Arcam rBlink Bluetooth D/A processor JA on Sound Quality

Sidebar 1: JA on Sound Quality

Sam Tellig loved the rBlink when he listened to it: "If you're looking for a gift idea, and Mom and Dad have Bluetooth devices, put an Arcam rBlink under the tree. While you're at it, get another for yourself," he wrote. "Highly recommended," he concluded.

I streamed Bluetooth data to the rBlink from my iPad 2 and MacBook Pro. I did some listening to the rBlink's analog outputs. The sound was good rather than great, so for my primary auditioning sessions, the Arcam's coaxial digital output was connected to the ASUS Xonar Essence One Muses Edition (see review elsewhere in this issue); I also connected my MacBook Pro's TosLink digital output to the Xonar DAC so that I could compare the Bluetooth versions of the files with the original sent at full resolution to the same DAC via S/PDIF. I connected the Xonar's balanced outputs to the inputs of my HeadRoom BlockHead amplifier, which drove a pair of Audeze LCD-X headphones in balanced mode.

I began my critical listening with Vaughan Williams's Norfolk Rhapsody No.1, performed by Bryden Thomson conducting the LSO (ALAC file ripped from CD, Musical Heritage Society MHS 512595), streamed from my iPad via Bluetooth to the rBlink. The sound was surprisingly enjoyable when the music remained at moderate levels, though the sense of space on this ambient Chandos recording was diminished compared with the same file sent from my MacBook Pro via TosLink to the Xonar DAC. However, there was a feeling of congestion at orchestral climaxes, accompanied by a coarsening of the treble.

Streamed from the iPad, George Benson's cover of "Nature Boy" (a 256kbps AAC file) sounded somewhat brash and compressed, again compared with the same file sent via TosLink to the DAC. The bass guitar also sounded warmer yet better defined with the S/PDIF connection. On the other hand, Elton John and the late Leslie Duncan's "Love Song," from Elton's Chronicles album, also in a 256kbps AAC file, fared better than the Benson track when streamed from iPad to rBlink, sounding less coarse.

Changing to this song streamed from my MacBook Pro, which can use the aptX codec, brought a more natural tonality to the voices, an easier-on-the-ear quality when Elton and Leslie layer the multitracked harmonies, even though there were now two dissimilar codecs being cascaded. Benson's voice in "Nature Boy" also sounded more natural with aptX, though the sense of pace in this track seemed a bit diminished, the sound less vibrant, compared with the TosLink connection to the DAC. Overall, Norfolk Rhapsody 1 sounded closer to the S/PDIF connection from the MacBook Pro than from the iPad, though I couldn't escape the feeling that it was now a little uninvolving overall, sounding softened compared with both the iPad- and TosLink-sourced data.

These comparisons are very demanding, hence fatiguing, especially when using the very revealing Audeze headphones. They are also a great way to destroy any pleasure in listening to music you love. So once they were over, I used the rBlink for the rest of the day's music playback in my main system (see my review of the Xonar Essence One for details) while I got on with magazine work. I connected the Arcam's S/PDIF output to the Auralic Vega DAC I reviewed last month and asked the iPad, which was logged into our domestic WiFi network, to stream me some classical music from iTunes via Bluetooth.

Well, despite my philosophical reservations about lossy codecs in general, and despite my conclusions about the iPad codec in particular from the critical listening sessions, and despite the fact that I'd measured the rBlink before I listened to it, I enjoyed what I heard that afternoon and evening. A stream of Lorraine Hunt Lieberson singing an aria from Handel's Serse, "Ombra Mai Fu," sounded sweet. Nicola Benedetti and the Scottish Chamber Orchestra's recording of Vivaldi's Four Seasons didn't seem lacking in space or dynamics. Yo-Yo Ma's familiar performance of the first Bach Cello Suite sounded natural, though with perhaps a touch more rosin on his bow than I'm used to from the CD. Even Chris Thile's transcriptions of these Suites for mandolin sounded almost as convincing as they had in the hi-rez files I'd purchased from HDtracks. Almost.

Perhaps, because I was streaming classical music, there was more quality to begin with. Perhaps non-classical recordings would be more sensitive to the lossy compression. So I selected "iTunes Weekly Top 50—Alternative" on the iPad. Simple, spacious mixes, such as "Royals," from Lorde's Pure Heroine, didn't seem to suffer too much, though "Team," from the same album, sounded grainy and uninvolving, and "Sail," from AWOL Nation's Megalithic Symphony, was simply unlistenable. But both Lorde tracks sounded cleaner via iTunes and the rBlink than they did streaming from YouTube via TosLink to the Xonar DAC.

Could I have been wrong about Bluetooth audio?

Summing Up
"Am I the only one who values content and convenience over sound quality?" asked Sam Tellig in last December's "Sam's Space." He continued, "I love Internet radio via Bluetooth. So much content. So convenient, via smartphone or laptop."

In the past, I've been skeptical about Bluetooth audio, feeling that the possible sonic compromises of the necessary lossy codec outweigh the convenience, other than when it made something possible that would otherwise be impossible—such as listening to a live concert from the UK's BBC 3 via the Internet. Arcam's inexpensive rBlink has forced me to reconsider that position. No, Bluetooth audio still doesn't reach CD quality. But it was surprisingly listenable for much of the music I heard while auditioning the rBlink.

