Tralucent DacAmp One

The DacAmp One is a new entry into the portable audio market from relative newcomer, Tralucent. Subscribers to this blog who’ve been with me for a while may have read my reviews (and ongoing praise) of Tralucent’s previous portable device, the T1 amplifier. That amp, despite it’s simplicity, has a certain magic in its ability to be warm, detailed and spacious all at the same time so I was interested to hear what Voodoo Tralucent managed this time around…

Overview

The DacAmp One is a portable USB DAC and headphone amp similar (in concept) to products like the Fiio E17 and JDS Labs C5D, however, at a price of approximately $500 the DacAmp One sets itself apart from these and places itself in a bit of a gap in the market occupied only by the Pico Headamp. There are more expensive DAC/amp combos from the likes of Cypher Labs and plenty of cheaper options like those already mentioned, but the $500 mark is less crowded (at least in the Australian market).

  • Inputs:  mini USB, optical, 3.5mm stereo line-in
  • Outputs:  3.5mm stereo line-out, 3.5mm headphone out
  • Battery life:  around 30 hours (depending on the load and volume used)
  • Sample rates:  16 & 24-bit up to 96kHz (same for USB and optical)
  • Compatible impedances:  8 – 300 ohms
  • Output power: 190mW (95mW per channel)
  • Dimensions:  60mm x 115mm x 24mm (W x L x D) – length includes volume knob of roughly 12mm

On paper, the DacAmp One appears capable. There are no features or specs that jump off the page at me, but as you may have experienced in your own purchases and auditions, there is far more to a product than its specs and features – implementation is everything!

Design and Features

So the DacAmp One doesn’t appear to offer any unique features, but how are those features combined into a single package for portable audio pleasure?

Form Factor

SAM_0184-2The DacAmp One (DAO) is presented in a similar case to the Tralucent T1 except that the DacAmp One is slightly larger. Surprisingly though it seems lighter. This may be that it’s lighter than you expect for the size or maybe it is lighter than the T1. Either way, what matters is that it’s light for its quality of build and finish.

The DAO is very nicely finished and shows significant development in Tralucent’s quality of finish since the early days of the T1. It’s still a simple aluminium case with aluminium end caps attached by screws, but the case is now stamped with the Tralucent logo and the end caps are really nicely moulded and printed. The small toggle switches look and feel like quality items and the unit has an overall feel of sturdy, but well-finished ruggedness.

On the front of the DAO (from left to right) is the gain switch (high / low), headphone out, line in, and volume knob. Everything is well spaced and the recessed sockets are large enough to allow for even large 3.5mm jack housings to fit with no problems at all.

Moving to the back of the DAO things get a little more complicated…

SAM_0188-6From left to right again we have the line in / optical in port (this is a clever, dual function port like the ones used in the AK100), the mini USB port used for charging and USB DAC duties, the mode indicator light (more on that shortly), the mode switch and the power switch.

All of this seems straight forward, but the functionality of the lights for the mode indicator took a few moments to get my head around. The mode switch selects between DAC mode (either optical or USB) when down and charging mode when up. What threw me initially is that the blue DAC indicator light comes on even if the unit is switched off. You still have to power on the unit to hear anything though whether using the onboard amp for headphones or using the line out to a different amplifier. In fact, the power switch has to be on for your computer to even “see” the DAO as a DAC device. The blue DAC indicator light might be on, but the DAC circuitry is only active when the power switch is on.

Battery Use & Charging

To be fair to the DAO I wanted to allow plenty of burn-in time before judging its sound quality. When I first received the unit I set it up with my computer and a pair of headphones to run as both DAC and amp over night and into the next day. What I didn’t know is that the DAO runs on battery power exclusively meaning that even as a DAC it will chew through your battery and not be charging at the same time. The charging circuit is completely disconnected when running in DAC mode. This could well have been a deliberate decision to prevent any USB noise creeping into the sound, but it’s a shame that you need to then charge the DAO before taking it portable.

For example, imagine you commute with the DAO as your portable amp. You arrive at the office, plug your DAO into your computer to improve your office-based auditory experiences and then want to unplug the DAO to once again use it as your amp on the way home again. At some point in this process (perhaps on day 2 or 3 of this cycle) you are going to have to go without the DAO while you charge it because (as far as I can tell) it’s not taking any charge while you’re using it as a DAC.

On a positive note, the charge time is only 1.5 hours so you could always just switch to charge mode each day on your lunch break and continually keep the DAO topped up, but I was slightly surprised that I couldn’t charge in any way during use. I did try charging while using only the amp stage, but heard all kinds of noise coming from the USB circuit.

