INTRO
A few months ago I posted here asking if anyone knew of a decent cheap music server type device. I am still not over my old habit of using spinning discs for music playback, nor will I likely be over it soon. But I was wondering why nobody really makes a solid state music server device with a reasonable price tag. I don’t see why it should be so rare, especially considering what I am asking for; a simple playback device that uses a digital output to send audio out to an external DAC, and uses solid state storage for the audio files. That was all I really wanted, yet I couldn’t find anything to do it. The classic iRiver H-series players came close, but use hard disk drives instead of solid state. The HiFiMan HM-801 was on the right track, but I didn’t want to pay that much and really didn’t need the DAC/amp feature. I saw the QLS QA-550 talked about quite a bit, and I was interested, but didn’t think I wanted to deal with its limitation of only playing WAV files. And like the others, it was too small. I was looking for something to be used at home.
My search was futile because such a beast does not yet exist. But I did discover that QLS makes a higher model than the QA-550, oddly called the QA-350. It is similar but has more robust construction both inside and out, a built in rechargeable battery, and has a built in amp and DAC while retaining the digital outputs. The price is still very good at around $200 shipped. I decided I would give it a try. I realize that I discounted the HiFiMan unit because I didn’t need the extra DAC/amp, but really I just didn’t want to pay so much for them. I don’t mind having them on the QA-350 since the price is so low. Ultimately I would still have preferred a larger unit with a better display, but the price was right, and the portability of the QLS is starting to grow on me.
DESIGN
The QA-350 is actually quite versatile. It can be used as a transport. It can be a transport plus DAC, and you provide your own amp. Or it can be a full on system by itself, and you just plug your headphones in. On the other hand, it is not versatile when it comes to playback options: it plays 16-bit/44.1 kHz .WAV files only. No higher resolutions, no FLAC files, no mp3 files. It stores files on SD or SDHC cards, and supposedly accepts sizes up to 16GB. My largest card is 8GB so I can’t verify that but I have no reason to doubt it. I know there are larger cards out there but at the moment they are fairly expensive so I don’t see that as an issue. My 8GB card stores about a dozen full length albums, and I have a few smaller cards so realistically there is plenty of music for any given situation.
The QA-350 operates from a wall wart type power supply, and also has a rechargeable battery. It has a very small LCD display on top which can give you a tiny bit of info about what you are listening to. I say a tiny bit because it is limited in space so you only get the first few digits of the track title. Thus “Symphony No. 5 in D minor, Op. 47: Allegro Non Troppo” gets truncated to “Sympho1” or something like that. This makes it tough to know what you are listening to. On the upside, since you don’t have thousands of tracks available, it becomes relatively easy to remember what you put on your SD card. You can add all your files to the root directory and play them in linear order, or you can create sub-folders for each album or artist. The player will automatically start playing the first folder, then the second, etc, and basically function like a CD changer. The user can also manually jump from folder to folder if needed by using the up and down buttons. It is not nearly as complicated as it sounds, and you get used to it fairly quickly.
I’ve been in contact with Clark Chen from QLS Electronics to discuss the design of this unit. He says the QA-350 builds on the QA-550 by using a better PCB layout and power supply circuit. The QA-350 has a built in DAC featuring the Wolfson WM8740, and the headphone amp uses a MAX9722A from Maxim Integrated. I had never heard of this chip before. Clark advised that their amp section was designed with reference to the Sony PCM-D50 which is a $500 portable audio recorder and uses the same Maxim chip. The QA-350 runs at a slightly higher voltage, so the sound is similar but more powerful. I’ll have to take his word for it as I have not heard the D50 myself. You can check the QLS website for further specs. The general claim to fame is that the unit can produce an extremely high quality low jitter output to be sent to your external DAC, or you can use the high quality built in DAC and amp. It has no moving parts and is immune to vibration, which is often blamed for all sorts of sound quality issues. We’ll see how it lives up to those claims.
PACKAGE
The QA-350 comes in a small box which is stuffed full of accessories. The bundle includes the actual QA-350 unit, the external power supply, a separate charger for the battery, a 2GB SD card, a simple USB SD card reader, a 1/8th inch to RCA breakout cable, a remote control, a storage pouch, and finally the user manual. It is nice to see that they included everything you need in the bundle to get started. Granted most people likely have a few spare SD cards lying around, and a method for transferring to and from those cards, but if not QLS has you covered. Eventually you will want to add more SD cards to your library but the 2GB card will always be useful, and it holds roughly 3 CDs worth of music.
**Note this picture is missing the wall wart, which I was too lazy to unplug. It is also missing the SD reader, which was in the box and I forgot to take it out. Neither item is very exciting to look at so you are not missing much.
