- Created on Tuesday, 15 May 2012 05:00
- Written by Vince Hanada
Digital-to-analog converters have been popular almost since the introduction of the Compact Disc, in 1983. I can understand why DACs were needed in those early days -- CD players’ built-in DACs were of dubious quality, and manufacturers cut corners to bring costs down. But as CD players improved, I couldn’t be bothered with an external DAC, and the two-box solution of CD transport and separate DAC introduced another problem: jitter, or timing errors in the transfer of data between transport and DAC. When jitter reaches a certain level, it becomes audible.
These days, with the diminishing use of CD players and the growing use of computers for storing and playing recordings, standalone DACs have again become important for good sound, especially the playing of high-resolution recordings. SACDs are becoming increasingly scarce, DVD-Audio is dead, and Blu-ray audio has not picked up the hi-rez music banner in any significant way. The simplest way to get hi-rez music these days is to download it from websites such as HDtracks, and play it on a computer through your audio system.
The DAC reviewed here is Cambridge Audio’s Azur DacMagic Plus, a follow-up to their highly acclaimed Azur DacMagic. The price has gone up a couple hundred bucks, to $650 USD, and some worthwhile enhancements have been added.
The Azur DacMagic Plus hails from the half-size school of audio design, measuring just 8.6”W x 2”H x 7.6"D. The advantage is that the DacMagic Plus fits almost anywhere -- it even comes with a stand so that it can be positioned vertically. The disadvantage is that some won’t take it seriously; the minute I mentioned its size to one audiophile buddy, he dismissed it.
One thing that makes the DacMagic Plus a more serious component is the presence on its rear panel of XLR and RCA outputs. Balanced XLR connectors are normally seen only on high-end products, so it’s a treat to see them on so low-priced a model. Balanced connections offer the potential for less noise. There are also Digital 1 and Digital 2 inputs, each equipped with coax and TosLink connections, as well as an asynchronous USB input (type B), and an input labeled Ext. This last is for an optional Bluetooth adapter, which permits wireless streaming from a Bluetooth-compatible device such as a phone or laptop.
The DacMagic Plus’s brushed-aluminum faceplate and case of steel, both dark gray, give it a businesslike look. On that front panel are an On/Off switch, a Source button for selecting among the four inputs (Digital 1 and 2, USB, Ext.), a Volume knob, a Filter/Phase button, LEDs that indicate Phase and the incoming sampling rate (44.1, 48, 88.2, 96, and 192kHz), and a 1/4” headphone jack. The Filter/Phase button is for initial setup, and toggles between 0 and 180 degrees. For everyday use, its Filter function selects among three filter modes: Linear, Minimum Phase, and Steep.
The DacMagic Plus’s volume control increases its versatility: You can hook it up directly to a power amp, for a minimalist music system. The control can also be configured to have a fixed output when the DAC is connected to a preamp. One thing missing is a remote control, for selecting digital sources and adjusting the volume. Perhaps this can be incorporated in the next version.
In the box
The Azur DacMagic Plus has two Wolfson WM8740 24-bit DAC chips in dual-differential mode, which Cambridge calls its Dual Differential Virtual Earth Balanced filter topology. The Wolfson chip, a favorite of Cambridge’s, appears in many of their products, and supports sampling frequencies up to 192kHz and word lengths of 16 to 24 bits. From there the signal is upsampled to 24-bit/384kHz by a 32-bit Analog Devices DSP using a sophisticated algorithm developed in conjunction with Anagram Technologies, and which Cambridge calls ATF2. The result, they say, is dramatically reduced jitter.
The Azur DacMagic Plus was easy to set up, but there are a few things you need to know. First, if your computer runs Windows 7, you’ll want to download the Windows 7 audio stream input/output (ASIO) driver from Cambridge Audio’s website. This will not only allow you to play 24/192 files; it also bypasses the Windows system mixer, for better sound. (Macs pass along 24/192 files without additional drivers, rendering this step unnecessary.)