Supplied Accessories

SAM_0161-1The DacAmp One is packaged almost identically to the T1 amplifier which is a good thing because that means you’re getting everything you could possibly need: some rubber feet, a hex key to open the case and install the battery, a nice quality interconnect cable, 2 Tralucent rubber bands, a USB cable, and an optical adapter to connect standard optical leads to the 3.5mm port. There’s nothing flash here, but there doesn’t need to be – everything is exactly what you need at a good quality level and you’re not paying an excess for things you don’t need.

DAC Performance

 To test the DAC of the DacAmp One completely isolated from its amplifier, I ran the DAO in DAC mode with the line-out running to my Bottlehead Mainline. The Mainline has 2 inputs that are switchable on the fly so I can directly compare the DAO line-out with other options like the vastly more expensive desktop X-Sabre DAC and the built-in DAC of the Fiio X5.

As you might expect, the DacAmp One doesn’t compete with the X-Sabre, but you might be surprised that it took me a couple of tracks to hear the difference! I recently bought “The Union” by Elton John & Leon Russell so I’m listening to that album as I write this review. Foobar is driving the X-Sabre via its ASIO drivers while MediaMonkey is driving the DAO via WASAPI. Both are running in exclusive mode for the purest possible audio path.

11010045I started with the very simple track, “Eight Hundred Dollar Shoes” which is quite reminiscent of Elton John’s own “Candle in the Wind” – simple, slow and thoughtful. On a simple, stripped-back track I was honestly having trouble telling which DAC was which and started to worry that my X-Sabre was not the excellent DAC I believed it to be, however moving on to the next track, “Hey Ahab”, I soon heard the difference. With the more complex and multi-layered arrangement of “Hey Ahab”, I soon heard the X-Sabre stretch its legs and create a sense of space and depth that the DacAmp One just couldn’t match. Don’t get me wrong, a portable DAC shouldn’t be able to match the abilities of a desktop DAC that costs 3x as much.

What really stood out in this first test is the wonderful tonality from the DacAmp One. It is very, very close to neutral, but with just a hint of smoothness. I won’t go so far as saying warmth because that may overstate the delicate touch of musicality from the DacAmp One. For my tastes, the DacAmp One nails the signature perfectly – there’s no in-your-face, bleeding edge push for details at the expense of enjoyment, but there’s still plenty of detail, it’s just not emphasised to try and “wow” you and that’s great because that sort of approach leads quickly to fatigue and harshness.

With the DAO stacking up so well in tonality, but falling behind in terms of layering and spaciousness compared to the X-Sabre, I thought it was probably time to create a level playing field by comparing apples with pears as it were. If the DAO is a metaphorical apple and the X-Sabre is a metaphorical banana, the Fiio X5 is more like the DacAmp One and is my metaphorical pear in this comparison.

I struck a small quandary when comparing the DacAmp One and X5 because I didn’t have matching source cables. I’m using some nice Neotech RCA cables for the DAO, but had to handicap (out of necessity, not choice) the X5 with a decent quality 3.5mm to RCA cable I made myself, but it’s slightly inferior to the Neotech RCAs.

Predictably, the sound from the DAO reflected the improved cables with slightly better treble detail and sparkle, however, the X5 showed a clear edge once again in the sense of depth and layering created. To my ears, the DacAmp One DAC creates a stage that’s a bit flat. It’s as though spatial cues are not rendered as well in the DAO DAC as they are in some of the alternatives. There’s no doubt that the tonality and accuracy is exceptional across all frequencies, but the space and layering cues fall a little behind what I would like to hear from a $500 unit.

Amp Performance

The LED on the DacAmp One is not as blindingly bright as this image makes it look - gone are the days of lighting your bedroom at night with a Tralucent T1 on your bedside table

The LED on the DacAmp One is not as blindingly bright as this image makes it look – gone are the days of lighting your bedroom at night with a Tralucent amp on your bedside table

DacAmp One is a combined device – DAC and amp – so it’s important that you don’t make your decision based only on the DAC stage (unless that’s the only reason you’re considering buying it of course, but then I would suggest you should consider a dedicated DAC rather than any of the 2-in-1 options out there).

To isolate the amp stage in the DacAmp One I am using the X5 as my DAC (driven by MediaMonkey on my PC) and feeding the DacAmp One via the Fiio L16 high quality interconnect.

Similar to the DAC stage in the DAO, the amp stage is very clean with no significant emphasis on any frequencies, proving itself as an accurate, neutral and well-balanced device in all regards. Interestingly though, the amp stage presentation and staging is very similar to the DAC’s meaning that the soundstage is quite small and intimate with not a lot of layering and depth to speak of. I wouldn’t call it congested because there is good separation between each instrument and voice, but it all happens in quite a limited space that’s fairly heavily centred in the stage.

