it softer, rounder transients compared to very resolving multi-bit DACs. I think this is a fair assessment, but I didn't find this to be an issue for me - in fact, I thought dynamics were excellent on the DSJ. It had plenty of bite when called for, presenting clean leading edges without harshness or overshoot. More importantly, subtle dynamic shadings - swells in a voice, variations in bow pressure, interplays between instruments - were wonderfully expressive. The Monarchy DAC sounded a bit flat and lacking color in comparison.

That said, I do feel that good multi-bit DACs have a suddenness, directness and dynamic linearity to them that differs from the bitstream DSJ’s portrayal. If I had to generalize, I’d say the DSJ is better suited to ears that prefer a more relaxed presentation, and/or a system that leans towards the incisive side to compensate. It won’t give you the larger-than-life boldness of a NOS tube DAC, nor the bracing presence of some of the Sabre-based units. It was a great match for the speed and alacrity of the Ayre integrated; with the darker, more subdued Bryston combo, I could have used more verve. Whether this works for you is probably more a matter of personal preference and system matching than absolute correctness; for me, the virtues of the DSJ’s natural, musically consonant presentation outweighed any tradeoffs.

Verdict

Back when I was in music school, I remember hanging out in our concert hall's recording studio while my friends were performing, and being struck by how much more vivid the live mic feed sounded than the recorded version (either on analog cassette or DAT). The DSJ is still bound by the limitations of recording technology, but it gives me more of that live feed feel than anything I've experienced in my living room. It doesn't have the distinct colorations of an LP, nor can I say it sounds like reel-to-reel tape (I don't have that at my disposal), but it removes so much of the digital glaze and glare we've grown accustomed to that it feels distinctly analog-like in nature. It has soul, it has tone and tunefulness, and you can listen to it for hours on end with myriad recordings and suffer no fatigue whatsoever.

No, I haven't heard a ton of the fashionable DACs out there like the TOTALDAC, Merging, Schiit Yggdrasil, Mytec, etc. etc. However I've spent some quality time with highly-regarded models from Aurender, Ayre, Chord and dcs, and I can't say they've offered me musical satisfaction that the PS Audio can't match or exceed. And the price of the DSJ, while expensive at $4k, is a bargain for the sound quality, feature content and build quality. PS Audio has a very liberal trade-in policy that can knock up to $1k off that price too.

Ultimately it's not all the audiophile mumbo jumbo that makes the DSJ special. It's how fluidly, vividly and convincingly it carries a tune and draws you into the performance, the way it captures the range of tonal colors, the beauty of voices and instruments, the energy and life in the recorded event. It's a cliché, but it took my system and musical enjoyment to new heights. It's my new reference, and not leaving my system anytime soon... at least not until the big brother DirectStream arrives. Enthusiastically recommended.

PS Audio DirectStream Junior DAC USD $3,999

PS Audio 4826 Sterling Drive Boulder, Colorado 80301

#review #digital #dac #ps audio #directstream

1 note · View note