Barry: Hey John – I read your piece on Building a Bridge with Bluetooth. Gee, your memory is good: my wife Sharon was indeed extremely upset that she couldn’t get TV sound working whilst I was away on business. I’d stupidly forgotten to show her how to change inputs on the Devialet Expert 200. What made matters worse is that I’d disabled the analogue outputs on the TV via its settings. Not my finest hour in the world of domestic harmony.
John: We’ve all been there, mate.
B: Sharon also wanted to know why ‘my’ stereo didn’t function as easily as ‘her’ UE Boom. I think I might have muttered something about Bluetooth getting found out in a high-end audio system. She didn’t buy it; if ‘we’ were going to have “all those boxes” (her words) in the lounge room then she wanted in on the action with her music.
J: Why don’t you hook up your Apple Airport Express and have her stream Spotify over Airplay?
B: She has an Android phone now and it doesn’t do Airplay. Besides, Sharon uses Bluetooth to play music via a UE Boom and then in the car for music and hands free calls. The point is, she knows Bluetooth inside out already. But…stupid me, I said no to a Bluetooth adaptor for the Devialet so she vetoed my purchase of a Wyred 4 Sound Remedy, which you’ll recall I was really into after hearing it at your place – wow, that must be almost two years ago now?
J: Yeah – August 2014. The Remedy really is a great unit, isn’t it? S/PDIF re-clockers aren’t too common and you heard first hand how it dialled down the audibly tense, nervous presentation of the Airport Express’ digital output. I’ve since heard what it can do for the Sonos Connect whose S/PDIF outputs sound as though they are also riddled with jitter.
B: I have a Connect! It’s great – the streaming service integration is off the charts in terms of comprehensiveness (and it just works) – but to me it sounds no better than the Airport Express.
J: I’d agree with that assessment. And this is precisely why you wanted the Wyred 4 Sound unit, isn’t it? To remedy the high jitter signals that spill from the Sonos Connect and Airport Express before they reach your DAC.
J: How about a brief re-cap of our Remedy discourse: hooked up to digitally intervene between Sonos Connect and DAC, the Remedy buffers the Connect’s digital output, re-clocks it (to 96kHz) with via an internal Femto oscillator and sends it on its way via Toslink or coaxial. In fact, Wyred 4 Sound CEO EJ Sarmento says that the Remedy is an external distillation of the digital modifications previously applied by his company to the Sonos Connect.
J: Yes – but the benefit of the Remedy is its potential to improve the digital output of any S/PDIF output, including cheap-ass Blu-Ray players and/or the Google Chromecast Audio.
B: You’ve just touched on something else that Sharon is down with: silver discs. The Sonos however she does not do.
J: She’s not the only one – but for different reasons. For many audiophiles, Sonos’ refusal to embrace hi-res audio keeps them from purchasing a Connect. That gives the AURALiC Aries Mini the edge in the entry-level hi-res streamer space. And guess what? The Remedy improves further on the Aries Mini’s already good-quality digital outputs.
B: Yeah, well, all of that’s academic ‘round here. Sharon said no the Remedy. We have a joint bank account so I can’t even buy one, smuggle it into the house and pretend it’s been there all along.
J: I think I might have a solution for your domestic impasse, Barry.
B: Go on…
J. I’m talking about Wyred 4 Sound’s new unit for 2016: the bLINK.
J: Imagine the US$399 Remedy shorn of its Toslink input, replaced by a screw-on antenna that handles aptX Bluetooth reception, and with US$100 added to its price tag. And like the Remedy, the bLINK buffers the incoming signal, re-clocks it with a Femto oscillator (tuned to 96kHZ) and outputs over Toslink or coaxial.
The coaxial input remains in place. So too does build quality solidity. Like the Remedy, the bLINK feels weighty in the hand. That outer shell is aluminium, hence the aerial. Oh – the bLINK is Made in Atascadero, CA – tour the W4S factory here – and comes with a 5-year warranty. Talk about faith in the future.
B: Very, very interesting. So I could re-clock my Sonos Connect and/or Blu-Ray Player whilst simultaneously offering Bluetooth access to the Expert 200?
J: You got it. A flip of the bLINK’s source selector switch is all it takes to move the input from coaxial to Bluetooth. The ‘Push to Pair’ button does exactly what it says: it sets the bLINK up for device pairing. bLINK = Bluetooth Link. Geddit?
B: Got it. Is the re-clocking circuit found inside the bLINK in any way different to that inside the Remedy?
