Introduction:
Before I begin with my actual review, I want to thank Mass Fidelity and Blonde2.0 for providing me with a sample of the Relay Bluetooth DAC in exchange for my honest opinion. Please note that I’m neither affiliated with Mass Fidelity nor Blonde2.0 and this review reflects my actual thoughts on the Relay.
I remember, about 10 years ago, when Bluetoooth was still in the Stone Age and the first wireless hi-fi products with Bluetooth features hit the market, I had my first experience with this new wireless transmission method when I bought a portable receiver from the well-known manufacturer Philips. The small black plastic device had a weak battery life, lots of hiss, didn’t support higher-end transmission codecs (as they weren’t invented for Bluetooth back then) and had a quite miserable audio quality in general with loads of artefacts, compression and static noise.
Ever since, Bluetooth has continuously advanced and received new audio codecs support, making higher bitrates possible, towards codecs that in theory are on the same sonic level as audio CDs.
In the last years, only WiFi streaming was seen as worthy in high-end circles as only alternative to wired playback, but Bluetooth nowadays is more and more coming in this field of application and could displace WiFi streaming or at least become a qualitatively equivalent alternative.
In the near past, there were some aptX- and AAC-supporting Bluetooth devices that could convince me, and so I will find out in the course of this review how the Relay Bluetooth DAC from the Canadian manufacturer Mass Fidelity fits in.
Technical Specifications:
MSRP: $249
Input Power: 5 Volts DC 1 A
Output Power: 2 Volts RMS
Compatible Power Systems: 110-240 Volts
D/A Converter: Burr Brown 5102, 24 Bit
Bluetooth Module: aptX enabled CSR module
Bluetooth Range: 10 m; 30 ft
Enclosure: Machined aluminium
Dimensions: 115x100x36 mm; 4.6”x4”x1.4” (LxWxH)
Weight: 380 g; 13.4 oz
Unboxing, Delivery Content:
My initial impression when I saw the Relay’s plain modern packaging was already very positive. On the front, there’s mainly a picture of the device; the back contains a brief description and mentions some benefits the Bluetooth DAC has got.
The white packaging I just described is actually a cardboard slipcase; the actual packaging is covered by it and dark grey, with a window on the left side through that the Relay can be seen, and has got a circulating white recessed strip on the sides with the proud words “Designed in Canada” and a maple leaf on it.
Taking off the lid, one will find the DAC on the left, which is welded in transparent plastics, as well as a labelled “accessories” box on the right which has got a magnetic flap, containing the power supply that can take 110 to 240 Volts, three socket adapters for the European, American and Asian market, a screwable Bluetooth antenna, a multilingual user manual and last but not least two valuable interconnection cables of these one has got RCA connectors on both sides and the other RCA connectors on one and a 3.5 mm plug on the other side. This means that no additional accessories are required to getting started, which I didn’t expect, but find extremely helpful.
Looks, Feels, Build Quality:
The packaging’s premium impression continues on the Relay itself, which is machined out of aluminium, weighs 3380 grams and is so small in terms of dimensions that it is on its longest side just a tad longer than the iPhone 4 and slightly lower than my computer mouse.
The DAC which has got four rubber feet on the bottom that cover the screws and guarantee a secure stand has the Mass Fidelity Lettering lasered on its front side and “Relay by Mass Fidelity” on the top, along with a tiny LED. From the left to the right on the back, there are the terminal for the power supply, recessed RCA outputs, a screw terminal for the antenna and the multifunctional on/off button which has got a soft, but well defined pressure point wherefore the Relay stays in place when it is being pressed.
Just like the products from Apple, the upper part of the Relay was machined out of a whole block of aluminium and then screwed with the (also aluminium) bottom plate.
The premium enclosure feels very good, doesn’t have a single flaw or sharp edge and features extremely precise and tiny clearances on the bottom, which indicates that the parts are extremely precisely machined.
Features:
The small DAC has got some handy features that can’t be seen/known without taking a look at the manual. Sure, there’s a status LED on the top and the rear features analogue RCA outputs and a regular on/off button – that’s what one could think, but the Relay has got more to offer.
The DAC is commonly turned on by a short press on the multifunctional button that is located at the back, whereupon the shining red stand-by LED on the top changes its colour into a blueish white, indicating the Relay is turned on, and turns red again with another touch of the button, which indicates that the DAC is in stand-by mode again. But that wasn’t all – the Relay features an automatic switch-off function that turns the device off after 30 minutes of inactivity. It can be turned off by pressing the button for ten seconds, whereby the LED changes its colour to orange after five seconds along with a relay clicking in the Relay, and switches back to white again after five more seconds of continuous pressing, indicating the automatic switch-off function has been disabled. Disconnecting the DAC from the power supply will turn it on again.
