To paraphrase Spock of the USS Enterprise (at least the Spock of the UK comedy song ‘Star Trekkin’’ by The Firm), the Sony HAP-Z1ES is a network streamer, Jim, but not as we know it. It cannot stream data from Network Attached Storage. It’s not a USB or S/PDIF equipped DAC, so it cannot be used to play files straight from a PC or laptop. And it’s not a CD or SACD player, so you can’t slip in silver discs and play them directly.
So, what is it, and what can it do? It’s is a high-end music player, which stores music files on a one Terabyte internal hard disc and plays them from there. It can also stream music via a wired Ethernet, or its own built in WiFi.
The really nice thing about the Sony HAP-Z1ES is that it is also not a regular computer and so does not rely on flaky, quickly outdated, virus- and crash-prone operating systems. Of course, notionally at least anything from a CD player and beyond is a computer of sorts, and the HAP-Z1ES is no exception. It runs on a basic Linux core, however, rather than a full domestic operating system bent into shape. The result: there are a few good old-fashioned knobs to twiddle and press to select your music, as well as options from a menu. With a clear colour display to show what’s available and what’s playing. it could hardly be simpler. There’s a rather cheap plastic IR remote, but I never used it. I just downloaded Sony’s rather neat and easy to use HDD app, available for Android and iThings, and the interface became so easy quick and seamless that the remote was not necessary.
The only computer in the equation is the one used for ripping or downloading music files. Once the files are stored on a PC or laptop, they are ‘transferred’ as Sony describe, or more accurately copied, from the computer’s hard drive to the Sony’s. To enable transfers, all that’s required is to download an HAP app from the Sony website and connect both the computer and the HAP-Z1ES by Ethernet cables to a router.
So, how quick and easy was it to transfer? I had about 65 ripped CD’s and a few hi-res files on my laptop and these took the best part of the afternoon to transfer, on and off, (because the wired Ethernet link between the HAP-Z1ES and the computer dropped out a few times). It may seem like a long time, but it was quick compared to the two hours it took recently to download just one high resolution CD length 24/96 music file over the internet.
Apart from the unexplained pauses, the Sony unit handled it all smoothly, starting up from where it left off seamlessly, even checking with Gracenote and downloading its own cover art, (though if it gets the wrong image, it’s not clear how it may be corrected). If you add files to your computer, it will add them to the hard disc of the HAP-Z1ES to match. And, if 1TB is not enough, you can add a hard drive via a USB socket at the rear and the Sony will use that as if it were internal. It will reformat this drive to Ext4, destroying any stored data on the drive, but it allows for considerable expansion needs if you want.
This might seem a sideways step. The convenience of computer audio is that it’s, er, convenient. The files on your computer can be fed easily to a DAC and the files stored on a NAS can be fed to a streamer. Once the initial setting up is completed, everything is stable and seamless. The HAP-Z1ES doesn’t do this; it creates a point of isolation between computer and computer audio, which sounds counter-intuitive, but explicable. The idea has three distinct advantages. First is the overall amount of networking skills in the prospective buyer; locking the Z1ES into an existing Ethernet network in the home is potentially fraught with problems, because Drop-outs can be a problem in the home network isn’t built for robustness, especially if you are planning to listen to music at the same time as your eldest is blatting aliens online through his PS4. Then, there’s the potential for a lot of computer components behind the Z1ES to introduce RF and EM noise, there’s the emotional link that people make with their home devices, and how that differs from laptops, and finally there’s the ‘right tool for the job’ mindset that precludes using a multi-purpose computer for a dedicated task like music replay. If one or more of these ideas resonate with you, the Z1ES might offer a solution that’s not easy to come by elsewhere.
Back to the HAP-Z1ES. Much care and attention has been lavished on mechanical construction, as well as the electronics, which are based on Sony’s ES high-end hi fi and professional audio equipment. Inside, there are two large mains transformers, both vacuum impregnated for low vibration, which power separate supplies for the digital and analogue sections. It’s all mounted within a solid frame beam and base (FBB) chassis, (refined from the FB chassis in the R and ES series) by adding a vibration damping base comprising two metal sheets of different thickness to further minimise mechanical vibration.
It’s a theme carried through the construction, and applied even to the steel mounted rotary menu selector knob and its separate enter button. While the circuit boards are mounted firmly to the base, the analogue sockets are mounted separately to the rear, with flexible connecting wires to minimise vibration transfer from the outside world. The case is mounted on vibration-isolating feet. Not surprisingly, the HAP-Z1ES is a heavy piece of equipment, but the solidity, high quality build and external finish all certainly inspire confidence.
The signal processing and D/A conversion draw heavily on Sony’s experience with eight-times direct overs. (Let’s not forget, Sony was the joint inventor of CD and the inventor of the DSD digital recording and replay systems used for SACD, so they do know a thing or two about it!)