BUILD QUALITY
I think the QA-350 is primarily for home use, with the added bonus of portability when you need it. To that end it is built very well, with a robust aluminum case and even a wireless remote control. It has a dedicated coaxial digital output, a 1/8th inch headphone output, and a 1/8th inch combo output that acts as either a line out or a Toslink digital out. Use of a Toslink to 1/8th inch adapter is required to access Toslink function. I didn’t have one handy and wished one had been included. The transport control buttons, also aluminum, have a nice tactile feel to them, but the “play/pause” button on my unit requires a bit more pressure than it should. The other buttons feel nice. Headphone volume is controlled by an Alps pot connected to a smooth turning aluminum knob.
The entire unit is small enough to legitimately be called portable, although I certainly wouldn’t want to strap it to my arm for a workout. The main issue is not just size but weight; all that metal starts to add up. The weight is listed as .3kg, which converts to 300 grams. For some perspective, the Sansa Fuze weighs in at around 60 grams, first generation iPod Touch is 120 grams, the classic Creative ZVM was around 160 grams, and the big first gen iPod was 185 grams. The QA-350 should never be called light weight. Perhaps transportable is a better term than portable. To be fair, a direct comparison would involve a DAP/portable headphone amp combo, and in that case the QA-350 is not really that huge after all. Most DAP/amp combos would end up being at least the size/weight of the QA-350 anyway.
Battery life is sure to be another sticky point with some people. QLS rates it at 6 hours, and that is pretty much dead accurate with my testing. I was able to go as high as 7.5 hours on one occasion, but usually lost power before the 7 hour mark. It takes about 2 hours to fully recharge, and charging uses a separate power supply, which is also included. Thankfully you are not required to remove the battery to charge it; there is a separate plug for the charging cable which is distinct from the regular DC power supply slot. If you plug both in at the same time you can simultaneously listen off the PSU and charge the internal battery.
REVIEW GEAR
I used the QA-350 with a lot of different gear. It is easy to switch in and out of a system because it is so small. I tried it as a complete stand alone system, powering LiveWires Trips, Monster Turbine Pro Copper, Shure SE530, Ultimate Ears UE-Hybrid, AKG K702 and K240DF, and Sennheiser HD800. I used it as a player and DAC along with the Matrix M-Stage, Fournier HTA-1, Vivid Technologies V1, and DarkVoice 337SE. I used it as a transport feeding a Sigtone Shek D1 NOS DAC, a Musical Fidelity X-DAC v3 with X-PSU, and a Yulong D100 DAC. I compared it to a few of disc based transports including a Theta Miles, a Samsung BDP-1200, a Pioneer Elite DV-37, and a Lexicon RT-20. I also compared it to the Sansa Fuze as just a DAP, using no other components.
I burned in the unit for at least 100 hours, to make sure it was working properly. I didn’t notice any change in the sound, as I usually never do. All cables used were reasonable quality like Ethereal, Luminous Audio, Impact Acoustics SonicWave, and Blue Jeans.
MUSIC
I listened to all types of music, and I won’t bore you with the specifics. One unique issue this device has is that everything must be .WAV format. I tried a few things and ended up liking Winamp the best. It is very easy to convert most any file in your library to a .WAV file. I just made myself a “.WAV” folder and converted a ton of music to that location. Whenever I felt like switching music, I would load different songs on an SD card. One thing I discovered is that my converted music usually ended up with the track number at the beginning of the file name. I learned to go in and delete that so I wouldn’t waste precious display space with numbers. When I delete that, I can usually get enough of the title listed to figure out what I’m listening to.
Depending on how old the reader is, they may have never been around at a time where DAP storage space was at a high premium. I remember the days when we did what we could with a 128MB or 256MB player, and dreamed of having a few GB to play with. With the QA-350, you sort of return to that era. Not only are you limited in storage space, but .WAV files take a ton of room compared to MP3 or even FLAC. The result of this is that you end up spending a bit more time choosing what you want to listen to and transferring it to the SD cards. I found myself listening to a lot more complete albums rather than skipping around by genre or some other attribute. It almost brings me back to my vinyl spinning days. It certainly is less convenient than having 20GB or more at your fingertips, but there is also some sort of connection to the music that you get by focusing on what you want to listen to, and then sticking with it for a whole album. It’s a process that I found myself enjoying but certainly won’t be for everyone.