Sam was right. Plug the Arcam's S/PDIF output into your high-end D/A processor and you have a convenient and legitimate source of music.—John Atkinson

COMPANY INFO
Arcam
US distributor: American Audio & Video
4325 Executive Drive, Suite 300
Southaven, MS 38672
(866) 965-6050
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COMMENTS
deckeda's picture

John, I'd be interested to see Stereophile spill a little ink on Bluetooth solutions that handle AAC directly. The potential advantage is that the player can (and will) stream the file--unfettered--to the other end and the "Bluetoothness" aspect becomes irrelevant for those who buy music from the world's largest online music seller, or make the effort to choose AAC over some other lossy format before putting songs on their phone, regardless of brand or OS.

Azteca X's picture

Deckeda, that sounds cool but I'm not familiar with that possibility.  Can you link to some products that do so, or any technical writings or forum posts that point to this possibility?

On another note, though I am duly impressed with the rBlink, glad there is a Bluetooth receiver that has proper measurements and a digital out, etc. the elephant in the room is the Apple TV.  Using Airplay, you can use your wifi network (no pesky 25-foot rule - don't have to be on the same floor) and stream losslessly.  How do ya like them apples?  The obvious limitation is that you have to be using Apple devices, excluding a few workarounds.  But if you're using an iPhone/iPod touch, a Macbook Air or Pro or iMac or what have you, Airplay is there and it does 16/44.1 and 16/48 losslessly.  The Apple TV has an optical out and no analog out, so it's only for the DAC crowd, but it works great and has Ethernet and Wi-Fi.  It's also notable that is is only $99 new rather than $249.

Mr. Tellig, it appears you use an iPhone, so I'd love to see you try out an Apple TV.  Return it if you are not pleased!

All that said, I have a dead simple Bluetooth radio in my bedroom that I use plenty for listening to podcast while I clean up or send audio from JRiver to it using JRemote.  Choice is a beautiful thing.

deckeda's picture

I'm sorry but I don't know where I read it. This review got me researching aptX because I'd read the earlier hosanas about it here. That's when I learned all aptX transmissions require the transcode through the "aptX codec".

Somewhere in there is when I also read that AAC gets sent as-is (assuming an AAC file source) and decoded at the Bluetooth reciever.

I'm sure the devil's in the details and especially so with cheap transmitters and recievers.

**********

In my experience, AirPlaying music over to an AppleTV is a recipe for despair. All of them necessarily resample to 16/48 and likely, not terriby well. But 16/48 is ideal for most video sources, so there's that. More to the point, it's never sounded good to me for music, and not by a little bit. Could also be an issue with what happens when the audio gets sent out of the HDMI or TosLINK since ATVs lack their own DAC.

AirPlaying over to my Marantz receiver (built-in AirPlay) is just dandy, as is any AirPort Express, which keeps everything at 16/44.1 bit perfect. And by the way these comparisons were done on the same stereo system.

But I'm with you. If your source is 16/44.1 via either iTunes on a computer or iOS device, an AirPort Express is, and has remained for 10 years, the defacto no-brainer streaming solution for both ease of use and sound quality.

Azteca X's picture

Wow, thanks for the tip.  I had no idea.  Makes perfect sense for video but not good for audio.

Here is some objective verification (yes, measurements included) and details about the current Airport Express for you, Tellig, Atkinson or anyone else!  The SRC will downsample up to 24/96 to 16/44.1 - seems fair enough to me.  In my case I'm using an Oppo (and later a dedicated DAC) for DLNA with JRiver so this would be more for myself or my GF being able to play Spotify, podcasts, internet radio etc. quickly and easily without any extra fuss, sending the optical out to a DAC.

http://www.computeraudiophile.com/content/465-new-apple-airport-express-...

http://www.computeraudiophile.com/content/466-measurements-first-and-sec...

The summary:

 

  • 16 bit / 44.1 kHz music -> Bit Perfect
  • 16 bit / 48, 88.2, 96, 176.4, 192 kHz -> Not Bit Perfect but does play through the AE at 16/44.1.
  • 24 bit / 44.1, 48, 88.2, 96, 176.4, 192 kHz -> Not Bit Perfect but does play through the AE at 16/44.1.
deckeda's picture

Howver, it's nothing new. The original AirPort Express, and 2nd gen (updated to 802.11n) behaved similarly: take most any PCM and give you 16/44.

Chris at Computer Audiophile noted why this is, despite the new AE having a 24/192 DAC. It's the AirPlay standard that limits audio to 16/44. Nothing higher ever leaves the sending computer or iDevice. Doesn't matter how you setup a computer. AirPlay stipulates a transcode on the fly to Apple Lossless 16/44 regardless of the file you're playing back.

You can get the original AE used, from eBay for $40 or less and it'll be just as good as the new one for audio. Windows users might be OK as-is. Mac users would need an OS no newer than 10.7 to configure it, or a script that lets later versions of OS X run AirPort Utility 5.6.1 (The second gen AE, also likely inexpensive now, can I think still be configured with AirPort Utility 6.3)

skris88's picture

Just avoid Bluetooth if you want to pick on it's limitations. 

You cannot make a silk purse out of a sow's ear.

It's like putting wings on a car and saying it doesn't fly very well!

 

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