J: I asked EJ Sarmento this very question. His reply: both circuits are identical. This is confirmed by my listening sessions: the bLINK brings the same degree of easefulness to the AURALiC Aries Mini as the Remedy. What you don’t get with the bLINK is a Toslink input; it cannot intercede between Airport Express and DAC.
B: Like I said, Sharon has a Samsung Galaxy smartphone now so Airplay is a no go. She wants Bluetooth, presumably because the connectivity process is familiar to her. And it sounds like the bLINK might be just the ticket. But level with me, Bluetooth doesn’t sound all that good, does it?
J: This is where our story gets interesting. Not all Bluetooth receivers are born equal. The Wyred 4 Sound’s Bluetooth signal is reclocked before output to the DAC. It sounds markedly better than the Bluetooth stream spilling from AURALiC’s Aries Mini. More fluid in the midrange and less metallicised in the treble. It’s what we might call Next Level Bluetooth.
B: It’s still lossy though, right?
J: Yes – and this is where things get geeky – but stream to the bLINK via an aptX compatible device, like a Macbook or Mac Mini, and the resulting sound quality shortfall compared to a direct USB narrows considerably. In the absence of an aptX transmitter, the connection reverts to the lower bitrate standard Bluetooth (SBC). aptX developer CSR maintains a list of compatible devices here.
B: Can aptX stream in CD quality?
J: Almost. Software developer CSR offers this explanation on aptX’s introductory page.
“aptX® audio technology delivers CD-like quality audio over a Bluetooth® connection. In order to fit within the Bluetooth ‘pipe’ and transmit wirelessly, audio needs to use a bit rate reduction technique. It replicates the entire frequency of the audio, reproducing pure sound and ensuring that users hear everything as the artist intended.”
Notice the devilish use of “CD-like”. SBC uses compression techniques similar to that of MP3 or AAC but aptX uses “time domain ADPCM” (click here if you dare). That’s according to this Bluetooth audio primer from Cnet.
B: Blimey – aptX Bluetooth is quite the technical minefield!
J: Want more?
From this Microsoft Support article:
“ADPCM, commonly termed as a form of compression, is a more efficient way of storing waveforms than 16-bit or 8-bit PCM. It only uses 4 bits per sample, taking up a quarter of the disk space of 16-bit PCM. However, the sound quality is inferior. Because the Windows Sound System hardware only understands 8/16-bit PCM, the computer must compress and decompress the ADPCM into/from PCM, which requires CPU time. 22 kHz mono ADPCM can be decompressed real-time (that is, while playing) on a 386SX/16 megahertz CPU. Higher sampling rates (44 kHz) or stereo files will take too long for a 386SX/16 to decompress, which causes skipping in the audio. 11 kHz mono ADPCM can be compressed real-time on a 386SX/16 computer. To do ADPCM, the computer must have the Audio Compression Manager (ACM) installed.”
“ADPCM stores the value differences between two adjacent PCM samples and makes some assumptions that allow data reduction. Because of these assumptions, low frequencies are properly reproduced, but any high frequencies tend to get distorted. The distortion is easily audible in 11 kHz ADPCM files, but becomes more difficult to discern with higher sampling rates, and is virtually impossible to recognize with 44 kHz ADPCM files.”
ADPCM – and therefore aptX – uses fewer bits per sample in implementing its data compression.
B: My head hurts. I need a lie down.
J: OK OK. I’ll stop. One key takeaway is that aptX won’t mangle the sound of an already lossy audio. Stream an MP3, Ogg Vorbis or AAC file from Macbook to bLINK and it sounds very, very good indeed.
B: Ogg what?
J: Ogg Vorbis. It’s the lossy compression codec used by Spotify. Apple Music use AAC.
B: What about hi-res audio? Not that Sharon would do it but could one stream a hi-res file to the bLINK?
J: Yes. aptX Lossless (which, it transpires, isn’t 100% lossless) offers support for hi-res audio. From Wikipedia:
“aptX Lossless supports high-definition audio up to 96 kHz sampling rates and sample resolutions up to 24 bits. The codec optionally permits a “hybrid” coding scheme for applications where average and/or peak compressed data rates must be capped at a constrained level. This involves the dynamic application of a form of “near lossless” coding – but only for those short sections of audio where completely lossless coding cannot respect the bandwidth constraints. Even for those short periods while the “near lossless” coding is active, high-definition audio quality is maintained, retaining audio frequencies up to 20 kHz and a dynamic range of at least 120 dB.”