In comparison to the DAO, the X5’s onboard amp (still using the X5 as a DAC from the PC) is noticeably more open sounding and has slightly more treble energy (this is neither good or bad – just different and provided purely as an observation). Although I consider the X5’s onboard amp to be adequate, I don’t rate it as exceptional in comparison to dedicated offerings like Fiio’s own (and extraordinary) E12DIY. In other words, to my ears, the staging and presentation from the DacAmp One falls a bit short of my expectations from a $500 amp / DAC combo. As I hear it, it is bested by an all-in-one digital audio player that costs less and does more (i.e. stores your music in addition to decoding and amplifying).

DacAmp One with Various ‘Phones

Unique Melody Miracles

The DacAmp One is nicely powered for sensitive IEMs and provides plenty of range on the volume control in low gain mode. That’s often a challenge for portable amps that aim to drive both IEMs and full-size headphones so this is a big win for the DacAmp One.

Beyerdynamic DT1350

On low gain mode, the DacAmp One comfortably drives the DT1350s with plenty of play in the volume control so this it likely a good indication of how it will perform with many of the popular portable headphones on the market. Even in low gain mode you’ll have ample power for the majority of portable headphones.

Fischer Audio FA-011 Limited Edition

The Fischers are a relatively sensitive (98dB) headphone with moderate impedance (150 ohm) and once again are comfortably handled by the DAO even on low gain mode. In fact, it’s worth noting that this seems to be the sweet spot for the DacAmp One. While the X5’s onboard amp runs out of puff with the Fischers, the DAO seems to thrive. The sound is full, punchy and detailed with plenty of range still available on the volume control. The presentation is still a little flat, but the sound itself is wonderfully balanced across the full spectrum from bass to treble whereas the X5 starts to lack bass and volume output in low gain mode with the Fischers.

From here things get a little more interesting…

In theory, the DacAmp One should be able to drive the Audeze LCD 2s which need only 40mW to achieve 110dB (remembering that the DAO can supply 95mW per channel), but the LCD 2s pull quite a lot of current (up to 24mA for a 110dB peak). Most of my listening occurs at around 80dB which should be no problems so how will the DAO handle the LCD 2s at my normal listening volumes?

Audeze LCD 2

The LCD 2 pushes the limits of the low gain setting on the DacAmp One and had me second guessing whether to switch up to high gain or stick with low gain. To my ears, the sound is a bit compressed in high gain mode compared to low gain mode so I chose to stick with low gain using about 80-85% of the available volume to achieve perfect listening levels for my tastes. The good news is the LCD 2s were perfectly enjoyable from the DAO. I wouldn’t choose it over a dedicated desktop amp for the LCDs, but for portable use it’s definitely up to the task.

I didn’t bother trying the DAO extensively with the Beyerdynamic T1s because the DAO is rated up to 300 ohms. I’m not sure if that should actually prevent it from comfortably driving the T1s, but a brief listen proved to be easily acceptable (low gain mode onace again) even if the electronics of the DacAmp One aren’t specifically rated for a 600 ohm load like the T1s. It’s possible that the sound was a bit light in the bass, but I find that to be the case with most portable devices trying to drive the T1s.

Summary

I really like Tralucent as a brand and still don’t hesitate to recommend the T1 amplifier as a great option for a reasonably priced portable amplifier so I really wanted to love the DacAmp One. As it is though I’m left a little underwhelmed. It’s a nice looking and feeling product with outstanding plug-and-play compatibility, exceptional neutrality and good range in being able to drive everything from IEMs to full-size headphones with a definite sweet spot on higher impedance headphones, but it doesn’t quite reach that final 5% that takes good sound to great sound – namely the subtle spatial cues, textures and layering that leave you thinking “wow” every now and then. If it were priced a bit lower, I might feel differently, but for $500 I have a hard time identifying who this product is for and would likely recommend alternatives like the X5 as being more versatile (it’s a DAP in addition to amp and DAC), better sounding and cheaper.

Fiio X5 Portable Hi-Res Music Player

Fiio’s latest contribution to the world of sound and music came in the form of the X5 portable music player. Following on from the recent release of their limited edition portable amplifier, the E12DIY, the X5 is another statement from Fiio that they want to play at the high end of sound quality, even if the pricing is still only at the mid level (and for that we are thankful!)

