Chord Electronics Hugo2 Review (Part 3)

4.4
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Chord Electronics Hugo2 Review (Part 3)

A Desktop Mini-Marvel

IMPROVING SOUND QUALITY

My first order of business was to maximize the H2’s sound quality and try out the ideas and comments raised in several Head-Fi posts.

Burn-In

Initially, I felt the H2 sounded very bright through my speaker setup - too bright. I was almost ready to return the unit …but after a few days of regular usage it just settled down. Was this burn-in? I was the last of the tour reviewers and the unit most certainly had many hours on it. Was it the connection to my power amp that removed the last vestiges of cobwebs in the output stage? Unsure …but the transformation was real and not a situation of ‘brain burn-in’. The H2 was screechy for a few days then became sublime. So, buyer beware, a longer home audition may be needed for your H2 to become best friends with your speaker setup.

Filters and EQ

Maybe I’m sensitive to these things but I found the H2’s crazy detail to be almost the detriment of a pleasing presentation and dream weaver listenability. I expected the filter settings to dramatically change things but I found it very hard to hear any differences. Every setting still had huge amounts of high frequency, although it seemed like Red sounded the smoothest. With H2 you’re paying for taps and I didn’t want to lose out on the 256fs up-sampling so, in the end, I went with Green and dialed in a touch of JRiver EQ high shelf to tame down my Voxativs. This setting worked very well for all music genre’s and all bitrates.

I noted that H2 revealed so much new information in my reference tracks that they sounded like different recordings. It’s like the H2’s FPGA snuck a few more singers and performers in the back door. I was expecting ‘more of the same only better’ but instead I got doses of unfamiliar depth, hidden voices and instrument nuance – all beautiful. H2 really was transformative to the music and reaffirmed how important accurate sources are when determining what other aspects of your system may need attention.

H2 thru Pre-Amp – Yes or No

Audio pre-amps buffer input/output impedance and provide gain with a volume control. The H2 incorporates a digital volume control more accurately than any pre-amp and has a well-designed output section to allow direct input to a power amplifier. So, easy-peasy, no need for a pre-amp with H2, right? Well yes and no. If you really need a pre-amp to support phono or analog inputs, be aware that I found the H2’s ‘line-level’ setting of 3V RMS to be too high for my microZOTL. I obtained a much more pleasing sound when I dialed my pre’s volume gain to near maximum and set H2’s sound volume to below 2V. I suppose this is something to do with the interplay of DAC/Amp gain/impedance curves. Direct to my ZOTL40 amp the H2 sounded better as confirmed with several back-and-forth tests. I was after transparency so I ran the rest of my review with DAC direct to amp.

Chord Electronics Hugo2 Review (Part 3)

LTA microZOTL Pre-Amp

Chord Electronics Hugo2 Review (Part 3)

LTA ZOTL40 MkII Amplifier

USB Input – Conditioning Needed?

The H2 comes with a factory USB cable – nothing special – but it does work quite well directly connected to a computer source. Rob Watts gallant attempt with increased filtering in lieu of proper galvanic isolation has really helped. I compared this with my external isolation and listened intently for distortion signatures I know are due to analog noise intrusion to the DAC. I was struggling with confirmation bias but I will say that my external USB isolation may have brought forth a tad more clarity, snap and a smoother sound. So, I’d suggest that after buying an H2, go shell out for your trusted USB isolation solution …just to be sure.

Power & Battery

The importance of clean power feeding a DAC cannot be overstated – as any negative impact on the small signal D/A processing becomes quite audible when amplified. H2’s battery operation definitely gives it a huge advantage here – obviously making it immune to AC noise and ground loops. I got 6-7 hours battery operation and while charging I could discern no difference in the sound. The brilliant engineering by Rob Watts really works to isolate the delicate bits of the DAC from the terrible world of household power. This feature alone has me rethinking the value and importance of floating my entire source chain off the grid: laptop, USB cleanup and DAC. Then I can be assured that my RCA interconnects carry the DAC’s absolute best quality analog signal to my amplifier. Thank-you Hugo2.

My other review DACs all relied on AC power and definitely needed power conditioning to sound best. To offset the H2’s battery-only advantage over other DACs, I tried using a UPS (APC SmartUPS 1500) to provide a maximum of about 90 minutes of power to each of them. This may have helped - although the H2 still embarrassed the lot by dominating in sound quality. More below…

I was fortunate to have demo Nordost QKore ground units during my review. These work to silence spurious noise on the AC mains as well as component signal ground – like sticking a proverbial thumb on the buzzy spot. The H2, being battery powered, was not bettered by improved signal grounding. Other AC powered DAC’s, however, did marginally improve (deeper silence I felt) and were thus configured during my comparisons. Mostly, QKore delivered the best benefit to my AC powered ZOTL40 amplifier by grounding the RCA inputs (and by extension, the DAC’s RCA outputs and analog section).

