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.

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Matrix Quattro Balanced Amplifier

After spending a lot of time with some high quality tube amplifiers, I thought it was time to revisit the world of solid state (using sound processing chips rather than tubes). Some headphones seem to pair well with tubes while others like solid state so it’s always nice to have both options available.

Matrix M-Stage (HPA-1): the Quattro's older sibling

Matrix M-Stage (HPA-1): the Quattro’s older sibling

The amp I decided on is the Matrix Quattro amplifier which offers balanced and unbalanced operation (which I’ll explain later) and pairs really nicely with the Matrix X-Sabre DAC I bought a little while ago. I was fortunate enough to also be able to buy a second hand Matrix M-Stage (HPA-1), the Quattro’s baby brother (although it’s been around longer). The M-Stage is renowned as a great bang-for-buck entry level amplifier (around $300) so how would the more expensive Quattro compare at its $450 level? Let’s find out…

Overview

The Quattro builds on the success of the famously affordable and excellent M-Stage amplifier, but brings improved design and balanced operation. It was the balanced operation that hooked me because I love the idea of it from my days working in car audio where I often designed systems with completely separate left and right channels, but let me explain the concept a bit better.

Every speaker (or driver in a headphone) requires a positive and negative connection or an active signal and a ground connection. In unbalanced systems, there are two active outputs that deliver the stereo signal  – one to each driver – and there is a single ground connection that is shared between both drivers. This setup can produce very, very good sound, but there is also the risk of the ground connections causing some leaking of sound between the left and right channels which can result in the sound becoming less defined and less controlled. I’m sure there are much better explanations of these circuits out there if you’re interested, but hopefully this paints enough of a picture to say that balanced circuits have the potential to provide cleaner, better defined sound.

Specifications

  • Max power:  1 W (balanced mode)
  • Power per impedance:  800mW @ 60 ohms / 400mW @ 300 ohms (balanced mode)
  • Inputs:  1 pair RCA, 1 pair balanced 3-pin XLR
  • Outputs:  2 x stereo 6.3mm headphone jacks / 1 pair balanced 6.3mm headphone jacks
  • Signal-to-noise ratio:  >98dB via XLR / >95dB via RCA
  • Distortion:  <0.001%

Just to explain some of these specs, the power of the Quattro in balanced mode is twice that of its unbalanced mode because it’s essentially 2 amplifiers working together when running balanced versus just a single amp when running unbalanced. Also, there is just one set of outputs that are used for both balanced and unbalanced operation, but I’ll explain that setup a little later.

The specs of the Quattro don’t really tell us a lot about its performance and there was nothing in that list which excited me more than any other amplifier on the market, but for the price and with its offering of balanced operation for my beloved T1 headphones, I had to give it a run.

Design & Compatibility

01170021The Quattro is a simple design that’s been described as two M-Stage amplifiers sandwiched together. That may or may not be true as there are definite similarities under the hood, but also some differences in terms of the components used.

Perhaps the most obvious differences are the combination of unbalanced and balanced circuits as well as the use of different op amps. Op amps are the chips that amplify the sound and lend the amplifier a significant dose of sound signature (how warm, cool, bright, dark, bassy, or tinny the amp sounds). Where the M-Stage uses the OPA2134 chip, the Quattro uses the OPA604 and OPA2604 chips for its balanced and unbalanced circuits respectively.

Inputs / Outputs

01170020The Quattro has a pair of RCA (unbalanced) inputs and a pair of 3-pin XLR (balanced) inputs. Unfortunately, it doesn’t get any line level outputs which is a shame. It’s always nice to have the option to use headphone amps as pre-amps or to have a straight pass-through to connect other amps in a chain, but for the average consumer who doesn’t stockpile audio gear, the Quattro offers everything you need in terms of these 2 input options.

For output of sound, the Quattro comes with a pair of 6.3mm sockets on the front which are labelled Solo 1 / Balanced R and Solo 2 / Balanced L. It’s only as I write this that I realise that the left socket is on the right side and vice versa!? Oh well, doesn’t really matter. The point is that this pair of sockets is multi-functional which is both good and bad.

The Good

01170018Having 2 jacks means that you can use 2 pairs of headphones simultaneously which is great if you’re comparing headphones or if you want to listen with a friend. It ‘s amazing how often I would like to be able to switch between headphones without having to plug and unplug leads all the time so the Quattro is great in that regard.

Neither good nor bad is the fact that the twin sockets are used for balanced output via normal stereo 6.3mm headphone jacks which are easy enough to buy from most electronics shops if you need to make an adapter. Please be aware though that you specifically need to use stereo jacks. Mono ones won’t work with the Quattro’s auto-detecting circuit which I’ll explain shortly.

The Bad

In my experience the twin 6.3mm arrangement is one of the least common ways to connect to a balanced output with 4-pin XLR being a much more common choice. That means you’re most likely going to need an adapter lead to connect your 4-pin terminated headphones to the Quattro’s 6.3mm sockets. It’s an easy DIY build if you can be bothered, but you can also buy this type of lead if you prefer so it’s not the end of the world, but an XLR socket would have been better I think.