Overview

  • Size:  67.6 x 114 x 15.6 mm
  • Weight:  195 g
  • Storage:  2 x micro SD (TF) card slots – max capacity 256Gb at time of launch
  • Line-out:  1.5 Vrms
  • Output impedance:  <0.26 ohms
  • Recommended headphone impedance:  16 – 300 ohms
  • Max output current:  >150 mA
  • Max output voltage:  8 V (peak-to-peak)
  • Battery life:  > 10 hours
  • Sample rates:  up to 192 kHz / 24 bit

There are plenty more specs available on the Fiio website (fiio.com.cn), but to me these are the key elements that show the general versatility of the X5. There are some further outstanding numbers such as crosstalk and signal-to-noise ratio, but there are different figures for the amped headphone out and the unamped line-out so I’ll let you look these up yourself to as not to overload everyone with numbers.

The X5 retails for around $400 and offers the same compatibility as other much more expensive players. However the question is whether it offers the same performance? I bought the X5 to replace my far more expensive RWAK100 so outstanding performance was a must and I haven’t been disappointed… for the most part.

To read the rest of the review, please head over to the new Passion for Sound site. It’s sexier and there’s plenty of great new content coming soon, but only on the new site. Hope to see you there!

 

Matrix X-Sabre DAC

Matrix is a Chinese brand that made its name with the astonishingly affordable and excellent M-Stage headphone amplifier. After making a few products which were seen as “clones” of other brands’ offerings it seems Matrix wanted to make the point that they create great products in their own right, not just copies of other people’s gear. The X-Sabre is where they make their stand.

Overview

The X-Sabre is a flagship, dedicated DAC built around the insanely popular ES9018 SABRE DAC chip which also lends the “Sabre” moniker to the product. The X-Sabre has no amp or pre-amp just turns data into audio signal – nothing else. At a retail price of around AUD $1300 it’s pricey, but is it worth the dollars?

  • Inputs:  Coaxial, AES, USB (no optical)
  • Sample rates:  44.1 kHz – 192 kHz (Coaxial and AES), up to 384 kHz (DXD) or 5.6448 MHz (DSD) via USB
  • Outputs:  RCA / XLR (balanced)
  • Output Voltages:  2.2Vrms (RCA) / 6.8Vrms (XLR)

To read this full review, please head over to the new Passion for Sound site. It’s sexier and there’s lots of great new content.

 

Chord SilverPlus USB Cable

I need to start this review with a strong disclaimer.

Having read a lot of different views and applied my own limited knowledge to the topic, I really didn’t expect an “upgraded” USB cable to have any impact on the sound output by a DAC. According to much of what I’d read, the USB data stream is checked at both ends so data can’t be lost or added. I don’t know if that’s accurate and I’m not about to get into the science of digital audio. The reason I’m sharing this is because people often read cable reviews and cry “placebo!” so it’s important that you understand my expectations going in – I expected nothing and, therefore, the placebo effect would produce nothing.

Introduction

Head-Fi0040This all began when I was shown a group test conducted by Hi-Fi News (UK) in which they compared a bunch of USB cables of different values using a combination of blind testing and objective data. It’s in their July 2013 magazine, but I couldn’t find it online at all. The review included reviews of cables ranging from 18 – 139 pounds and found a wide range of performance that didn’t always reflect the price of the cable.

It just so happened that the top rated cable in the “reasonably priced” bracket was available at one of my local stores, The Noisy Motel. I decided that I would enjoy a nicer looking and feeling cable if nothing else so I spent $75 expecting a cosmetic upgrade and with an open mind to the chance of improved audio, but no expectations. The results surprised me!

Cable Design

Having bought the Chord SilverPlus mostly as an upgrade in look and feel, I really liked the design. It’s not flashy, but it looks and feels solid.

Head-Fi0042The insulation is a flexible white plastic material which is soft to touch and looks neat and clean. The plugs on the cable are finished in a slightly textured white plastic with aqua coloured inserts. Finally, the contacts are all gold plated with white plastic inserts.

All-in-all the cable looks and feels nice, but not crazy expensive or extravagant.

On the inside (according to the available information) is a series of heavily silver-plated copper conductors insulated in a high frequency shield and then insulated by gas foamed polyethelene. I’d explain what that means, but I have no idea myself! The part I do understand is the silver-plated copper so I can briefly discuss the fact that I generally shy away from plated cables in analogue interconnects because I find the plating actually interferes with the coherence of the sound so I was slightly worried that the SilverPlus was either going to do nothing for the sound or actually disappoint me rather than impress me.

Results – The Sound

I was completely amazed when I connected the SilverPlus to my Vaio laptop and then to my Audio-gd NFB-5.2. The sound completely changed for the better!

