This was also posted in the computeraudiophile.com forums.

I’ve patiently waited for Esoteric’s D-07 since it was announced last year. It has still to find its way to Sweden though, apparently due to a change of distributor for western Europe. My DAC fund is still a work in progress, but today I decided to stop waiting for the D-07 and instead test the D-05 against Weiss’ DAC202, to at least get a sense of the difference in “brand sound”.

I spent two hours with them, in the Audio Concept store in Stockholm. I’m familiar with the room from previous auditions, and the equipment was MBL 1531 CD player (used as transport), MBL 5011 preamp, MBL 8011 amps in monoblock mode. Speakers were Focal Diablo Utopia since that’s what I have at home.

My main musical diet sits distinctly outside of conventional audiophile material: Lots of electronic music, often in the extreme ends of the ambient/noisy spectrum. I’m not primarily seeking the illusion of real instruments. I tend to be drawn to things like dryness, control and resolution.

Starting with Weiss, I found it exquisitely smooth and with an almost overwhelming spatiality. I found myself thinking that it’s almost as though it adds a reverb to the signal, but in the most flattering way possible. I came to think of MBL speakers with their unbeatable 3D soundstage, but now coming out of the much more directional Focal speakers. At one point I wished the sound was a little more up front and direct; The hugeness of the sound cloud, just as with MBL speakers, takes some edge off of those really ultra dry, in-your-face sounds. The midrange of this DAC is really something extraordinary though, probably the best I’ve heard.

Changing to Esoteric, there is a sense of ruthless and unrelenting precision thanks to its much drier and more direct sound. This sound is much closer to what I’m used to from other equipment, and the lesser spatiality gives the treble a greater sense of laser-like focus, projecting the sound straight into your head. The soundstage not only lost some depth but on a few tracks I found stereo imaging a bit more diffuse and unprecise as well. I even went as far as making sure I hadn’t accidentally shifted the channels! This really says something of the 3D sound from Weiss. In terms of dynamics I found them roughly equal.

Overall I felt more at home with the treble from Esoteric, but I’m aware that this might be because that’s the kind of treble I’m used to. I have no problem seeing the Weiss treble have benefits in the long run.

I tried cycling through the different upsampling modes (off, 2xf, 4xf, dsd) a few times but had difficulty hearing much difference with the music I was playing. I didn’t toy around with the filter settings or PLL modes.

Finally I went back to Weiss for a few tracks. The spatiality is really impressive, again almost to the point where it seems too good to be true. Nothing was coming out of the speakers, the sound was just there. With Esoteric some sounds were clearly centered around the speakers, as is often the case with electronic music. I was hearing the same amount of detail in the treble with both DAC’s, just presented very differently. Weiss has more detail and more liquidity in the midrange – it must be pretty much unbeatable here, regardless of price. In the bass they were roughly equal – at first I thought Esoteric had a little more omph, but then on some tracks the roles were reversed. A draw.

I found this both interesting and difficult. Weiss’ 3D capabilities were so amazing they’re borderline gimmicky, perhaps because my ears aren’t used to it, but still. Esoteric’s sense of precision and focus in the treble — without even the slightest harshness, imbalance or grain — speaks strongly to my audio instincs. Yet Weiss was at least equally detailed and so absurdly smooth…

I will listen more, but I think after round one Weiss has an edge. I would gladly make myself more acquainted with that fantastic 3D sound, and the smoothness tells me fatigue will never be an issue. It’s also a bit cheaper. Still, and I can’t help repeating this, that Esoteric treble speaks to me somehow.

I have been running a Windows-based, self-assembled computer as our home server for the last few years. It’s served us very well; The thick chassis walls, rubber-suspended hard drives and passive CPU cooling made it almost entirely silent. The dedicated RAID card kept my 4×500GB Samsung drives in order and provided both adequate speed and a basic level of security for our precious music archive (ripped from our own records, mind you). It ran Squeezebox Server for music streaming, PS3 Media Server to stream video content through our PS3, an FTP server so I could access music at work and a remote desktop client for whatever else I needed to do.

On the downside, it’s about as energy efficient as whipping cream with a helicopter rotor. On top of that, all the extra services hampered performance for music making and the system began to crash at an alarming and increasing pace earlier this year. So what I really needed was to split the computer from the storage, so that one could be turned off while the other kept chugging.

