Rob Watts has come a long way since he “foolishly decided to get involved with manufacturing hi-fi”. After leaving Cardiff university in 1984 he cofounded Deltec Precision Audio and made a name for himself as a gifted electronics engineer. Then he moved into digital and raised eyebrows with the PDM1, his first Bitstream DAC. It was, “the first time I heard digital sounding natural and nice”, he told me. “I had been very very anti-digital, there were a number of technical reasons why I didn’t like it. It sounded so hard and aggressive and non-musical, I preferred the sound of vinyl”, he confessed…
After a designing several ground-breaking digital converters through the early nineties, Rob parted company with Deltec and it was only many years later that a chance meeting with Chord Electronics’ John Franks saw him back designing mainstream hi-fi products for the Maidstone-based company. This set in train a sequence of events that led to the beautiful and highly innovative Chord DAC64, launched in 2003.
Watts has always done digital differently; his Pulse Array DAC technology is highly bespoke. He believes that the limited number of samples that conventional DACs carry out makes them unable to accurately resolve what he calls the ‘inter-aural’ timing of the music – the audio equivalent of what you would call ‘frame rate’ on video. Having studied psychoacoustics at university, he contends that (in simple terms) the brain samples sound in real time every 4 microseconds, whereas Compact Disc refreshes its ‘frames’ every 22 microseconds. It’s this inability for CD to work as fast as the brain which causes the format’s problems in the time domain, why it doesn’t sound natural. Musical transients are lost because the leading edges of notes are effectively chopped off, meaning the brain can’t recognise them as music in the way it does when hearing live music.
The Watts Transient Aligned digital filter – which first appeared on the DAC64 – is designed to address this by sampling the ‘frames’ much faster than usual, and interpolating the values for the lost ‘frames’ between the captured ones. This is done using a powerful Xilinx Field Programmable Gate Array, rather than off-the-shelf chips from existing manufacturers. The Hugo runs a far more powerful evolution of this system, way more sophisticated than any that have come before because of the vast number of gates the new FPGA has. Watts has worked in a digital filter with a far higher tap-length than that seen in stock DAC chips – 26,000 in the Hugo compared to the approximately 150 in standard DACs.
Rob says that the DAC64’s 64-bit core was a result of being worried about coefficient truncation issues, signal truncation and other problems, and it’s for this reason it ran 64-bit words to get plenty of gate capacity. With the Hugo, he claims to have ”completely solved” the truncation issues, by employing dither and noise shaping techniques in the Hugo, while the multiple DSP cores are now 48-bit. This he claims makes for superior soundstaging precision, as well as better inter-aural timing, and better bass. “I believe the Hugo is more groundbreaking than the DAC64 was, because it has changed my appetite for music – I am listening so much more now. I knew it was going to be better than the Qute DAC, but it was devastatingly better, and in ways I had not expected”, he told me.
Just as you’d expect from a clean-sheet DAC from Watts in 2014, it can process pretty much all state-of-the-art digital formats. It supports PCM up to 384kHz including DXD, and native DSD64 and DSD128 in DoP format. The Hugo also has what Watts calls “a very high quality” digital volume control, as well as the option to plug in a set of 6.3mm headphones with a decent headphone output. This means it can be run as a high quality headphone amp, or a DAC, and the output is switchable for either. Other socketry includes RCA phono outputs, plus USB, optical and coaxial digital inputs, and aptX Bluetooth too. The problem is that the case is small, and it’s slightly fiddly to plug and unplug things; especially the RCA phono sockets and the coaxial digital in; it’s so much of a squeeze that the very first Hugos reputedly didn’t work with some types of plug!
This is the price you pay for the the Hugo being portable; like no other Chord product before it, it uses two small rechargeable batteries to provide around ten hours of clean DC power. This is only possible because of the new chip’s far lower power consumption. This has a double benefit; first it can be made portable, and second it doesn’t have to suffer noisy mains. The downside is that the unit’s various functions are controlled by small, unlabelled black buttons which are fiddly, and the connectors aren’t quite as reassuringly solid as perhaps they might be. Still, no complaints about the superbly finished, light alloy casework (100x20x132mm, 400g) and the lovely Chord styling touches, including that distinctive lens onto the circuit board, whereupon you see status LEDs light up in different colours to indicate source selected, battery charge status and Crossfeed setting. Another lens shows by different colours, the sampling frequency selected.
Sonically, the Hugo is superb. It does precisely what Rob Watts claims, which is to give an accurate and ultra-detailed sound with excellent soundstaging, image location and above all else, timing. This DAC is one of the very best ever I have heard – regardless of price – in the way it strings the music together in an emotionally believable, structurally coherent way. It times beautifully, having a natural swing to it that I have only ever heard convincingly before from Chord’s own DAC64. It’s an eerie sensation to hear Compact Disc sound so much closer to the superb timing you get from a high end turntable. It gets right into the groove, carrying the ultra nuanced aspects of the way instruments play. It’s not a profound effect, rather it just creeps up on you and you find yourself sitting there, relaxedly tapping your feet, getting pulled into the music in a way that even the very best digital converters at ten or more times the price don’t quite manage.
The Hugo can’t match the sheer bass power, amazing detail or speciality of these amazing machines of course, but it can and does make music sound naturally satisfying in a way that is absolutely exceptional. Another key aspect of this is its dynamics, which are excellent; put the Audiolab M-DAC on against it for example and you can hear the latter flatten and compress major dynamic accents – the Chord sounds far less constrained. Tonally this product is extremely neutral; it’s nowhere near as warm as the Chord Qute or the DAC64 that preceded it. Don’t buy it to make your music sound fat and fulsome. Indeed, its amazing detail is quite bracing across the midband; it is like it shines a bright light on the music. Don’t buy it to sweeten up a sour system.
Chord Electronics’ Hugo is capable way beyond its price, but don’t expect it necessarily to be for you. If you’re planning on using it as a domestic hi-fi DAC it may be better to wait until Chord launches the replacement to the QBD76HDSD, or even the next generation Qute, because this a fiddly wee thing. That said, it is a sublime design, and surely one of the DACs of the decade!