I completed a comparison test using the Beyerdynamic T1s connected directly to the headphone output of the NFB-5.2. There are 2 key features of the T1 sound that are key to this review:

  1. They are amazingly resolving of textures and fine detail in the recordings
  2. They can sound harsh with certain sources (and to me the NFB-5.2 has a slightly brash / harsh top-end)

Head-Fi0041It was a pretty simple comparison using a generic USB cable which was probably supplied with a printer and the Chord SilverPlus USB. Very simply, I played a track via the generic cable (Michael Jackson’s “Man in the Mirror” 24-bit / 192kHz) and then the same track via the SilverPlus with no change to volume and using the same USB socket.

With the generic cable the sound was good, but the NFB-5.2 did have a little harshness in the top-end. When I changed over to the SilverPlus I started to notice some really interesting things. My first impression was that the midrange was pulled back ever-so-slightly. What I noticed next was that details in the higher frequencies became more prominent and yet in now way “in-my-face”. It was like there was more detail, but it was also smoother at the same time.

I also felt like there was more “space” in the recording when played via the Chord USB. There seemed to be better definition of the placement of each instrument and a clearer boundary or space between each distinct sound.

I believe the sensation of reduced mid-range was actually that the Chord cable did a better job of delivering balanced energy across the whole frequency range. As the track continued, the vocals and mids were clear and present and there was plenty of texture and detail, but it was in perfect balance with the treble and bass.

Overall, the addition of the Chord SilverPlus made the sound from the NFB-5.2 / Beyerdynamic T1 combo smooth, balanced and yet incredibly detailed. It revealed extra sounds and details in the recording that I simply didn’t hear on with the generic cable. For $75 – $130 (depending on cable length) the Chord SilverPlus is actually a really worthwhile upgrade to a computer audio system. I’m surprised to be saying that, but it’s true!

Final Point

The cable pictured here is the 75cm version. Be aware that 75cm is not as long as you might think. It’s worth going to the 1.5m cable if you want some flexibility in your setup. The 75cm version requires your computer to be pretty close to the DAC and won’t allow for a lot of play. If you’re like me and use a laptop (and rearrange your desk from time-to-time or move your laptop and DAC to other rooms for various reasons), the 1.5m cable provides plenty of flexibility while still being short enough to not have heaps of slack in a desktop setup.

Audioquest DragonFly

If you’re like me and primarily use a laptop computer, you’ll know the trials of extracting great sound from your computer. In my case, the onboard sound is actually quite good, but it’s not exceptional and I like exceptional.

At home, the sound processing is handled by my Audio-gd NFB-5.2. On the road I used to use the Creative X-Fi HD USB, but as good as the X-Fi is, I had a couple of needs that it couldn’t quite meet. Firstly, it required a separate lead to connect so I ended up with boxes and cables everywhere. Secondly, it struggled to effectively drive my low-impedance IEMs like the Shure SE535 LEs and now my Unique Melody Miracles (review coming soon).

After much hunting, I finally found a DAC that I thought would meet all my needs. Does it? Read on to find out…

Overview

The DragonFly is a DAC and headphone amp created in the form factor of a full-size USB thumb drive. That means it is about 3-4cm long, around 1cm thick, and about 1.5cm wide. At that size I wouldn’t have expected particularly strong performance, but other reviews I read suggested otherwise.

The DF’s general specs are very competitive:

  • Sample rates:  44.1kHz – 96kHz
  • Minimum HP impedance:  12 ohms
  • Maximum power:  150mW

I was excited to see the 12 ohm minimum rating for the headphone impedance as it suggested that my 15.9 ohm UM Miracles would pair well with the Dragonfly. We’ll get to that shortly…

Design

DF with lightThe design of the DragonFly is simply brilliant. It’s tiny, requires no USB cables, feels solid and high quality, and works flawlessly in general terms. I was particularly pleased to note that it’s small enough to not obscure adjacent USB ports.The chassis of the dragonfly is coated in a nice soft-touch black paint and overall it feels very high quality.

A fun (and useful) feature of the DragonFly is its LED indicator light. The indicator lights up in different colours depending on the status of the sound feed and the sample rate being used. It’s red when there is no activity and then turns to green (44.1kHz), blue (48kHz), Yellow (88.2kHz), or magenta (96kHz). It’s kind of fun to see the light change between different tracks at different sample rates and it’s useful to see if your settings are correct (i.e. if you play a high sample rate track and the light stays green, you know you’re settings are causing the system to down-sample your music).

