Cambridge Audio DacMagic Plus
Cambridge Audio DacMagic Plus
Cambridge Audio DacMagic Plus

Cambridge Audio DacMagic Plus: Preamplifier and DAC combined

The front panel of the Cambridge Audio DacMagic Plus is rich in indicator LEDs, however, thanks to their literally pinpoint sizes, they do not disturb the feeling of noble minimalism. If you look at the device from the rear, then due to the large number of small inscriptions and different-sized connectors, including XLR, the box is associated not so much with home Hi-Fi, but with some kind of professional module. It makes sense to dwell on the switching in more detail, since this is where one of the main features of the Cambridge Audio DacMagic Plus lies. In addition to the USB-B port, which is obligatory in these days, there are two pairs (optics + coaxial) of S/PDIF inputs, as well as similar connectors for outputting signals to external digital devices.

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There are also two analog outputs: tulips and balanced XLR. In fact, there is also a second USB port, but it is intended mainly for connecting an external Bluetooth dongle.

By and large, the Cambridge Audio DacMagic Plus is not just a DAC, but a whole combine, including a preamplifier with switchable digital inputs and a headphone amplifier. Interestingly, its volume control cascade can be switched off. During initialization, it is enough to press the volume level drum – and a linear signal will be sent to the outputs. By the way, this control is completely digital, and in order to get from minimum to maximum volume, you will have to turn it three turns. And all this time you will feel lightweight plastic under your fingers. Unlike the rest of the design elements, it is made in a rustic way, however, without touching the device, it is almost impossible to notice this.

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But let’s return to the functionality, which is simply surprisingly rich in today’s times. For example, a separate button is responsible for selecting the type of analog filtering of the DAC. Three values ​​are available: linear and minimum phase, as well as a filter with an increased cutoff slope. And if you hold this button longer, inversion of the global phase of the signal will turn on. The Cambridge Audio DacMagic Plus uses a pair of well-known 24-bit dual-channel Wolfson WM8740 chips as digital-to-analog converters. Their own characteristics: a signal-to-noise ratio of 120 dB with a total distortion of 104 dB (in single-channel mode), support for PCM signals with sampling rates up to 192 kHz and, for better or worse, no compatibility with the DSD format.

The Cambridge Audio DacMagic Plus is capable of handling asynchronous streams up to 24bit/192kHz, but there are two tricks to keep in mind. Firstly, by default its USB interface operates in version 1.1 mode – accordingly, it refuses to accept high-resolution tracks (more than 48 kHz). Switching it is not difficult, you just need to remember to do it. Well, secondly, when playing rare recordings at 32 kHz, the sampling rate indicator remains turned off. But don’t let this scare you – everything works, it’s just that there is no LED for this mode.

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Well, now the most important point. Regardless of the source parameters, any signal in Cambridge Audio DacMagic Plus is upsampled to 24 bit/384 kHz. The Analog Devices ADSP-21261 signal processor is responsible for this operation. This chip, which belongs to the third generation of the high-performance SHARC line, is programmed in accordance with ATF2 algorithms developed by the Swiss company Anagram Technologies. ATF stands for “Adaptive Time Filtering,” and the essence of this technology is interpolation of the signal envelope using polynomials. According to the creators, it works much more correctly than other upsampling methods. In addition, the process provides deep buffering of the digital stream to suppress jitter. Apparently, Cambridge Audio really takes the capabilities of ATF2 very seriously, because in DacMagic Plus it is not possible to disable it in principle.

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So, we have before us a fairly advanced DAC, to which, in addition to a computer via USB and mobile gadgets via Bluetooth, you can connect two more digital sources via S/PDIF. Thus, for example, you can integrate an SACD player, satellite receiver or game console into the setup. The subtlety is that the Cambridge Audio DacMagic Plus is a purely stereo device, and it does not decode multi-channel Dolby Digital or DTS streams. However, their switching does not cause problems, so no one bothers to receive 5.1 bitstream from the digital output and send it further to the home theater receiver.

By the way, an interesting point is that no signals are upsampled before being sent to the S/PDIF output, due to which the device can be used as a transmission media converter. For example, to connect some exotic DAC to a computer that cannot work independently via USB.

Features Cambridge Audio DacMagic Plus

D/A converters two 24-bit Wolfson WM8740 DACs
Analog Devices ADSP21261 DSP digital filter, up to 24-bit/384kHz conversion
Analog filter 2-pole dual differential Bessel filter, dual balanced with virtual ground
Frequency response 20 Hz – 20 kHz
Harmonic distortion <0.001%
Signal-to-noise ratio -112 dB
Output impedance <50 ohms
Supported input signal bit depth 16-24 bits
Supported input signal sampling rate 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz , 176.4 kHz (only for digital inputs 1 and 2), 192 kHz
Output frequency and bit depth 24 bit / 384 kHz
Connectors Two optical and coaxial inputs and one output, USB (for direct connection to a PC), XLR connectors, RCA connectors, headphone output
Maximum power consumption 12 W
Dimensions 52 x 215 x 191 mm
Weight 1.2 kg