Plenty of evenings were spent reading up on NAS servers: Makes, models and reviews were scrutinized while I tried to figure out what I really needed. Maybe a mac mini with some direct attached storage would be better? Or a new PC with an iPad for sofa surfing? The web, although still just in its teens, provides a wealth of research opportinities and evaluation tools almost unfathomable a mere 15 years ago. I used Swedish price comparison juggernaut Prisjakt.nu for compiling a range of potential solutions. The site allows me to compare specs side-by-side and to find cheap prices not only on single components but on entire upgrade paths, including the tracing of price trends over time. On top of that, it aggregates both professional and consumer reviews, allowing me to dig deep into the real world performance and user experiences for each product.

My list of needs for a storage & home server solution quite soon boiled down to the following:

• Raid5 or equivalent redundancy
• 4 disk bays or more – we have a lot of data
• Reasonably quiet – It’ll be in a separate room, but I want it as close to inaudible as I can get
• Good speed – My previous experience with a ReadyNAS NV+ wasn’t overwhelmingly impressive in this department, so the new Qnap *59 series and ReadyNAS NVX & Pro units caught my attention thanks to their performance in review benchmarks.
• The ability to run Squeezebox Server – This is absolutely essential. We have all our music as FLAC, and I intend to stick with the Squeezebox Duet for the foreseeable future.
• Torrents – Our level of music nerdery requires a lot of research, and we mainly rely on BitTorrent to check out new stuff before placing orders. Having this centralized to our home server rather than running on laptops that need to be left on over night just to wait for a damn torrent is a huge convenience.

In the middle of pulling my recently acquired hair over which make and model to go with in order to make sure I’m as future proof as possible, one of my Prisjakt.nu wishlist shopping carts suddenly dropped 2000 kronor (≈€200). The reason was that one of Swedens biggest and most highly regarded retailers suddenly (and perhaps mistakenly) slashed the price of the Netgear ReadyNAS NVX. I was lusting for the 6 bay Pro version but the fact that they also had an an eyebrow-raisingly generous price for the 64MB cache version of Western Digital’s 2TB Green Power disks sealed the deal. So to conclude the ridiculously inefficient blabbering so far in this post, I now own a ReadyNAS NVX, running it with 4×2TB in their proprietary Xraid2 configuration.

So, what’s it like? While I’m taking a risk running it with disks not in the official hardware compatibility list (only the 32MB cache version of the drive is listed as of this post), I must say I don’t think I could be happier with my purchase now that everything is up and running. It wasn’t all smooth sailing though: After setting it up it immediately started rebuilding the array as one of the disks seemed to cause some sort of trouble. This may be normal operating procedure (I’m lazy and  didn’t RTFM) but it took 24 hours before I had full parity. Populating the array from the Windows Vista box was both slow and peculiar; From the Raid5 array to a SATA disk in the same box gave me about 50MB/s, from the SATA disk to the NAS about 40 MB/s, but from the Raid5 array to the NAS I got an average of just 25 MB/s over FTP. When using a normal windows file transfer through CIFS it was even worse, dropping to well below 10 MB/s. But only from the Raid5 array! It took me two days before everything was transfered, and once that was achieved I noticed that over AFP I got way better speeds, even though it involved puny little 5400 rpm laptop drives. Since we’re aiming for an all Apple home, this was just fine.

Squeezeserver came pre-installed(!) but not very up to date. Changing to the very latest version, which Logitech thankfully keeps up to date with the Windows version, was very straightforward desipte involving quite a few steps. A full scan of our 1.5TB library takes about 2-3 hours with the new version, which is very impressive. I had fears that the rather demanding web GUI, which lagged notable from the 1.86GHz dual core Vista machine, would be even more sluggish on the comparatively weak, embedded single core CPU of the NVX. I was pleasantly surprised that it runs much quicker! Everything just feels snappier, and while it’s still not completely instant, I can’t say I have any complaints. It’s certainly better than iTunes…

There’s a BitTorrent client provided by Netgear, but it wasn’t preinstalled on the NVX. Instead of that official one, I decided to go with the slightly more accomplished Transmission client. It was very easy to set up, has plenty of neat features and has been running flawlessly so far. I had a torrent that was almost finished last night, and now 24 hours later I noticed it had seeded a whopping 450GB since yesterday! This shows what an insane throughput speed the ReadyNAS NVX is capable of, with over 5MB/s on average the whole time.

Setting up user accounts with their own private shares is super easy, as is Apple Time Machine support. The DLNA server works great in our scarce few tests so far, but it lacks the live transcoding abilities of the PS3 Media Server. There might be a good alternative out there, but I haven’t looked yet.