If I had to find one fault with the design of the DragonFly it’d be the separate cap. So far I’ve kept hold of it, but I can see it being lost far too easily and wonder if it would have been possible to have it somehow stay attached to the body of the DragonFly (e.g. with a short string so it hangs free when not in use, but doesn’t get lost). It’s a tiny gripe, but it would prevent having to be quite so careful to place the cap in the bag every time I uncork the DAC.

Functionality

The DragonFly works without any special drivers which is a nice plus in my eyes. I’ve tried it with ASIO4ALL and with WASAPI and it works perfectly with both. I’ve settled on WASAPI because it’s easier in my setup, but there is no significant difference I could find between the 2. Regardless of the output drivers, the DF also handles all supported sample rates equally well with no hiccups.

DF PackagingAnother nice piece of functionality with the DF is that it’s happy driving moderate impedance IEMs like the Re272s and V-Sonic GR07s as well as high impedance cans like the HD650s, but it can also be paired with a separate amp using the DF’s 3.5mm jack as a line-out. To do this, Audioquest recommend turning the computer / DF volume to full, but I’ve found it can be used perfectly well as a variable line-out.

When pairing with amplifiers like the Tralucent T1, which has very high gain, the variable output of the DF is a godsend. You can reign in the volume on the DF so you can use a better range of attenuation on the amplifier’s volume pot.

In terms of functionality, there’s really nothing lacking in the DragonFly – it does what it does flawlessly in terms of straight-forward functionality.

Sound Quality

Where the rubber meets the road… a DAC and amp is only ever as good as it sounds and the DragonFly sounds very good, but perhaps not as exceptional as I’d hoped. I think my expectations were a touch unfair though so read on and I’ll explain in full.

In terms of basic sound quality, the DragonFly is excellent. It creates plenty of space in the soundstage, good placement of the sound image and nice response across all frequencies without any hint of colouration.

I’ve tested it with a number of devices including:

  • IEMs ranging from 15.9 ohms to 50 ohms
  • Headphones ranging from 32 ohms to 300 ohms
  • Active speakers
  • Portable amplifier

In all but one case, the DragonFly sounded great. Perhaps not quite as good as the Audio-gd NFB-5.2, but that’s to be expected when comparing a USB powered device to a mains powered device.

Line-Out Performance

The DragonFly works extremely well as a simple DAC with line-out. The sound provided to active speakers or a separate amplifier is clean, spacious and sweet. Being able to use the computer’s volume control as a variable line-out is a definite bonus too.

Headphone Performance

The output power of the DragonFly is simply amazing! The Creative X-Fi HD USB was just able to drive the 75 ohm Utrasone HFI-680s to a good listening level, but was underwhelming with the Sennheiser HD650s. The DragonFly manages to drive the HD650s to full listening volumes while still having plenty of room to spare in the volume adjustment range.

Of course, it doesn’t have quite the dynamics of a mains powered desktop amp, but you can’t expect that from USB power. As it stands, it’s the best USB powered device I’ve heard when driving power-hungry headphones.

IEM Performance

If you thought there was a “but” coming, you’re unfortunately right. The DragonFly maintains sweet sound on the 20 ohm Re272s and 50 ohm GR07s, but sounds a bit harsh with the 15.9 ohm Unique Melody Miracles.

DF BoxI expected better performance at low impedance due to the 12 ohm minimum rating published on the DragonFly’s box, but while it probably can handle 12 ohms, it won’t be with optimum sound quality.

I found a massive jump in sound quality by feeding the DragonFly’s line-out into the Tralucent T1 amp* before passing it onto the Miracles. You’d expect some improvement with a dedicated amplifier, but this jump was too great to be the amp’s prowess alone. To my ears, the DragonFly just doesn’t pair well with loads below about 20 ohms. That’s a shame to be sure, but given the distinct lack of a USB DAC/amp with 16 ohm prowess (from what I’ve seen and heard so far), I have resigned myself to using the DragonFly with the T1 if I want to listen to the Miracles from my laptop. For everything else, a direct connection to the DragonFly provides outstanding quality sound for a USB device.

* Obviously, the power of an amplifier isn’t required for low impedance IEMs like the Miracles, but a good amplifier will offer better control over the transducers in a low impedance IEM setup and will therefore provide better, smoother sound.

Interestingly, measurements conducted by Stereophile.com show the DragonFly has very low output impedance (around 0.65 ohms) which would normally indicate a good match with devices in the 16 ohm range so I am not entirely sure why the DragonFly doesn’t excel with the Miracles.

Summary

All-in-all the DragonFly is a brilliant piece of kit. For it’s size it is unbelievably powerful and sounds fantastic. It offers all of the processing features of more expensive desktop DACs (except support for 192kHz sample rates which few if any USB devices offer) at a relatively low price and with incredible portability.