B: Surely picking nits over the percentage loss is somewhat pointless. Hi-rezzers will use hard-wired connections, won’t they? I know I would.
J: I would think so, yes. And that’s what the bLINK’s coaxial input is for.
B: In your earlier post about Bluetooth’s relevance to high-end audio you likened it to the cassette tape?
J: Yes, more so in terms of breadth of application, less so in terms of sound quality. Bluetooth is to lossless digital audio what cassette tape was to the vinyl LP – a very useful and highly convenient transport mechanism whose sound quality was highly dependent on one’s hardware choices.
B: That takes me back. I used to own a Nakamichi Dragon. That thing was incredible tape deck – a noticeable upgrade from the entry-level Sony that it replaced.
J: Right! And your experience with those two very different sounding tape decks is analogous to our Bluetooth discussion here. Not all Bluetooth receivers sound the same. The Wyred 4 Sound bLINK reminds us that we get what we pay for. We could say that the bLINK is the Nakamichi Dragon of the Bluetooth receiver world.
B: So an audiophile like me would appreciate the bLINK’s sound quality, even over Bluetooth?
J: Yes, especially if your smartphone is aptX-enabled.
B: I’m currently using an iPhone 6.
J: Oh. iPhones don’t yet do aptX Bluetooth, only SBC. But Sharon has a Samsung Galaxy, right?
B: She sure does.
J: THAT does aptX! Besides – this isn’t about you or me, Barry. When my mates stop by – mates who aren’t what I would call audiophiles – they can play tunes from their smartphones on my high-end audio gear and without the minor hassle of wifi authentication. So taken are they by hearing their music on better loudspeakers, amplifiers and DACs that they care not about Bluetooth’s lossy limitations, especially when an aptX-equipped Android phone is the source.
B: So I should just stick to the Apple Airport Express with my iPhone?
J: Maybe. Maybe not. bLINK-d Bluetooth with aptX auto-engaged sounds as good the unaided Apple brick running Airplay. In fact, in terms of midrange fluidity, the bLINK gives us a better result. Lowering jitter seems to matter more than any bits thrown away by Bluetooth transmission.
B: Okay. That’s with Spotify, right?
J: Spotify and Tidal Hifi. But don’t lose focus: you want the bLINK for its S/PDIF re-clocking and the Bluetooth functionality is to help you get the purchase across the line with your wife, is it not?
B: Yes, you’re right.
J: That doesn’t mean you or other audio nerds won’t find the bLINK’s Bluetooth input extremely useful.
Firstly, one not so obvious benefit for Devialet Phantom owners is how the bLINK returns Bluetooth functionality to a stereo-paired Phantom system, surrendered when adding Devialet’s Dialog router. Connect the bLINK to the Dialog via Toslink and you’re off to the races. Know that this is strictly a functional upgrade. The air gap between Phantoms and Dialog renders the system impervious to changes in jitter levels entering the Dialog via its optical input.
For a lift in SQ and functionality we turn to those times when I’m sat on the couch with Macbook Air in lap. It’s a situation in which I often skip out on watching Facebook videos because I cannot abide the sound of laptop speakers. With the bLINK in the system, its coaxial output running into the Mytek Brooklyn, I can easily divert the Macbook Air’s audio output to the main rig which currently sees KEF LS50 loudspeakers powered by a pair of Red Dragon S500 monoblocks.
My only caveat with respect to the DSP-heavy Devialet Expert 200 – the exception and very much not the rule – is that it tends to homogenise digital inputs a little more than the Mytek / Red Dragon combo. We hear less of the bLINK’s liquidity. The PS Audio DirectStream Junior returns results from the bLINK that are closer to that of the Brooklyn.
B: I was already sold on the bLINK’s S/PDIF reclocking but I suspect Sharon would dig the Bluetooth input immensely.
J: What we have in the US$499 bLINK is Remedy-grade S/PDIF reclocking (for audiophile geeks) and that same reclocking circuitry applied to Bluetooth with quite outstanding results. That in turn spells high quality inclusivity for anyone sharing their home with an audiophile.
B: Wyred 4 Sound’s bLINK offers Bluetooth audio for everyone from your Mum to high-end connoisseurs with S/PDIF reclocking thrown in for those who prefer their streaming audio strictly hard-wired?
J: In other words, everyone wins.
Further information: Wyred 4 Sound