But what does that orange shining LED indicate? Pushing the button for five seconds, a relay inside of the Relay switches the analogue RCA output to a digital SPDIF output, allowing to connect one (actually two) separate external DACs. Pressing the button once again for five seconds will switch the RCA outputs back to analogue stereo, along with the LED shining white again.
Generally, I want to mention that with iDevices, a wireless volume control is possible, wherefore the Relay could be directly connected to active monitoring speakers if used with an Apple device. With my BlackBerry Q10 which was the second transport device I that I tested the DAC with, there was no Bluetooth volume control possible.
Connecting Transport-Devices:
Connecting devices couldn’t be easier: the package promises a one-minute set-up with the slogan “Plug. Connect. Play.” underneath it, which implies easy set-up and handling.
In reality, start-up operations are truly as Mass Fidelity connotes: once the power adapter is in the wall socket and the Relay is connected to the stereo system with the cinch cables, one can directly start the action after powering the device on.
There’s no classical pairing required with the transport device, but the Relay is just selected in the Bluetooth settings where the available connections are shown (and then connects automatically to the Relay in the future) and then music playback can be started.
“Plug. Connect. Play.” is reality and usability at its finest, with easy operation.
Wireless Range:
With two walls between me and the Relay, I could achieve at least 14 meters (more wasn’t possible at my place) with the iPhone 4 and the BlackBerry. That is pretty impressive.
In reality, I doubt that the distance between the transport device and the DAC will ever exceed seven meters, but it is good to know that even more is possible.
Sound:
Relay’s sound was evaluated with two speaker rigs and two headphone rigs.
The first speaker rig consisted of two Pro-Ject Amp Box Mono as power amplifiers, which (due to reasons of size and the preference of digital amplification at home) replaced my high-end Pioneer amplifier from the late 80s. I also found them to be my favourites in the price range below €1000. The used preamplifier was a digitally operating attenuator from Sure Electronics that I chose instead of other real digital preamplifiers (I searched quite long but didn’t find anything that really convinced me below €600), as it has got outstanding measured values and doesn’t alter the sound at all, has zero hiss and adds nothing to the sound and leaves it sonically and metrologically untouched.
Main speakers were my Swans M1 compact speakers which could be denoted as solid (lower?) mid-fi – I just specialised in headphones and prefer them over actual speakers in a listening room, though I wouldn’t mind having a nice pair of active studio monitors if I had a separate treated listening room.
The second pair of speakers were my DIY speakers that were built after the plans for “Cuburgs Needle”, a TQWT construction with trap circuit and the Tangband W3-871 fullrange transducers, which are inexpensive in terms of solely material price, but play very clean, deep and balanced for fullrange speakers and are used as computer speakers by me.
The two headphone rigs contained of the Yulong U200 with the Sennheiser HD 600, HD 800 and Audeze LCD-X, as well as Leckerton UHA-6S MK.II with my Ultimate Ears Reference Monitors customs, Etymotic ER-4S, Shure SE846 and Sennheiser IE 800.
Transport devices were my BlackBerry Q10 which supports the lossless aptX Bluetooth codec and my iPhone 4. Files were stored as FLACs, WAVs, AACs and MP3s.
Measurements, Frequency Response:
Effectively linear and without artefacts were my measurements of the Relay’s frequency response with the BlackBerry as transport device:
The remaining graphs of distortion, SNR, dynamic range etc. are also extremely well, but as my audio interface always displays the 10 to 20 dB below reference measurements, I forego to uploading them (as usual), but they really show excellent values.
My frequency response measurements on the other hand are always representative and accurate.
Solely by looking at the measurement diagrams, I really couldn’t say that the measured device is a Bluetooth receiver because of its outstanding performance.
Resolution, Precision, Soundstage:
Speaker Rig:
With both pairs of speakers, there was no audible hiss, just as expected. Other kinds of noise like humming, static noise or sparkling couldn’t be detected either, which gives me the clue that the Relay has got a well-constructed circuit – but as In-Ears are more revealing and critically behaving due to their much higher sensitivity, I will move this test to further below.
As expected from a well to excellently constructed Bluetooth DAC, sound was transparent, clear, dry and particularly neutral and I couldn’t make out the difference between wired and wireless operation. The Swans’ bass remained firm, without softening, and its ribbon tweeter played high frequencies without any distortion or artefacts, wherefore the Speakers didn’t lose any bit of precision compared to wired playback.