At around $200-250 depending on your location, the DragonFly is fantastic value and its portability and compact design make it a winner in my book. It won’t outperform top-end DACs or separate, dedicated amps, but it’s the combination of size, functionality and very good performance that makes this a worthwhile purchase.

Perhaps don’t buy it to directly drive low impedance IEMs, but do buy it to connect to higher impedance ear / headphones, active speakers, and amplifiers.

Audio-gd NFB-5.2 DAC/Amp

For a while now I’ve been using a Creative X-Fi USB soundcard as my quality DAC and amplifier and it’s done an amazing job, but as a USB-powered amp, it was never going to shine with any truly high quality headphones. And so it came to pass that I decided on my first step into the realm of dedicated headphone amplifiers – the Audio-gd NFB-5.2

I decided on the NFB-5.2 because it is a combination digital-to-analogue converter (DAC) and headphone amplifier. Reviews I read seemed good and it was available from the great crew at Addicted to Audio where I buy a bunch of my stuff (often with their wise advice).

Specifications

Signal to noise ratio:  119dB
Output power:  3500mW @ 25 ohm – 150mW @ 600 ohm
Output impedance:  2 ohm (headphone out)
Sampling support: 44.1kHz – 192kHz (16-bit or 24-bit)
Inputs:  Optical, Coaxial, USB

I’ll review the NFB-5.2 in 3 stages: first a quick overview, then the DAC, and then the amp.

Overview

The front panel of the Audio-gd NFB-5.2The NFB-5.2 is quite simple and that’s good. On the front of the unit is:

  • A power button (left)
  • Volume control (right)
  • 6mm stereo headphone socket with a securing system to keep the plug in place
  • Simple, 4 character, blue display
  • 4 control switches (under the display)

All of the buttons and the volume knob are brushed metal and the case of the unit is also all metal. It’s not super heavy, but seems very well built.

The 4 buttons under the display allow you to select different options.

Button 1: Filter

The “Filter” button lets you select from a number of filters used to remove unnecessary frequencies from the DAC output. It’s generally not something that you’ll notice in the sound and is used more to remove subtle digital artefacts and noise from the signal. I played around a bit and now leave my NFB-5.2 set to filter #6 which has creates an output that looks like this:

A graph showing the effect of filter #6

Filter #6 frequency response chart

As you can see, it only starts to affect the sound at around 20kHz and above – all frequencies which are beyond normal human hearing limits, but it should help to clean up the overall signal.

There’s a full listing of the possible filter options here.

Button 2: DAC/HP

This button has 4 options. Options 1 & 2 activate the headphone amplifier output either without (option 1) or with (option 2) the OP amp. Options 3 & 4 activate the RCA line outs on the back of the NFB-5.2 and allow you to use it as just a DAC with a separate dedicated amplifier. Once again the two options are for the OP amp being used or not used.

The OP Amp

The OP amp (OPA) is modular circuit that can colour the sound to suit individual tastes. Audio-gd supply the NFB-5.2 with their OPA-2134 model, but you can buy 3 different options as aftermarket (or custom) options. The 3 other OPAs offer neutral sound, warm sound, or dynamic sound. I hope to review the OPAs separately in the future.

In relation to the OPA-2134 that comes standard, my feeling is that it’s better left switched off. Engaging the OPA using setting 2 or 4 of the DAC/HP switch results in a flatter sound with less depth and a weaker sound stage. There’s really no improvement that I can discern.

Button 3: Gain

A very simple option here: “high” or “low”. The “high” option apparently adds a 12dB boost across the range (from the DAC, not the amp). When I’ve used high gain, the sound seems to become a bit edgy when compared to the equivalent volume on low gain. I’m sticking to the low gain option, but others might like the extra energy delivered by the high gain.

Button 4: Input

3 options here: USB, Optical or Coaxial. Very simple.

All work the same although I have read claims of slight sound variations between the 3 inputs. As I don’t have a source with all three outputs I can’t do a fair comparison.

NFB-5.2 DAC Stage

The DAC in the NFB-5.2 is really nice. I’ve run my Bang & Olufsen BeoLab 3 speakers using the line out of the NFB-5.2 and the sound is beautifully clean, well-layered with plenty of separation between instruments and creates a stunning sound stage through the BeoLab 3’s acoustic lenses.

As I’ve already explained, the filter system is a nice feature for those who are more technically inclined, but once it’s set you’ll probably not think about it ever again so essentially the NFB-5.2 DAC stage is a set-and-forget affair and it does a fine job.

