SOUND ON SOUND REVIEWS THE CONVERT-8
By Frederick Norén
To read the original article on Sound On Sound, click here.
With eight channels of mastering-grade D-A conversion, this device packs a big sound into a 1U box.
Dangerous Music have been making high-quality D-A converters (DACs) for 15 years, but until recently they were only available in their monitor controllers. Public demand, though, led to the decision to put their latest design into two dedicated stand-alone DACs, the two-channel Convert-2, and the unit reviewed here — the eight-channel Convert-8.
Layout
The front panel is admirably simple. Left-most is the sample-rate button: pressing this cycles the sample rate from 44.1kHz up to 192kHz, and on to Auto mode, which detects and automatically selects the sample rate of an external source. When the sample rate is either internally locked or receiving a proper external digital clock, the Lock indicator goes from a red to green light.
Next is a calibration button, which adjusts the maximum output level (collectively on all eight outputs) between +18, +20 or +22 dBu — it’s very handy for properly incorporating the Convert-8 in your setup.
The input section offers four different choices: USB, AES/SPDIF, ADAT and TOSLINK. Basic metering is provided by eight LED lights that turn green when signal is present and red when three consecutive samples have clipped.
Lastly, the Word Clock button toggles between three different modes: Normal, External and Master Clock mode. In Normal mode the converter slaves to the chosen digital input, in external mode it slaves to the clock present on the Word Clock input and in Master mode it acts as master clock.
The rear panel has two DB25 (D-Sub) connections, one for four stereo AES or S/PDIF inputs and one for eight analogue outputs. Dual ADAT connections allow the Convert-8 to cater for higher sample rates via the S/MUX protocol, and a digital stereo source such as a CD player can be connected via optical S/PDIF. The USB connection enables the converter to be used as an eight-channel audio interface — the manual also suggests the possibility of creating an ‘Aggregate Device’ (in MacOS), to use several Convert-8s simultaneously. The Windows USB drivers have to be installed separately, and currently are available for two-channel operation only.
By using the two RJ45 network connectors, it’s possible to control four input-selection options using the company’s monitor controller, the Monitor ST.
Design
The Convert-8 is designed around the Analog Devices AD1955 DAC chip. Although this chip has been available for 15 years now, it is still found in both professional converters and high-end hi-fi DACs. It was chosen after having conducted blind tests to compare a couple of different chips — the AD1955 chip was chosen not only by the design team, but also by a selected group of professional sound engineers.
Chris Muth, head designer at Dangerous Music, rightly explains that the chip that’s used is only one piece in the DAC puzzle when striving for the utmost sound quality. Chris emphasises the importance of proper implementation of each part in the converter, and the design team spent quite some time designing both the analogue front-end and the digital implementation — he personally fine-tuned the audio-path and the analogue low-pass reconstruction filters.
The internal digital clocking is built around the JetPLL ultra-low jitter technology that’s used by quite a lot of professional audio-interface designers, but this has been further enhanced by the surrounding circuitry — resulting in there being virtually no jitter, in the audio band and beyond. So, the Convert-8 should double up as a mighty fine master clock in any digital system.
In contrast to some other high-end D-A converters, no sample-rate conversion is performed inside the Convert-8 — simply because Chris doesn’t find that to be beneficial to the sound.
The Numbers
The leave-no-stone-unturned approach to the Convert-8’s design process means that its stellar performance comes as no surprise — but still, the published specs are impressive: the dynamic range is 114dB, the THD+N is less than 0.00188 percent at +4dBu and less than 0.0004 percent at +22dBu, and the crosstalk rejection is more than 114dBu at 1kHz. The clock jitter is less than 16 picoseconds (100Hz to 40kHz).
The Sound
It’s important not to judge it on the figures alone, though; its subjective sound qualities are what really matter. The Convert-8 offers a very well-balanced sound with lots of depth and width. The low-end goes really deep and remains punchy, which makes it easy to comprehend the relationship between a kick drum and bass instruments. The firmness of the low-end makes it a pure joy to listen to well-recorded drums, and electronic kicks sound very ‘electric’. The upper bass and low-mids sit very well together, and reveal the solid foundation of a great-sounding mix in a very natural way.
The upper mid-range is super transparent and vivid. Vocals and other centre-positioned instruments are portrayed in the most natural way. The mid-range is also very detailed towards the outer rims of the stereo panorama, sometimes generating the impression of added width to the sound stage. It’s quite subtle and in a multi-channel context, with the Convert-8 feeding an analogue summing mixer or some external outboard, the added sense of stereo width will be beneficial.
The high-end of the Convert-8 is open, airy and detailed. The transient response is remarkable: it is coherent from the low-end to the high-end, making up-front percussive instruments stay up-front and snappy, without adding any harshness. All in all, then, the sound of the Convert-8 can be described as deep and wide, and at the same time transparent and musical.
In The Mix
I had the good fortune of testing the Convert-8 along with a Dangerous 2-Bus+ when reviewing the latter for this magazine (www.soundonsound.com/reviews/dangerous-music-2-bus). Pairing the two, spreading out a mix on eight channels and listening to the result, I was instantly blown away by the transparency and stereo width. The low-end depth and punch was equally impressive, and the same was true of the transient response. Compared with my old eight-channel DAC, the Convert-8 pretty much offered ‘extra everything’.
Since that review, the Convert-8 has been acting as my main multi-channel DAC, feeding an eight-channel analogue mixer from Dangerous Music. Having worked extensively with the Convert-8 for quite some time now — and more recently having used it in conjunction with the Dangerous Convert-AD+ A-D converter — what strikes me the most is the way that it just gets out of my way. I no longer have to fight the ‘sound’ of the converters when working in my hybrid digital/analogue setup.
Summary
The Dangerous Music Convert-8 is a great-sounding eight-channel D-A converter — it is, without doubt, one of the finest D-A converters on the market. The low-end is deep and sometimes immense, the mid-range is super transparent and natural, and the high-end is open and with lots of detail. The transient response is coherent from the lowest of lows to the highest of highs. Altogether, this makes this converter suitable both for serious mixing and mastering applications.
The performance is, of course, reflected in the price. But while the competition among multi-channel interfaces is fierce, I have yet to find a multi-channel converter that can compete with the Convert-8 on both price and sound quality. It’s well worth testing in any proper control room.