LISTENING
I figured I would start with the easiest part of the review, which was to use the QA-350 as an all in one unit. I’d load it with music, plug in some headphones, and see what it could do. I was pleasantly surprised with what I heard. The first thing I noticed is how smooth it sounds. I was using the Shure SE530 which I like a lot, but often can’t listen to for very long because they give me ear fatigue. That was not happening with this little silver box; I was an hour into it and still jamming away. I also noticed that it seemed to be more punchy and powerful sounding than the Sansa Fuze, even when played at similar volume levels. I love the Fuze but often I find myself cranking the volume very high to try and extract a bit more body or weight to the music. Eventually I get what I want but it comes at the expense of some sibilance on the top end and a bit of grain in the upper mids. The QA-350 avoids that and is so smooth that I generally listen a bit quieter than usual.
The QA-350 is able to easily power all of my IEMs. What’s more, it does so with zero background noise or hiss. It even powers the ultra sensitive LiveWires with virtually no hiss at all. It is among the quietest amps I own, yet is still fairly powerful. I was able to power most of my full sized headphones without much trouble. The Sennheiser HD800 had plenty of volume but was missing a bit of refinement and seemed a tad lean in the lower registers. The very difficult 600ohm AKG K240DF actually sounded very good but topped out just short of the full volume that I would like. It was suitable 90% of the time though.
To further describe the sound, I’d call it rich and smooth, with very good bass control. It is slightly tipped towards the warmer side of the spectrum, but is fairly balanced overall. Soundstage is suitably wide though not that deep, and imaging is fairly accurate. The bass is very tight and controlled but not as prominent as some other small amps I’ve used. This did not present a problem for me but would not be the best for trying to extract bass from something like an RE0 or ER4S. But again I did not have an issue with it at all. Even the K702 was able to be driven well, about on par with the amp section of the Audinst HUD-mx1. You don’t really notice the deficiencies unless you have a higher end amp on hand to directly compare. Eventually you will probably want to upgrade but this is a great starter amp, and could serve someone very well until they upgrade to a $200+ dedicated amp. Anything less than that would not be much of an improvement.
Moving on to external amps in order to test just the transport and DAC sections, I paired the QLS with a Vivid Technologies V1 portable amp. This gave me all the volume I could ever want but didn’t really sound any better than the built in amp, just different. The V1 is much more forward and aggressive while the QLS is laid back and polite by comparison. I was split down the middle as to which I would prefer; the V1 was better with the HD800 and the Monster Coppers, but the QLS was better with the K702 and much better with the SE530. The rest were just about equally enjoyable despite the different focus of the sound signature.
When I switched the V1 out for a higher end amp such as the Fournier HTA-1 or DarkVoice 337SE, I started to realize that the DAC section was responsible for the smooth sound signature, and the built in amp was just along for the ride. The QLS with its Wolfson WM8740 brought out the best characteristics of each amp I tried without really adding much flavor of its own. It is smooth and refined and has a very natural presence, with the same clean tight bass I had noticed earlier.
Since the QLS allows all of its outputs to be active at once, it is easy to compare it. The Matrix M-stage has 2 inputs with a selector switch on the front panel. I connected the QLS line out to input 1, while running a coaxial output from the QLS to an external DAC and then in to the M-Stage input 2. I could then play a song from the QLS and switch back and forth between the internal DAC and the outboard unit. The QLS could not compete with the Musical Fidelity X-DAC or the Yulong D100, but those are higher end units costing much more than the QLS. They just had more clarity and detail, with the Yulong D100 especially excelling at bringing out extreme realism. Once again the QLS DAC is not lacking until you critically compare it with something nicer. When comparing with the Shek D1 DAC (with re-clocking module and upgraded PSU), things are much closer. They share a similar smoothness of tone, with the D1 having slightly better depth to the low frequencies. The difference is not huge though, which is saying a lot since I paid almost $300 for the D1 a few years back. Both have a similar natural and musical sound, with good timing and detail, and both could almost be described as analog sounding. To me, analog sounding means that I get caught up in the music rather than focusing on details or flaws in the recording. This is a very impressive sounding DAC. How it ended up sounding very similar to a good NOS DAC I can not explain, but that’s what I’m hearing.
The trickiest part of this review for me is also probably the most important, which is dealing with the unit as purely a transport. I’m not sure if I am on board with the people who claim to hear massive changes when switching from one transport to the next. My experience is that when using a decent DAC, the transport has very little effect on things, within reason of course. I’m not discounting their performance altogether, and I’m pretty sure I have heard some problems in a system caused by a cheap poor performing transport. I simply feel that once you cross a certain threshold of quality, then there isn’t much more improvement to be gained. Another issue is that I own a lot of similar priced players, so perhaps that is influencing what I hear. I’ve read up on the subject and there are some compelling points on both sides so I’ll just keep my mouth shut.