The TE8802 Chip

The NFB-5.2 is an upgraded version of the NFB-5. The only difference (according to what I’ve read) is the inclusion of the TE8802 USB chip. The TE8802 allows for asynchronous transfer… yeah, I didn’t understand either!

What all this really means is that the NFB-5.2 should be less susceptible to minor issues with errors created by the USB chip in your computer slowing down or running inconsistently. In short, it’s a minor upgrade that’s nice to have, but likely won’t be a game changer.

Compatibility

The NFB-5.2 worked perfectly with my laptop running Windows 7 (64-bit) and MediaMonkey as my media player. The Audio-gd drivers, combined with the TE8802 chip allow the NFB-5.2 to work all the way up to 192kHz/24-bit. After doing some reading, I believe there’s no real benefit (and possibly some disadvantages) to using 192kHz output sampling so after testing that it worked, I reverted to 96kHz sound and it’s brilliant!

It’s worth noting that ASIO drivers seem to give the best sound and best compatibility with the NFB-5.2. I started out using WASAPI drivers, but they created some nasty cracks and pops from the computer (not the NFB-5.2’s error) and the sound seemed better when using ASIO.

NFB-5.2 Amp Stage

The amplifier in the NFB-5.2 is probably slightly weaker than the DAC. Where the DAC seems to be beautifully clean and crisp, the amp strikes me as just a touch soft around the edges. Perhaps it’s just a warm sound signature when I prefer a more analytical sound in general. There is also a hum that’s audible through my Shure SE535 LE in-ear monitors, but read on because that’s not necessarily a bad sign.

Power

The NFB-5.2 has plenty of grunt. I’ve just received my new Sennheiser HD650s (thanks Gavin!!) and the NFB-5.2 volume control only just clears 50% (on low gain) to drive the 300ohm HD650s. There are very few (if any) conventional headphones that the NFB-5.2 couldn’t drive. Obviously there will be much more expensive amps that will sound better, but it’s got the power.

Noise

This is a tricky one. With the 300ohm HD650s, the NFB-5.2 sounds pitch black – no noticeable noise. On more sensitive cans like the Audio Technica AD900s, there is some hiss when you turn the volume right up (>75%), but none at normal listening volumes. From this perspective, the NFB-5.2 is nice and clean.

What put me off slightly here is the noise I heard when I connected my Shure SE535 LEs. The Shures are hyper sensitive (119dB SPL/mW) and this showed up a background hum from the amplifier. The NFB-5.2 is listed with a 119dB signal to noise ratio so there’s a good chance the SE535 is picking up the end of the NFB-5.2’s quality control limits and that’s OK – it’s not meant for driving hyper-sensitive IEMs. The main reason for my concern was that the hum isn’t balanced – it is louder in the left channel. That might not mean anything, but I look forward to testing the SE535s on another NFB-5.2 next time I visit Addicted to Audio. Maybe the right channel on my unit is just slightly cleaner than Audio-gd’s quality control standards, but I’m keen to make sure there’s not an error somewhere in the circuitry of my amp.

NOTE: It’s important to note again here that an amp like the NFB-5.2 is not really designed to drive super sensitive, low impedance monitors like the SE535s so this isn’t a major flaw, but until I can test a few other similar amps, the unbalanced hum leaves a tiny doubt in my mind.

Control

The NFB-5.2 amp is really well controlled. My Ultrasone HFI-680s can be quite bassy and that can cause them to lose clarity and control if not well driven. The NFB-5.2 does a great job of tightening the bass and keeping it punchy and full.

I mentioned earlier that the NFB-5.2 amp seems slightly soft around the edges and while that is definitely the case, there is no doubt that it does an amazing job for the cost. It’s an incredibly good amp for the cost (especially when you get a great DAC built-in).

Overall Conclusion

Would I buy the NFB-5.2 again if I had my time over?

Absolutely!!

For less than US$400 plus shipping costs (about AU$480 here in Australia) you get a really nice DAC with a solid, powerful amp that will drive anything very well. The amp may tend towards being slightly warm, but it reveals detail well and definitely won’t create fatiguing edginess in the sound. Being able to bypass the amp in the future while maintaining the really nice DAC stage of the NFB-5.2 is a massive bonus!

The high gain mode seems to bring some unwanted distortion or edginess to the sound, but there’s so much power on tap that you don’t need to use it if you don’t want to.

Of course, there’s also the fact that you can buy different OP amps for around $40 each and modify the sound to your tastes. I look forward to trying these out and sharing some thoughts in a future blog post.

If you’re looking for a nice entry point into DACs and amps, the NFB-5.2 is an excellent option – well priced, clean, powerful and simple to use – I’d recommend it.