That is highly relevant to the HAP-Z1ES, because Sony has chosen to up sample ALL input data, regardless of origin, to 128xFs DSD data, which is twice the frequency of standard DSD (therefore, sometimes called double DSD). Sony makes use of a high performance Digital Signal Processor and FPGA (Field Programmable Gate Array) controlled by a crystal clock with very low phase noise (read into that low jitter), to convert the incoming data to DSD (as used for SACD). Of course, the neat thing about a DSD data stream is that it is basically an analogue signal which just needs filtering to remove the extreme levels of supersonic high-frequency noise which it contains.
In the HAP-Z1ES this filtering is carried out by a combination of four analogue FIR filters per channel (basically an analogue FIR comprises simply a sequence of delays which are added back into the signal, like a tapped delay line), and a gentle passive low pass analogue filter which, between them, attenuate the unwanted supersonic noise.
It’s rather like an up-sampling DAC, which shifts all the data and hence the anti-image filtering (and its associated phase shifts), to frequencies well above the audio range. However, as we are talking about a data rate of 5.6448 MHz for double DSD, this is a darned sight higher than even 192kHz DACs. The high frequency cannot replace information eliminated by transfer to CD, but it makes it easier to filter the ultrasonic noise of the DSD signal without affecting the audible range, minimising the potential for adding phase shifts, ringing, or early high-frequency roll off, (as can happen if the filter was set too close to the top end of the audio band). Sony claim an audio bandwidth of 2Hz-80kHz, for the HAP-Z1ES, which means the noise filter is set quite high, but to reproduce real audio information up to there would require 192kHz bit rate source material. Great for DSD fans, but if you are not one of them, this up-conversion can be switched off, as Sony have also included linear PCM D to A conversion as an alternative option available via the menu.
Added to Sony’s armoury is DSEE, (Digital Sound Enhancement Engine) which Sony has designed in an attempt to correct for losses introduced during compression (as with MP3, etc.). Hi-Fi+ readers may not be particularly interested with this feature, but, like DSD conversion, it can be switched in and out via the on-screen menu.
Of course, it is right to be sceptical about any extra digital processing, so I entered into this review with a little healthy caution. Would the HAP-Z1ES really deliver improved sound quality by up-converting to DSD as Sony claim?
Computer based audio once had more to do with convenience and less to do with quality. How things change! With 16bit 44.1kHz material ripped to mechanical, or, better still, solid state hard drives, (or to a mechanical drive and then buffered) before sending to a good DAC, it seems that some of the ills of the spinning silver disc can be overcome and sound quality elevated. Of course good higher resolution Linear PCM and DSD files betters standard CD resolution and sound quality. This is not a matter of opinion. Up till recently, DSD was the poor cousin, as it cannot be ripped easily, but now, DSD material can be purchased and stored, there is a growing band of enthusiasts who swear by it, while some may prefer hi res LPCM, and so the arguments for and against will, no doubt, go on.
Fortunately, this Sony player can satisfy all, and with files stored on the internal hard drive, the Sony has the potential to equal the quality of replay from a computer hard drive. Listening commenced by playing my plain vanilla CD rips transferred to the Sony. My initial (and continued) reaction was of disbelief that these files could sound so good. However, file after file and track after track played drove me to the same conclusions.
Even an old Frank Sinatra recording ‘Getting to be a Habit with Me’ from his Album ‘Songs for Swingin Lovers’ sounded fresh and new and quite remarkable for a 1956 analogue recording transferred to CD and then converted to DSD.
Old analogue recordings sound best to my ears, so it’s nice to hear them afresh even if they have been initially compromised by 16 bit 44.1kHz conversion to CD. For instance, while playing the Moderato from Rachmaninov’s Piano Concerto No 2 and the Allegro Ma Non Troppo from the Rachmaninov Piano Concerto No 3 (Conductor Antal Dorati), I noticed soloist Byron Janis’ grand piano had a solid well grounded sound, double basses were weighty, massed violins were silky and the horns rich and sonorous. This was a fully textured presentation in which the many parts were beautifully separated. The original analogue tape noise was audible but not accentuated and the whole piece had a delightful fluidity. This was not merely lovely sound, but a more insightful reproduction of the performance, something which draws one in and holds your attention. I think that is the great achievement of the Sony HAP-Z1ES, which helps to make it a true high end product at a bargain price.