If you don’t already have software on your computer for playing hi-rez recordings, foobar2000 is free and an excellent choice. The Cambridge Audio website posts step-by-step instructions for setting this up, though it takes a bit of work: downloading a driver and choosing the right settings. Be sure to follow the directions, or you’ll be wondering why your 24/192 file is being played at 16/44.1. Other recording formats -- MP3s, CDs, and 24/96 FLAC files -- played without incident.
I ran the Azur DacMagic Plus through a battery of listening tests with a variety of hi-rez tracks, mostly played through my laptop running Windows 7 and foobar2000, connected to the DacMagic through the latter’s asynchronous USB port.
A great place to get free hi-rez demo tracks is from the Norwegian label 2L. A particularly revealing one is Øyvind Gimse conducting the Trondheim Soloists, a string orchestra, in the Finale of Carl Nielsen’s Little Suite for Strings (24/192 FLAC, 2L). The violins sounded silky, extended, and smooth through the DacMagic Plus. Due to this recording’s enormous dynamic range, you’ll want to play it loud -- as the sound of the orchestra swells and diminishes, you’ll be able to hear all the subtle sounds, such as the pizzicato toward the end. Another benefit of 24/192 resolution through the DacMagic was hearing this track’s huge soundstage. It extended wide and deep, beyond the outer edges of my speakers, with imaging that was simultaneously pinpoint and holographic.
Adjusting the settings of my computer, I was able to downsample the 24/192 recordings sent to the DacMagic to 24/96, 24/48, and 16/44.1. In my listening tests, the audible superiority of 24/192 over lower resolutions was definitive. The most obvious difference was the widening of the dynamic range as the resolution increased. With the Nielsen track, the silky highs clearly evident at 24/192 sounded harder at 16/44.1. The wide, deep soundstage also collapsed in height and width at 16/44.1, appearing only between and not beyond the speakers. The DacMagic Plus definitely benefited from the best source material I could give it, and had enough resolving power to let me hear the differences among the various resolutions.
Another particularly good-sounding track is “A Shine on Your Shoes,” from jazz singer Jane Monheit’s Home (24/96 FLAC, Emarcy/HDtracks). Monheit is accompanied by a three-piece band and guest guitarist John Pizzarelli. The soundstage was particularly well sorted through the DacMagic. Although the scale was smaller and more intimate than with a full orchestra, Monheit’s voice was solidly in the center, with Pizzarelli’s distinctive playing style easy to pick out in the right speaker. His guitar sounded glossy, but not so much as to obliterate any detail. The piano, bass, and drums didn’t seem to be recorded with as much precision, but one particularly solid image was the plucking of the bass strings to the left of center. Bass notes were particularly solid and strong through the DacMagic.
One concern I had with the Azur DacMagic Plus was the inability to play 24/176.4 tracks through its USB port (it will play this resolution through the Digital 1 and 2 inputs). To listen to these, I had to burn them to a DVD-A disc and route them through my Oppo BDP-83 universal Blu-ray player’s digital output. The DacMagic lacks an LED to indicate the 176.4kHz sampling rate; when such a signal is received, all sampling-rate LEDs go dark, though it plays fine. One 24/88.2 track I became familiar with from the 2L-TWBAS 2012 Sampler (2L and SoundStageRecordings.com) is BNB’s “Et minne dypt.” The delicate violin and female voices sounded remarkably real through the DacMagic, which well preserved the music’s melancholy mood.
Although MP3 recordings are out of place with the hi-rez DacMagic Plus, I played one of my few MP3s, “Dog Days Are Over,” from Florence + the Machine’s Lungs. I expected to find the sound thoroughly disappointing, but it was good enough that I didn’t run screaming from the room with my hands over my ears. Once again, the silkiness of the DacMagic’s high frequencies made listening to it quite enjoyable. When the music got loud and forceful, I found the DacMagic Plus sorted through the confusion to present an orderly soundstage.