That being said, I can simply say that the little QLS unit performed at least on the same level as some of my pretty expensive disc based transport units. My Pioneer Elite and Samsung units cost around $1,000 and the Theta and Lexicon cost a lot more. Yet when used as just a transport, none of them sounded any better than the QLS did. I thought the Lexicon had a slight edge over the rest, and felt that the Samsung was my least favorite by a very small margin, but I doubt I could single those issues out in a blind test. The QLS seemingly allowed me to tap in to the full potential of each DAC that I used, and scaled well as I moved up from cheap units to higher end units.
I’ve heard people compare the lower end QLS QA-550 to expensive transports such as the Opera Audio Droplet, Onix CD5SE, 47 Labs Flatfish, and find it on par or superior to all of them. These were also crazy DIY folks who were modding their 550s in various ways. It seems that some of the improvements they claimed from modding are already addressed with the 350, such as power supply (at least when run from the battery) but others I’m not so sure about: some people were tapping the I2S output directly and skipping SPDIF altogether, I’m not yet sure if this is possible or worth doing on the 350.
Your views on this ultimately depend on your feelings towards transports and how they supposedly sound. All I can say is that from my experience the QA-350 sounds excellent, and there is at least some theoretical basis for why that should be, mostly related to low jitter and low power supply noise.
Speaking of the power supply, there is one more thing worth mentioning: I found that the sound was slightly better when operating from battery power rather than from the wall wart. This was especially noticeable when using the amp feature and slightly less so when used as a DAC. Used as a transport, the difference was very minor but still appreciable. In all three scenarios, battery power seemed to give a bit more coherency and presence, and helped turn an already quiet background into pure blackness. All of my listening impressions that I mentioned above were achieved on battery power. Listening with the power supply was not terrible by any means, but perhaps 10 to 15% worse sounding. I noticed it most when listening to complex dynamic passages in music, or when cranking the volume on a very good recording of a real instrument. It just didn’t quite have the same feel. Unless you are using the unit as a full time portable, you really should have no problem running on battery power nearly all of the time. I just plugged in the charger when I was done listening, thus leaving a fresh charge for next time. It becomes pretty easy to remember.
CONCLUSION
Let’s recap the downsides of the QA-350 so we are all quite clear: It is a bit too large to be easily portable, yet smaller than I’d like for a permanent home component. It has a tiny display that does not give enough information. It only gets about 6-7 hours play time before needing a recharge. It is limited to 16-bit/44.1kHz .WAV files stored on 16GB or smaller SD/SDHC cards. It needs an adapter, which is not included, if you want to use the optical digital output. Perhaps worst of all, it does not have the imposing looks or the prestigious reputation of a high end transport from a famous maker.
Now that we have that out of the way, we can focus on the strengths of the QA-350; namely sound quality. This thing just sounds unbelievably good. Not just good for the price or good for the size, but good period. The amp section is easily on par with the $100 Vivid V1, which is itself an excellent value. The DAC is almost the equal of my $300 Sigtone Shek D1. And then we come to the best part, which is the transport section. This sounds like a legitimate high end transport, end of discussion. Even those who don’t believe in transport hype should be willing to concede that a lesser transport can introduce unwanted jitter and noise into a system, and that there must be some threshold of quality below which we should not venture. Even as I admit my agnostic status on this issue, I happily report that this player is easily above that threshold.
The QLS QA-350 in an interesting study in marketing. I see 2 clear target markets, and they are on opposite ends of the spectrum. The first group is just starting out and wants as much bang for the buck as they can get. The QA-350 delivers in spades, and sounds excellent even as an all in one unit. Later on down the road the budget user can upgrade amplification and digital conversion as funds allow. But even right off the bat they are rewarded with very high quality sound, at a lower price than would otherwise be possible by assembling individual components. The second group is full of seasoned audiophiles with plenty of money to burn. They have likely spent more on a single cable or vibration reduction tweak than this entire player costs. This group should not hesitate to try the QA-350 as a transport; I think they will be pleasantly surprised. As an added bonus, the process of converting and loading .WAV files might add just a touch of nostalgia as they pine for the days of washing, demagnetizing, and cuing up their favorite LPs. Or perhaps they still do that.
In any case I'm very impressed with the QA-350. It isn't exactly what I was originally looking for but it does the job quite well, and in fact I have no problem using it as the heart of a multi thousand dollar system. It has a few downsides, but those can be overcome by patience, and they don't have anything to do with sound quality. I'm definitely hanging on to this until QLS or some other company releases a full sized component that sounds this good.