My overall recommendation for anyone looking for a quality home server with needs somewhat similar to mine is to get the ReadyNAS NVX unless you absolutely need the corporate/enterprise features of ReadyNAS Pro or Qnap *59, or feel that a 4 bay NAS is too restrictive. I hope my storage needs are now filled for the coming 3 years at the very least.

…We’ll see if it gets to stay.

Used units of the Pass do surface on occasion, sometimes at the very outskirts of my financial reach, so perhaps it’s still an option. But buying second hand will make it very difficult to do a proper evaluation and I have no desire to buy anything blindly.

While my budget is insufficient for an integrated amp that does my speakers justice, I could cut the investment in half by just buying half the amp – I could get a separate power amp.  The problem, of course, is input selection and volume control. But if I can live with a huge bottleneck for a year or so, I could use my Allen & Heath Xone:42 DJ mixer as the preamp! Perhaps the bottleneck won’t even be that enormous – it’s one of the finer sounding mixers on the market, after all.

A benefit of the mixer-as-a-preamp approach is that by the time I’ve saved up (or acquired though forays into male prostitution)  enough money for a preamp, there might be more and better options of DAC/preamp combos than the Benchmark DAC1 PRE. Neither Esoteric nor Weiss built analog throughputs into their latest designs, so we’re probably a year or more away from proper competition in this category. With such a unit I could still get a two-box option by going with power amp and dac/pre instead of integrated and dac. Not counting the phono amp of course…

The downside of this is of course that I will have glorious speakers and a great power amp but mediocre sound for a year or more. Considering all the money and the effort that goes into this, which is about the lust for music in the end, it’s not a very attractive proposition. But neither is spending huge amounts of money on something that isn’t quite right.

On a whim (and after a beer or two), I listed my Lyngdorf TDAI 2200 amp for sale on Friday night. It got picked up by a new owner less than 48 hours later, so now I’m really in a hurry, but at least I’ve freed up some funds. The Stockholm Highend Fair is just a few days away, and hopefully I’ll find the amp of my dreams there, just like I found my speakers last year.

I think the deeper insight from all this is how much a consumer needs to know to make informed decisions. To confidently judge whether to spend money on a USB cable or dismiss it as placebo and a waste of money, the following needs to be understood:

• The fundamental difference between analogue and digital audio
• Pulse Code Modulation data structure, with bits and sample points
• How a clock pulse is used in D/A conversion
• The concept of jitter and its detrimental effect in the D/A stage
• Jitter supression using a Phase Locked Loop, or PLL
• Jitter supression using a memory buffer, and the inherent problems of buffer overflow or underrun
• The principles of packet data, with handshakes, tokens, data and status
• The difference between bulk and isochronous modes in USB
• How adaptive isochronous mode is fundamentally different from asynchronous isochronous mode
• Understanding the physical principles of electromagnetic interference, EMI, as it applies to cables

That’s just the basics for whether a USB cable can theoretically make a difference. No wonder the old hifi dinosaurs get it wrong.

A problem with integrateds is that you can’t upgrade single components. In my case it’s not just pre and power amplifiers that are in a single hull, but also DAC and DSP room correction. I can’t buy a new DAC since the amp has no analogue inputs, and with no analogue outputs other than speaker terminals, I can’t use it as a preamplifier either.

I actually can play vinyl still, but it’s cumbersome; My DJ Mixer also functions as a USB sound card. This means that it has built-in AD/DA. But to get that digital signal to the amp, I have to connect the USB to my Macbook Pro and then use it’s jitter-ridden optical output to the amp. Not only do I get USB and optical cables hanging like trip wires through the livingroom, but it also occupies my computer. On top of that, I don’t think the A/D of the mixer is quite top notch, regardless of how well its analogue parts perform. So to solve the most immediate problem which is that of vinyl playback, I’d need a proper A/D converter.

I’ve bought a Roland JP-8000 synthesizer, but I haven’t used it yet since I don’t have a sound card with MIDI. I could actually solve that as well as the ADC issue with a higher quality firewire sound interface, which I could also use for ripping vinyl to FLAC (Ican with the mixer too, but there’s that ADC quality concern…). But in order to make that investment really worthwhile, it should have a really good DAC section too. The RME Fireface 400 looks to be one of the finer products in the category (compared with cheaper options like still fairly potent TC Konnekt 24D) but considering how many things it does for the price, its digital circuitry is unlikely to stand even a sliver of a chance against something from Weiss or other single-purpose hardware. But those on the other hand are so expensive that I’d be better off putting that money towards an analogue amplifier, as the very point of the ADC route is to spend less money by getting to keep the Lyngdorf amp.