The other thing I’m not a total fan of is the auto-detect circuit on the Quattro’s outputs. Although the concept of the amp switching modes for you is nice, the reality is that the process isn’t seamless and sometimes leaves me with a balanced connection to an unbalanced output. This is because the Quattro detects the status of the connection with the contacts on the 6.3mm plugs. It seems that sometimes, the plugs touch the wrong contacts on the way into the socket and make the amp think it’s connected to an unbalanced headphone. The only solution I’ve discovered is to unplug and reconnect the headphones or to switch the amp off and on again. It’s not the end of the world, but I would have been perfectly happy with a third button on the front panel to select my output type.

Other Design Elements

In terms of size, the Quattro is about twice the width of the M-Stage, but is shorter by about 15-20% and a hair lower in height. It’s a nice compact size.

On the front right of the unit is a nice large aluminium volume knob with a rough texture around the side. It looks good and feels good and it’s attached to a high quality Alps motorised volume pot so you can also use a remote control with the amp if you want. The remote is an optional extra, but it’s very well priced.

Also on the front panel are a power button and source button to switch between the RCA and XLR inputs. I was pleased to note that both inputs are able to provide output to balanced and unbalanced phones so you don’t have to use a balanced source to enjoy balanced ‘phones. Not only that, but the difference between the sound from the balanced / unbalanced input is near enough to identical that it makes no difference which you use.

01170017Finally, on the left side of the amp’s fascia are lights indicating mute status (only available using the optional remote control), input in use (RCA / XLR), and output status (balanced / unbalanced).

Compatibility

The Quattro’s power output means it will drive most headphones other than difficult-to-drive planar magnetics. I’m hoping to try it with some Audeze LCD 2s soon so I’ll update if there’s anything notable to share. Unfortunately, the Quattro has an output impedance of around 10 ohms which is quite high and may negatively affect the frequency response and tightness of sound from lower impedance headphones depending on their specific specs. Testing the Quattro with my 32 ohm headphones showed some variation compared to the M-Stage with its 5 ohm output, but it was very much a case-by-case thing. The one thing I can say for sure is that it will not match ideally with low impedance, multi-BA IEMs like the Miracles. The sound is really clean and hum is negligible, but the frequency response is altered slightly by the impedance mismatch.

Other than the minor issues with output impedance – and I do consider it minor because it’s an amp designed for desktop headphone listening, not IEMs and portables – the Quattro drives all my phones really nicely and I love the fact that it can run unbalanced / balanced in and unbalanced / balanced out. There’s plenty of versatility in how you use the amp and with what.

Sound

01170022Having been excited to buy the Quattro, I was initially disappointed with its sound. It was a bit harsh with the T1s and I felt like it wasn’t significantly better than the much cheaper M-Stage. The balanced output was definitely an improvement, but I was still left no really enjoying what I heard. Although I’m still quietly skeptical about the effects of burn-in, I decided to leave the Quattro running for a while to see if the sound changed at all. I didn’t listen to it during this time so I know I haven’t adjusted to its sound, but I can definitely confirm that I now thoroughly enjoy the sounds being produced by the Quattro in both unbalanced and balanced modes.

For the review of the sound, I’m referring to the character of the sound in both balanced and unbalanced mode. The balanced circuit is just 2 of the unbalanced circuits running in parallel so the character of the sound is identical. I’ll explain the audible impacts of balanced versus unbalanced output separately.

Treble

Treble from the Quattro is present and extended, but smooth. Even with the sometimes edgy Beyer T1s, the Quattro produces very listenable treble that’s easily on par with the treble produced by other amps in this price range or slightly above.

The Quattro produces brighter treble than the M-Stage, but manages to do so without getting cold or harsh. The treble can be a little dry, but the overall signature is slightly warm so it balances the treble nicely. Fans of sparkly treble may want to look elsewhere for an amplifier because there’s not a lot of sparkle in the Quattro’s sound, but don’t mistake that for a lack of treble or extension. The treble’s there, it’s just not enhanced or lively – instead it’s smooth and easy to listen to. To my ears, the Quattro strikes a really nice balance by presenting a sound that’s not as thick as the M-Stage (which is a great amp) while still keeping the smooth and musical presentation that makes the Matrix gear so enjoyable. I was really impressed with the Quattro’s rendition of the detail present in the sound of a solo violin during the listening I did for this review. The Quattro was able to accurately recreate the subtle rasp of the bow being drawn across the strings sounding completely accurate and lifelike. I think that’s a benefit of the slightly dry sound – it allows details like this to come through where a lusher, smoother sound might cover them over.