Instrument separation and –placement remained unaltered precise and the yellow ribbon tweeter placed instruments on the Swans’ imaginary soundstage, that is inherently very wide, precisely and sharply separated from each other.
That wasn’t much surprising for me, as my room is well damped, but miles away from fulfilling studio-acoustic standards and is mainly used as home office and not as listening room, wherefore I have to rearrange the speakers each time I want to listen to music (related to the Swans, as the Needles have got their fixed position behind my L-shaped work desk) and a listening test not long ago showed that the cheaper Nubert nuPro monitors I used to own exceeded the Swans, although I also use them in near-field setup, in every aspect except for the instrument separation, so let’s get on with the more critical headphones and IEMs.
Headphone Rig:
I started with the Yulong and my full-sized headphones.
Just like with the speakers, I couldn’t detect any additional hiss or noise from the DAC, but full-sized headphones are less prone to detecting hiss and noise than In-Ears due to their lower sensitivity and will mostly only reveal noise and hiss if the source device has got lots of it, which the Relay obviously doesn’t. Static noise was also not present and what I heard was still neutral, precise and transparent.
No softening bass or dull lows were audible, although planar magnetic headphones like the Audeze LCD-X are very sensitive to such things, as my experience has showed, but there was nothing of the sort with the Relay. Also in the highs, which often sound a bit less detailed with Bluetooth, I couldn’t hear any weakness, because details were clear, clean, present and lacked of any artefacts, just as with wired playback.
So then I moved on with my In-Ear rig with the Leckerton.
I started with the iPhone as transport device.
First of all, I tested if I could detect any his or noise with the above-mentioned IEMs (UERM, ER-4S, SE846, IE 800), playing an empty audio file. To my great joy, I couldn’t spot any negative things and there wasn’t even additional hiss – that’s perfect!
Thereafter followed the actual listening test which was extremely surprising: I expected the Relay to be a good to excellent Bluetooth DAC, but my expectations were surpassed: bass remained unaltered arid, precise, firm and controlled and I couldn’t hear any difference between the Relay and wired audio transfer. Overall resolution was very high and if I hadn’t known, I wouldn’t have believed that a Bluetooth DAC was in the audio chain. Solely with MP3 files on the iPhone (although they were stored as 320 kBps cbr) I had the feeling that there was minimally less precision in highs’ decay and I thought that the soundstage was marginally smaller, but speaking honestly, those differences, if they even existed, were so minor and I had to swap back and forth very often to even get the feeling that there was some difference, that I am quite sure it was autosuggestion (“a Bluetooth DAC has to be worse than a wired one”, told me my subconscious mind) and I’d bet money that I wouldn’t be able to detect any difference in a blinded test where I could switch between the Relay and wired connection without delay and with matched volume levels.
Then I went on with the BlackBerry that has always shown the best Bluetooth results in the past. Honestly: regardless what audio format was played, I couldn’t detect a single difference between wired and wireless decoding. Everything was just plainly clear, precise and high resolving, without any artefacts or loss of soundstage, which got me lost for words – even with the highly critical IEMs, the Relay remained flawless.
Conclusion:
Mass Fidelity has really produced an awesome Bluetooth DAC with their Relay. It doesn’t only feature a plain, timeless design and flawless build quality, but also an integrated switchable digital output which is actually not really necessary due to the impeccable audio quality.
Sound is neutral in the best sense of the word and just like as one would expect an excellent DAC to be – it isn’t noticeable in the audio chain as it is audibly transparent and plays objective instead of doing whitewashing, just like a well-constructed amplifier also should behave.
Even with critical In-Ears which are in my experience the most weakness-revealing type of headphones, I can’t detect any flaws and the sound isn’t a tiny bit worse than with good wired audio connection – Mass Fidelity shows that Bluetooth can be just as good as a wired signal transmission and WiFi decoding, which seemed to be impossible to achieve just a few years ago. Though, a transport device that supports aptX and/or AAC Bluetooth streaming should be used to achieve the best possible sound quality.
Truthfully, I can’t see any weaknesses on the Relay’s side and solely the somewhat too tight sitting interconnection cables that come included and the for my tastes too bright LED are the only things I could find – with speakers and even with headphones, the Relay Bluetooth DAC is just sublime.
I'm really sorry about the inconvenience as this normally does not happen.
Please reach out to me at support@massfidelity.com if you need anything else at all. Thanks!
Andrew from the Mass Fidelity Team