I gave each of the Azur DacMagic Plus’s three digital filters -- Linear, Minimum Phase, and Steep -- a good listen, and overwhelmingly preferred Linear. When I listened to Crux Fidelis (Anon.) sung by the male choir Consortium Vocale Oslo, from the 2L-TWBAS 2012 Sampler, the Linear filter extended the spread of the men’s voices far beyond the width described by the two speakers. Both the Minimum Phase and Steep filters reduced that spread a bit, and the sound was darker overall. With the tracks I tried, I heard no difference between Minimum Phase and Steep, but both sounded more aggressive and dark. This aggression was evident with “If It Wasn’t for Bad,” from Elton John and Leon Russell’s The Union (24/96 FLAC, Decca/HDtracks), which is in keeping with the theme of this song. John and Russell were much more listenable and involving through the Linear filter. I can see these filters working well with tube electronics, but with my solid-state gear, Linear was the way to go.
As a preamp
Cambridge Audio’s inclusion of a volume control and headphone jack in the Plus increases the versatility of the original Azur DacMagic. In a minimalist system feeding my power amp, the Plus put the noise floor a notch lower than where my preamplifier-processor had it. The Plus’s headphone amp was robust enough to drive my Grado SR100 ’phones to loud levels with the same smooth, extended highs I experienced with my loudspeakers, though the double-bass notes in “Light My Fire,” from Patricia Barber’s Modern Cool (CD, Premonition/Blue Note 90761), were a bit light through the Grados. Besides this trait, this setup was let down as an ideal digital preamp only by the lack of a remote control for switching sources and adjusting the volume.
The closest competitor to the Azur DacMagic Plus that I’ve had in my system is the Arcam rDac ($479). The rDac has single connections for coaxial, TosLink, and asynchronous USB (type B). Similar to the DacMagic, the rDac sports Wolfson DACs, although it has the WM8741 chip rather than the Plus’s WM8740. Like the DacMagic Plus, the rDac can also connect wirelessly, although the Arcam is more versatile: its options include an iPhone/iPod/iPad dock and a USB dongle for wireless connection to a PC. In the DacMagic Plus’s favor are a volume control and a headphone jack that let it function as a digital preamp.
The Cambridge Audio can play 24/192 tracks through its USB connection; the Arcam is restricted to 24/96. Although I didn’t have the rDac on hand for a direct comparison, as described in the “Listening” section above, I found that 24/192 tracks played through the DacMagic Plus were audibly superior to 24/96 files. My listening notes show that the rDac sounds dark overall, whereas the DacMagic Plus was smooth through the high frequencies.
Listening to “Ode to Billy Joe,” from Patricia Barber’s Café Blue (CD, Premonition/Blue Note 90760), the double-bass notes were equally powerful through both DACs, but through the DacMagic Plus the finger snaps sounded more real. The Plus’s selectable filters let you adjust the sound quality to suit your taste, something the Arcam rDac lacks. When I switched in the Steep filter, this track sounded more aggressive. Although the Cambridge Audio lacks the Arcam’s wireless convenience features, its superior sound, the versatility of its volume control, and its headphone jack make the Azur DacMagic Plus worth the $171 difference in price.
Cambridge Audio’s Azur DacMagic Plus is a fantastic audio component and an even more phenomenal value for the money. For only $650 you get a digital preamp, a headphone amp, and a truly excellent DAC -- and being able to listen to 24-bit/192kHz tracks through the DacMagic Plus was a mesmerizing experience. If you’re looking for a DAC, even if only to add a USB connection to your system, it would be worth your while to check out the Swiss Army Knife of DACs: the Azur DacMagic Plus. It may get you thinking up new ways to configure your audio system and listen to music -- always a good thing.
. . . Vince Hanada
- Preamplifier-processor -- Emotiva UMC-1
- Amplifier -- Rotel RMB-1075
- Speakers -- Monitor Audio Silver RX6
- Sources -- Oppo BDP-83 universal Blu-ray player; Acer Timeline 1810T laptop computer running Windows 7, foobar2000
- Cables -- Analysis Plus Blue Oval in-wall speaker cable and Super Sub interconnects
Cambridge Audio Azur DacMagic Plus Digital-to-Analog Converter
Price: $650 USD.
Warranty: Three years parts and labor.
Gallery Court, Hankey Place
London SE1 4BB
North American distributors:
Audio Plus Services (US)
156 Lawrence Paquette Industrial Drive
Champlain, NY 12919
Phone: (800) 663-9352
313 Marion Street
Le Gardeur, Quebec J5Z 4W8
Phone: (866) 271-5689