Moving up in source quality to a 24 bit 192kHz file of Elton John’s ‘Yellow Brick Road’, ‘Funeral for a Friend’ (a Linn Records download). The powerful synth at the intro could sound glaring and over the top via conventional DACs. However, via the HAP-Z1ES and DSD up conversion, it sounded rich and mellifluous, while bass lines were solid and punchy. In ‘Come On Jamaica’ the tonal quality in the bass was clearly reproduced, with everything well separated despite the density of the mix. This was a big, lush sound with seemingly vanishingly low distortion – no sign of harshness or edge – translucent but certainly not glaring. Indeed, the sound reminded me more of an analogue master tape.
So, this DSD converted high res file sounded great, but more surprisingly, it was as though some kind of magic had been performed to make standard CD material sound less like CD and more like analogue, (or more like DSD, if you prefer!) Many divergent musical pieces were played and my notes refer again and again to the firm punchy (well timed) bass, rich creamy mid range and smooth, textured treble, and so on.
All these initial tests were carried out with the DSD transfer on, so I wondered how much of this magic was due to the DSD up conversion.
By turning the DSD on and off, it was quite clear that, although the standard LPCM digital to analogue conversion was very good, it was the DSD conversion which sounded more natural. DSD seemingly snapped instruments into focus and re-assembled the harmonics and fundamentals into a harmonious whole. For instance, connecting sibilants and fricatives in a more natural way to the underlying vocals – as though DSD re-aligned all the sonic parts more correctly in time, amplitude and frequency.
As just one example of many tracks tried, playing ‘Ain’t No Cure for Love’ and the ‘Song of Bernadette’ from Jennifer Warnes’ album ‘Famous Blue Raincoat’, the HAP-Z1ES with DSD revealed reverberation more clearly and Jennifer’s voice had a breathy rich, full and natural quality to it. With DSD switched off (to LPCM DAC) her voice was flatter, thinner and instruments had a scratchy sound more like the original CD.
In general, the DSD up conversion sounded softer (but more transparent!) And true DSD best of all. Listeners used to CD and its more incisive sound may prefer DSD off. In the end it is a matter of choice, but I believe critical listening will ultimately show the DSD conversion to be the more natural of the two – not simply the smoother or less bright – for this is far more than merely a tonal difference. Well, that is my view, others may or not agree and of course the switch is there for that reason.
I played various genuine DSD sample tracks, supplied with the player, such as Herbie Handcock’s ‘Water Mellon Man’, Miles Davis’ ‘Kind of Blue’, etc., and these did sound very fine indeed, as I expected.
But, for me, the really appealing and unexpected aspect of the HAP-Z1ES is not so much its ability to play pure DSD files, but the DSD up conversion. This means that I could listen at length to many more of my CD rips without being reminded of their origin. It is as though I have been given a new music collection. There were discs that had simply either been badly recorded or badly transferred to CD and these could not be rescued by the HAP-Z1ES. However, given a good original recording, and original digital transfer, the results could be amazing!. The few hi res files I have do sound even better, and I do want more of them, but many of my ripped CDs sounded so good that I am now enjoying plain vanilla CD, delivered in a new and enjoyable way. So, Sony’s claims have been vindicated. The results from up converted CD may not be true hi-res, or sound as good as true DSD, but they sound very nice, thank you!
I don’t normally listen to internet radio due to the poor quality of the low bit rate sources mostly available, but I did listen to some internet radio via the HAP-Z1ES. It sounded OK, maybe slightly improved by the ESS engine. It would not be my (or, I suspect, most Hi Fi + reader’s) first choice of musical entertainment, but it is there if wanted, and sounds better than most.
Rounding up, the HAP-Z1ES throws a curve ball on to the pitch, but may just turn out to be a game changer. At a price of £2000 it’s an audiophile bargain to boot. Though its not simply a DAC or a music server, if you are in the market for either, you owe it to yourself to audition it against the conventional alternatives.
My only disappointment is that I cannot rip my collection of SACDs on to my laptop for transferring onto the Sony’s hard drive, or rip discs of any kind directly to the Sony. I object to paying for SACDs again as downloads (and waiting hours for them to download via the internet). That is the big pity, but you can’t have everything!
Frequency response: 2Hz-80kHz
Dynamic range: 105dB or higher
THD: 0.0015% or less
Wired Lan: 1000BASE-T/100BASE-TX/10BASE-T
Wireless LAN: IEEE 802.11 b/g/n
*Some portions of the capacity are used for data management. Therefore the useable capacity is less than 1TB
Inputs and Outputs
Line Out (Unbalanced): Output 2VRMS (50kOhms)
Impedance: 10kOhms or higher
Line Out (Balanced): Output 2VRMS (50kOhms)
Impedance: 600 Ohms or higher
External port: USB type A, High-speed USB, for connecting an external hard drive
IR Remote Out (For connecting a mini plug cable (supplied) or IR blaster
Dimensions (WxHxD): 430x130x390mm
Manufactured by Sony