Product: Cleo USB DAC
Manufacturer: DiyHifiSupply - Hong Kong
Cost: $1100
Reviewer: Maarten van Casteren - TNT UK
Reviewed: November 2010

Introduction

I have been using the DiyHifiSupply Django transformer preamp for years now and it is a component that I really, really like. It was love at first sight at the time, and I've still not found anything that I like better, and that I could afford. DiyHifiSupply are based in Hong Kong and have gained a reputation for affordable and high quality preamps, valve amplifiers and other hifi components. I actually contacted them to inquire about the latest Django preamps, but they responded by pointing out that the really exciting new thing was their new Cleo USB DAC, so I ended up reviewing that. It was going to be my first experience with computer audio, but that would have to happen at some time anyway, so I bit the bullet and gave it a try. It would turn out to be a very interesting first encounter.

Many DiyHifiSupply units are named after artists. There's the Ella, the Satch and, of course, the Django. This DAC is named Cleo, presumably after Cleo Laine. The DAC only has a single USB input and nothing else, so it is for use with a computer only. This obviously limits its application, but keeps it simple at the same time, which can only be a good thing. A special feature is the fact that the USB communication part is asynchronous, meaning that the bits are not sent at a fixed rate by the computer, with the DAC having to adapt to that, but that the rate at which information is send is controlled by the DAC itself. In this way it becomes much easier to prevent jitter, as the DAC can now run an independent clock without having to adjust to another clock in the source. The technology for this asynchronous communication is coming from a Musiland DAC, but this is modified by DiyHifiSupply and now plays into an E88CC valve output stage. The Musiland clock has been replaced by a DiyHifiSupply EZ ultimate clock system and the Musiland PCB has been completely assimilated in the Cleo, which on the inside indeed looks like a collective of PCBs and wires.

The casework is compact and looks nice when you can see it, which is only when the DAC is switched off as the white LED on the front is ridiculously bright. I really had to put a piece of paper over it, because otherwise it was a bit unpleasant. One other minor point of criticism would be that it is actually quite difficult to change the valve. Trying out different valves in an output stage can be quite rewarding, as I found out with my Astin Trew AT3500plus CD player, which uses the same ECC88 valve in its output stage. With the Cleo you not only have to open the case, but it is also quite fiddly to do so, and once you've reached the valve it turns out that it is squeezed in tightly between the output capacitors, which didn't leave enough space to try my favourite EAT ECC88 valves, for example. It did come with a Tesla ECC88 fitted, and that seems to be an excellent choice, so as the EATs didn't fit, I simply listened to it like that.

The Cleo can play music with a maximum resolution of 24 bits and a sample rate of up to 192 kHz, so high resolution audio is definitely possible. There's not much more to comment on with a component as simple as this. A USB input and output and two RCA outputs at the back and a switch and the already mentioned 'death-ray' LED on the front, and that's it, save for the connector for the power cord. Of course, this is not the whole story, as the Cleo gets its signal from a computer and comes with its own drivers, which have to be installed on your computer. This was where I was in new territory, and that would soon become clear.

Setup

Initially I just installed the Musiland drivers on my Sony VAIO Windows Vista laptop and plugged the Cleo into the USB port. It worked and didn't sound too bad, so I was happy and started ripping CDs and listening to Spotify and CDs through it. This was all very enjoyable and opened up new possibilities for me, as I've never used computer audio before: I'm old fashioned and still use a CD player and a record player. The only annoying thing was the USB cable, which limited my freedom when using the laptop, but this wasn't too much of a problem. When I compared the Cleo directly to my Astin Trew CD player, I did find that the Astin Trew seemed to sound better, but I didn't think much of it. The AT3500plus is an excellent CD player, and it would take more than a simple USB DAC to beat it. At least, that's what I thought.

