This is my reiew of Audio-gd NFB-9.2. After having sold my modded Museatex Bitstream, I have been in search for the perfect dac (or a more perfect dac), which could replace it for its believable tonality, its wonderful sense of colour and reality given to instruments, possibly offering better versatility (bitrate, inputs, general usability) than the Bitstream could.
I have tried Assemblage DAC2.7, for example, but I found its stock form a bit underwhelming. The Assemblage was a clean source, but it lacked the sense of power, analogue tonality and spaciousness that the Bitstream was offering.
The Assemblage lacked any real top digital glare, but it was a grey sounding source, not so alive.
As of late, I have acquired the Audio-gd NFB-9.2, and Eximus DP-1 (under suggestion of the buyer of said Bitstream), which I am still evaluating.
I also had been loaned a Burson HA-160DS (with purchasing option, but I wasn't interested in keeping it), so I could also compare its dac section.
Headphones I have been testing the NFB-9.2 with, are:
Apuresound Etymotic ER4P/S
Etymotic HF5 (with and without PtoS adapter)
I will receive Audio Technica AD2000 soon, which I hope will end up being my go-to headphone, after being intrigued by Asr's review. I will add comparisons on it.
Burson HA-160DS amp part.
Eximus DP-1 amp part.
VH Audio RCA
Moray James analogue cables
Some random Fudao cables
The Audio-gd uses dual Wolfson WM8741 dac chips, has several inputs (including usb with its newer Tenor TE8802 chip, whose upgrade marks the model change from the former 9.1), and offers both single ended and balanced output.
The dac comes with a remote for digital volume control. It works well, with no apparent sq degradation for slight volume changes, although as a rule I prefer to regulate volume through the amplifier.
The general character of the DAC is spacious, powerful, weighty; offers big images through headphone listening. It's transparent, there is a bit of edge in the highest frequencies. The detail reproduction is very high. The bass is pretty tight, there is sense of power. Images in the midrange are big, although not as focused as the Eximus DP-1.
The DAC is miles better than the one offered with Burson HA-160DS. The Burson's dac is targeted to the 200-300$ range. I have described it as a bit empty sounding. Switching to the NFB-9.2 provides improvements in every area: the sound gets much more spacious, detailed, powerful. The midrange gets more neutral. Using Burson HA-160 DAC/amp makes the listener feel like the DAC is the weakest part in the chaing. Switching to an Audio-gd NFB-9.2 -> HA-160 (amp only), the "values" are switched, and the NFB-9.2 takes the part of the "star" in the system.
With some upper treble energy excess, the Audio-gd DAC makes the detail rendition pretty uprfont, enhancing its role to convey emotions.
I have had some fun trying two different systems against each other: the Eximus DP-1 dac/amp combo alone, versus the Audio-gd 9.2 + Burson HA-160 amp. The first one costs around 3000$, the second combo (with VH Audio cables) would be around 2400$.
While the level of resolution is in a similar scale, the Eximus had tighter bass (with much better definition) and treble refinement. Also the sense of coherence in the music was better.
The sense of blurriness in the bass, though, is given by the Burson amplifier. Ruling it out, and using the NFB-9.2 through Eximus DAC, the difference in bass reproduction becomes much smaller, with close degree of definition and precision. The Audio-gd flavour comes out as flatter and more transparent than using Burson amplifier, with (comparatively to the Eximus) more energy in the upper register.
If I had to make the differences between the two sources, using the same Eximus amp (with its own character of being delicate, transparent, smooth and refined) larger than they are, stretching them, I would trace two distinct profiles, where the Eximus has the capability to render notes with a deep, intense colour, giving headphone listening a focused, romantic listening.
The Audio-gd NFB-9.2's puts its strength on a balance of neutral timbre, bass weight, large sense of space, underlining certain trebly effects, while offering a believable, correct midrange reproduction. Such midrange trait is confirmed by listening to AKG K501, one of the few headphones I have heard which reproduces midrange correctly, which sounds sweet with the Audio-gd even if its mids aren't forward sounding like happens on sources like Bitstream.
Among the headphones I could test, I especially liked AKG K501 with the Audio-gd. Apuresound ER4P were also a good pairing. With ER4S (and HF5 with PtoS adapter) there was a bit too much crispiness in the upper treble region and microdetail retrieval.
The Audio-gd is very pleasing with headphones having good midrange reproduction, being them correct reproducing ones (AKG K501, or Sennheiser HD600... or Stax SR-X Mk3 Pro and SR-003, for that matter), or forward sounding ones (my bias: Etymotic variants, Grado's), and I'd be also curious to use it with HD650, which sounded great with Eximus when I could try the combo in a shop.I feel that, out of all my three sources (NFB-9.2, Eximus DP-1, Halide DAC HD), the NFB-9.2 is probably the best match for my Audio Technica AD2000: The AD2000 has very prominent midrange, often crossing the border of being peaky in the upper midrange / lower treble. Such exaggerated frequency response also makes the bass sound leaner than it actually is. The pairing takes the advantage offered by the Audio-gd DAC's bass weight, expansive sound and flat midrange, which basically enhances all the sonic characteristics of the AD2000. I would strongly advise towards this combo, especially for Audio Technica lovers.
As far as amps go, I'd use either a very smooth and transparent solid-state amplifier (being it, as an example, the amp section in Eximus DP-1), or neutral tube amplifier. The Burson amp gives some justice to the NFB-9.2 DAC already, but the dac can scale much more.
Other thougths (mostly USB related):
Using it through USB, I have noticed that, at times, my computer needs to be rebooted, otherwise Foobar2000 would start producing glitches when reproducing the music. The same doesn't occur when using other digital inputs. I have noticed, that artifacts happened more when my Laptop was "resurrected" from Hibernation state (basically, when Windows 7 freezes the session and the computer switches off).
I will have to try other USB cables at some point, and I am going to install the drivers (which can be found on Audio-gd website) on other USB ports as well.
I wish I had a Stello U3 at hand, to see how the Tenor Chip fares against high quality external converters. I'd be expecting much also from Art Veloce (as soon as it comes out), or the future 192 kHz version of Halide Bridge.
Thanks for reading,
Edited by antonyfirst - 6/12/12 at 4:44pm