Mids

The Quattro’s midrange is accurate and clean. It’s got good presence in the overall presentation and strikes a nice balance between musicality and accuracy. Once again it’s drier and cooler sounding than the M-Stage, but still enjoyable and slightly smooth. I really like the presence of the midrange created by the Quattro. Even in busy, active tracks, the vocals are always clean and separate, but not enhanced or pushed in your face in any way. THey are slightly forward compared to the rest of the spectrum, but only to a degree that you notice if you’re listening for it.

Bass

The Quattro produces bass that is largely accurate, but possibly a bit behind the rest of the spectrum. I wouldn’t say it’s lean sounding at all, but the mids and treble overshadow the bass ever-so-slightly. The quality of the bass though is very good. There is texture and impact as well as body on sustained bass notes – it’s just that all of this happens slightly behind the rest of the spectrum. Extension of the bass is really good all the way down and is probably more balanced in the lower ranges than around the mid-bass.

It’s hard to be sure because of the time taken to switch, but I think bass impact and present improves slightly when running in balanced mode. This could simply be a reflection of the power output doubling and therefore having more energy to apply to bass notes.

The Quattro’s bass presentation pairs really nicely with bass-tilted phones like the Fischer FA-011 LEs and I imagine it would also really suit some of the Sennheiser models with a bit of extra mid-bass warmth.

Signature Summary

I don’t normally do this, but I wanted to clarify the descriptions I’ve provided of the bass, mids and treble. I found myself struggling to describe the Quattro’s sound in this review and I think it’s because the Quattro is largely neutral and accurate to the source with a slightly dry, but musical presentation. The comments above reflect very subtle impressions only and should not discourage anyone from considering this amp because it’s very, very good for its price and the evidence of that fact is the difficulty I had trying to really dissect its sound signature.

General Presentation and Staging

Matrix Quattro AmpIn unbalanced mode the Quattro produces a good-sized soundstage (or headstage) with decent width and depth, although I would say it is wider than it is deep. There’s not a lot of vertical layering or vertical space so the result is that all of the sound seems to be placed across a narrow stage extending side to side. The stage sounds open and in no way congested, but it’s not expansive and spacious like some amps I’ve heard, although those amps also cost significantly more (e.g. $200+ more). Staging is definitely more open and more accurate than the M-Stage so the Quattro is a definite upgrade.

Beware: moving to balanced mode makes a significant difference to the soundstage! Switching over to use the balanced outputs of the Quattro lifts the sound to a whole other level. The overall signature is unchanged, but staging resolution is dramatically increased. Everything becomes more sharply defined, gains extra presence and weight and just generally gets better. This is why you buy a Quattro!

In balanced mode the stage is deeper and taller while retaining the same side-to-side space. The accuracy of placement is improved and the ability to hear vertical layers in the sound is improved as well (i.e. vocals now sound higher than a guitar being played by the singer). In balanced mode, the Quattro’s stage and presentation is outstanding and highly enjoyable. It’s still not expansive and massive, but strikes a good balance by placing the listener “a few rows back” from the stage while keeping the music close enough to be engaging.

Summary

For its $450 price tag, the Quattro is definitely an amplifier worth considering if you’re running balanced headphones (or if you can get a cable to make them balanced).

I probably wouldn’t specifically recommend the Quattro if you’re only using unbalanced headphone connections even though it’s a good amplifier even in unbalanced mode. With the new M-Stage (HPA-2) out now, I would expect it to match the Quattro for unbalanced performance and you can always change op amps (see below) to upgrade the sound of either amp so I’d probably choose the M-Stage plus an upgraded op amp for unbalanced use, but it’s a no-brainer for balanced headphones – the Quattro is excellent!!

Just like its older brother, the original M-Stage, the Quattro offers outstanding value for money with good power, an enjoyable sound that’s more neutral and detailed than the older M-Stage, and the opportunity to wring every last bit of performance out of your headphones with balanced cables.

A Quick Note on Op Amps

01170024I’m new to op amps, but having come from recent experiments with tubes in amplifiers, I look at these little “chips” kind of like digital tubes. What I mean by that is that you can tweak the sound of your amplifier by using different op amps. In the image to the right, the op amps are the black, rectangular things – there are 4 along the top and one in the bottom left corner.

The Quattro uses a single, stereo op amp for unbalanced operation and uses 4 mono op amps for balanced operation. This can make it an expensive prospect to upgrade because you need to buy 5-6 op amps depending on the versions you use, but it can also provide some relatively cheap fun because you can pick up decent op amps from as little as $5-6. You can also spend up to nearly $100 each if you want to spend that much, but it’s not necessary. You do need to make sure the op amps you buy are suitable for your device, but it’s not too hard to work out with a bit of online reading and asking on forums.

I’ll be posting an article specifically on op amps soon so subscribe if you want to know more. I’ve ordered a bunch to plug into the Quattro and a couple of other amps I’ll be reviewing soon and I’ll have impressions of the different op amps and how they influence the Quattro, M-Stage and a Fiio E12DIY portable amp.