Then Thorsten Loesch contacted me to inquire how I was getting on with the Cleo. Thorsten used to review for TNT himself, and is actually the person who came up with the idea for the TVC (the Transformer Volume Control), so he can be seen as the father of the Django, in a sense. He is also involved in the development of the Cleo, and in that role was providing support. I told him about my experiences, and was immediately told that I had done it wrong! Presumably Windows messes with all audio that passes through it, and the only way to get decent sound quality out of a Windows PC is to bypass the Windows sound system. One way of doing this is by using ASIO, which is a way for software to access a soundcard directly, without going through the operating system. The Cleo has such an ASIO driver, inherited from the Musiland embedded within it, and it should be used like that, Thorsten insisted.

This meant I couldn't use Spotify anymore, but Thorsten recommended JRiver Media Center, and that's what I tried. This was a great success. Not only did it turn out that JR Media Center is an excellent piece of software, but more importantly, the Cleo now sounded much better indeed. Gone was the slightly grainy and flat presentation, replaced with a rich, full-bodied, spacious and well articulated sound. This was much, much better! Needless to say that this was the way I used the Cleo for the rest of the review period. All earlier listening notes went into the bin.

To be completely fair, I could have known this, as DiyHifiSupply provide excellent and extensive documentation with the DAC, giving detailed examples of how to set it up and use it in different contexts. The fact that I initially messed up should be seen as an excellent example of reviewer ignorance. It is easy to think you know what you're doing, but in the relatively new field of computer audio things are not always as you expect them to be. DiyHifiSupply should be applauded for their efforts to help audiophiles on their way. One remaining niggle is, of course, that not all software will work with an ASIO interface, but this is by no means unique to the Cleo. Your choice for the right hardware will be decided by factors like wireless access (complicated with all USB DACs), the possibility of sending music to several systems in the house (only possible with a network system, not with USB or SPDIF), the option of using it with an existing transport (only possible with a direct digital connection, like spdif or toslink) etc etc. It is quite clear that computer audio is a rapidly evolving field, and there are no real standards yet, or rather too many if you like. It is therefore very important to research the market and have a good think about the sort of solution you really want. The Cleo is mainly intended to be used with a dedicated computer to form a sort of digital jukebox, allowing you to play your music in a very convenient way, but mostly limited to a single location.

Once everything is correctly setup, it's actually not very complicated anymore. JRiver Media Center is an excellent bit of software, not only for playing music but also for ripping your CD's. Track info and covers are added automatically and each newly ripped CD is inserted in the database and can then be accessed through album name, artist name or genre. The Musiland driver controls are available through the Windows Taskbar without any problem, but the settings should be checked from time to time, as in my system it once happened that some parameters were mysteriously changed, spoiling the sound quality.

I also wanted to try HD audio. I do own a DVD-Audio disk, but that didn't really sound any better than a normal CD. I did try to find some music online in HD that I already owned on CD, but soon found out that this isn't very easy. In reality there's not much HD music for sale yet, so I decided to just use the Cleo with 16 bit 44.1 kHz files. This is what most of us will be using, and as far as I'm concerned the most important format by far.

The sound

The first thing that should be stressed is that the Cleo is intended as a proper audiophile source. Computer Audio definitely doesn't mean MP3 in this context. Actually, the 24 bit/192 kHz capabilities of the Cleo offer possibilities in the other direction: real high definition audio with the potential to sound better than CD, or perhaps even better than vinyl. This is no 'headphones only' or 'second system' component. The Cleo belongs in your main system, replacing your CD player with something that is more practical in use and that offers the same sound quality.

When all settings are correct the Cleo can really sound good, very good actually. Once I had it set up properly it became immediately clear that it represents serious competition for the resident Astin Trew At3500plus CD player. Many CDs were (losslessly) ripped to enable direct comparisons, and this proved that both players are very well matched in sound quality, with some minor differences in overall balance. The Cleo is a bit more energetic, with more air at the top end, a bit more impact in the bass and slightly more attack overall. In contrast the Astin Trew is a little bit more smooth and silky, and ever so slightly more warm than the DAC.