Chord Electronics Hugo2 Review (Part 3)

Nordost Power Conditioning

Chord Electronics Hugo2 Review (Part 3)

QKore Ground Units

DSD vs PCM

Rob Watts has made his opinion on DSD well known – and emphasized his PCM-first approach for his DACs. However, somewhere during the development of the H2, the decision was made to give DSD content the same high regard as PCM. Exact details are unclear but I understand it’s a parallel implementation to his PCM approach and the results are very good. DSD playback (64x,128x,256x) plays flawlessly and with the same fidelity as PCM frankly. I looped several tracks for which I have both versions and loved them equally. I’d probably need better ears or a more resolving system to discern the differences.

Lossless vs Redbook vs Hi-Res

Any song played from my Google Play Music subscription (at an “effective” 320kbps resolution) was almost as satisfying as the lossless 16/44.1 version from JRiver or Tidal. Using the H2 to stream background music while trying to answer emails or preparing dinner proved highly distracting to the task at hand. Even at muted volume levels, the bass has wonderful impact and even whisper vocals carried great emotion. High resolution lossless versions sounded impressively more smooth and real …but Rob Watts WTA filters really work well across the source quality spectrum. Still, in quiet, intimate listening sessions (like after 1am with a glass of bourbon in hand), there is no comparison to the joy of 96khz music.

Direct to Loudspeakers

It has been noted that a Chord DAVE can directly drive high efficiency speakers. DAVE provides about 2 Watts of power into 8Ω to deliver the ultimate in transparency – or so go the comments from those few souls who have this kind of setup. I felt I needed to try it with H2 and even though it’s power output into 8Ω is only about 1 Watt it would be enough to drive my ~99dB efficient Voxativ speakers to listenable volume levels. To connect the RCA plugs on H2 to my speaker cable, I used adapters purchased from Amazon - although directly wiring an RCA end on the cable would probably reduce losses.

Chord Electronics Hugo2 Review (Part 3)

Speaker wire connected directly to Hugo2’s RCA outputs

Chord Electronics Hugo2 Review (Part 3)

UXCELL BNC to Dual Banana Binding Adapter with matching RCA connectors

And the sound is …Holy Transparency Batman! I thought my ZOTL amp was the final word but the H2 directly controlling Voxativ neodymium drivers sounded so much more realistic with authentic echoes from a deep soundstage that transported me to the recording venue. I heard visceral lows, incredibly detailed voices; a beautiful mid-range and effortless highs that just floated off the speakers. The nearly distortion-free linearity of the H2 amp was quite apparent – I noticed a purity in the mids that I found very enjoyable. This was the sound of headphones through loudspeakers. I was transfixed and will join the chorus of persons who say that this approaches the ultimate. For me, it’s the best I have ever heard.

That being said, I did notice a certain thinness in the delivery: less authoritative drum slam and slightly diminished body in general. Also, the digital nature of the H2 was laid bare without any interconnects or tubes to mellow the sound. So, it was gloriously transparent but at the same time …uncomfortably so. I returned my ZOTL to the mix and got back the ‘meat on the bones’ – as they say - but immediately sensed the loss of definition. Hmm. I wanted to go back to H2’s amp but its battery-based power supply just couldn’t provide the power (current) needed to move loudspeaker magnets with aplomb. Oh boy, what to suggest? Just add a subwoofer and call it a day? Upgrade to DAVE? Wait for Chord’s anticipated Digital Amps? For sure, once you have heard this kind of full transparency, there is no going back.

Software Up-Sampling

The H2’s ability to accept PCM768 and DSD512 means it can handle software up-sampled music and only the final conversion to analog is done by the H2’s pulse array hardware. The mediocre SoX up-sampler within JRiver easily ran on my laptop but produced vastly inferior audio. HQPlayer is a well-known media player with a very powerful up-sampling engine – arguably the best in the world. The most recent version includes ‘xtr’ filter options to mimic the ‘Chord Sound’ - says designer Jussi Laako. Despite Chord’s claims to the contrary, modern CPU’s are well capable of filtering at high tap counts and HQPlayer’s can run into the millions. Does this mean we can duplicate WTA filters and turn the H2 into a DAVE, or better? My laptop was not the most performant so I limited my tests to the PCM filters ‘poly-sync- xtr-mp’ with standard noise shaping – and these ran in real-time with no problem.

The results were interesting. I’d say that HQPlayer produced files almost as smooth as DAVE and there was a bit more lushness to everything. I found the instruments sounded more natural and I believe I also heard a deeper and wider soundstage. But overall, the HQPlayer up-sampling was not as magical as the H2 on its own. This certainly warrants more experimentation. So, you can consider H2 to be both a fantastic up-sampling DAC voiced by Rob Watts or an excellent D/A output stage that can accept software up-sampled PCM or DSD.

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