To get to the bottom of this I borrowed a Benchmark DAC from a friend. This also has a USB input, albeit non-asynchronously, if that's a word. We could now switch between two USB DACs and a CD player. It became clear very soon that the Benchmark had the coolest overall character, sounding a bit uninspired compared to the two other sources. The fact that the Cleo and the AT both use a valve in the output stage could be responsible for this, but the fact of the matter is that both sounded clearly warmer than the Benchmark. I don't think there's anything wrong with the presentation of the Benchmark, by the way. It probably is just being very neutral and correct. But that doesn't change the fact that this extra bit of richness in the midrange is really very pleasant and worked extremely well in my system. I used the Django transformer preamp, the Usher Reference 1.5 power amp, and a pair of SEAS Exotic single driver speakers. The Benchmark might work better with valve amplification, where the added warmth of both other sources could be a bit too much of a good thing.

Except for the warmth, the differences between these three digital sources were rather small. The Benchmark was very precise with good resolution, but a bit dry and matter-of-fact. The Astin Trew is very refined, smooth and warm, without becoming too soft or losing out on resolution. The Cleo found itself more or less in the middle: much warmer than the Benchmark, but slightly cooler than the AT. It was the most lively source, though, and without suffering any harshness or fatigue, something that often comes with a lively presentation. In comparison the AT was ever so slightly soft, but certainly not to the point of becoming a problem. Its strong points are refinement and musicality, and in these areas the Cleo couldn't match the Astin Trew. But the Cleo is the more expressive player, with more air and more drive to the sound. In that area the Astin Trew couldn't match the Cleo. Which is the better choice depends on your taste and system, with the added note that both are very warm and musical players that can be listened to for hours without fatigue. It also should be mentioned that the Astin Trew had a very nice, cryogenically treated Philips JAN valve fitted, which is probably better than the Tesla valve in the Cleo. Improvements should certainly be possible, although given the sound quality already achieved by the Cleo I wouldn't expect miracles.

Conclusion

As the Astin Trew still is the best digital source I know under £2000, matching it for overall sound quality is quite a feat for a little DAC that costs considerably less than the AT3500plus. This really is an excellent sounding USB DAC, with a warm and musical sound and a lively and airy presentation. It is refined and engaging at the same time and basically performed as well as my, more expensive, Astin Trew CD player reference. If you can live with a DAC that only has a USB input, then the Cleo represents both very good value and excellent sound. The only provision is that you really need to use it through the ASIO interface, as without that it sounds rather disappointing. Highly recommended.

Manufacturer's comments

Thanks for the review and appreciate the good result. Glad that the Cleo was able to perform at a satisfactory level, comparable to your CD player. I just wanted to mention a little bit about the role of the Cleo, and the whole computer audio scene as there is a steep learning curve.

1. Of course the most obvious advantage is being able to rip (and archive) our library of CD's to a hard drive and play them back from a computer, bit perfect with no losses compared to a conventional CDP. As we've found out, CD's do get dropped, scratched etc so this is a way to preserve music which may never be released again. 1000 cd's worth of music can be stored on one 1tb hard drive. So all-in-all a very cost effective way to protect what is likely the major component and investment of a music system -- our music library.

2. Also of interest to readers is the 2nd feature -- 24bit/192khz playback. This unshackles us from the 16/44 standard and opens up a whole new horizon for digital music. For those of us that came from vinyl and tape as our reference it is most welcome since we never got from digital what we got from analogue -- the brilliance of brass, the shimmer of strings and natural vocals. Actually I've noticed that young people can hear it right away; many come here and listen to vinyl for the first time (in their lives) and comment that they hear things they never heard with CD. Some have said that it is the first time they've heard horns that didn't blare and strings that didn't shriek.

24/192 shows the potential to recover those qualities. It is taking time to learn how to best harness all that extra data on the recording and engineering side but the benefits can already be heard on a high resolution system. While the Cleo can equal a good 16/44 CDP, 24/192 takes it to another level as we are then streaming 5 to 10x the musical information. Even Reference Recordings CDs can be ripped with dbpoweramp and produce 20bit/44khz lossless files playable by computer.

There are quite a few sites now coming on stream with whole catalogs of hirez music. Some is being produced in native 24/192. Of course such music must be purchased online.

[Go on to read what Nick Whetstone thinks about this DAC]