There is some middle ground however; The Metric Halo ULN2 is an external firewire interface just like the RME unit. At more than twice its price it’s still half of what I last saw the Weiss ADC list for, so it’s somewhat viable. The ULN2 has been getting a lot of attention in the computer audiophile circuit, where it’s used as a DAC. So I could then get an ADC to use with the Lyngdorf for now (and for vinyl ripping) as well as a good DAC for later when I upgrade the amp, and not immediately feel the need to upgrade again. So far so good, but of course there’s a drawback: It doesn’t have MIDI, so I’d still need a separate unit for music production. At it’s price, I would have needed all three legs to stand on to justify the purchase.

Even if I were to find the equivalent of a ULN2 with MIDI, I’d have to move it from the studio room to the livingroom each time I wanted to play vinyl. It would also mean that I couldn’t be making music in one room while my girlfriend plays vinyl in the other, so ultimately this path will not lead to a satisfactory solution. Perhaps if I found some sort of decent quality ADC for €100 or so, I could justify the purchase as a temporary fix. But it feels very uncomfortable pursuing a solution that is so short sighted and flawed. Back to the drawing board…

Having poured so much time and money into my speaker purchase, it would be wasteful to lower my standards and efforts for the other components. The required patience is in short supply however, as all my hifi investments from here on will have a smaller effect on the sound than the speaker upgrade brought. It’s tempting, then, to just go with what is affordable and sounds decent and get the whole thing over with. But where patience is scarce, ambition still soars high – I know myself too well to think I can find contentment with anything that isn’t thoroughly researched, auditioned and compared.

My main problem right now is that there’s a huge ever-branching delta of upgrade routes, and each one presents different problems in terms of equipment evaluation, system coherence, audio philosophies, financing and everything in between. In an effort to make the whole endeavour a little less intimidating, I’ll try to put the available paths into words. It’s all for my own benefit, but on the off chance that someone else finds it interesting, I’ll post it here.

But before I go all Freud on issues of amplifier technology and cables, lets look at what my starting point is. After buying the Focal Diablo Utopia speakers I immediately started looking at other components, and felt that a better DAC would provide a sizeable improvement. Many people don’t realize what a huge difference in sound there can be between CD players, and this has everything to do with the DAC. I was also painfully aware that my NAD C370 amplifier wasn’t the poster child of resolution and elegance, nor were my Technics 1210 turntables with their shitty stock tone arms and DJ cartridges. Last but not least, room acoustics is a huge factor in any audio system, so perhaps I should address that before everything else?

In the midst of this I came across a rather appealing deal on the Lyngdorf TDAI 2200 RoomPerfect amplifier. I won’t get into deeper technical details here, but it’s a digital amplifier, and hence has digital inputs. It also comes with a microphone and a DSP circuit that lets the amp adjust the sound based on room acoustics, speaker placement and listening position. As this solved the issue of DAC, amplifier and room acoustics (sort of) in a single unit that I could actually pay for, I bought it.

Without the RoomPerfect stuff, there was a small but noticable improvement in sound. The highs got a bit more texture and the sense of overall control improved. Calibrating the thing for the DSP correction gave some difference in the bass, but not by much and it was more different than it was better. If the units display is to be believed, my room and equipment needed only very minor adjustments, so as it turned out this feature wasn’t all that necessary. It was certainly no DarTZeel, but the overall sound was very nice, and honestly one I wouldn’t really be in any rush to throw more money at.

There is however a small problem with having only digital inputs, namely this:

I could no longer play vinyl, as the amplifier lacks analogue inputs. As you can see, that is quite a large amount of music now quarantined indefinitely. Running analogue signal to a digital amplifier is technically unappealing since it means an unnecessary A/D–D/A conversion, but right from the start I regarded the Lyngdorf as a temporary solution anyway. Upgrading the amp with analogue inputs is about €500, which isn’t cheap but at least somewhat agreeable. What is absolutely prepostrous however is that you can’t install the card yourself, and it has to be done at the Lyngdorf factory in Denmark. Better yet, it takes 5 weeks. There’s no fucking way I’d be out of music for a whole month, and the stupidity of this policy means I will absolutely refuse to take this route.

This is where I’m at now. I have a device that needs to be replaced with an amplifier (integrated or separates), DAC, and acoustic treatment for the room, and then I also need to improve the vinyl rig. Where to begin, how and for what cost is what I need to figure out.

I normally just write stuff here for my own enjoyment, as a way to flush my system of thoughts on a certain topic. But with digital audio I’ll see if I can fire up my inner philanthropist and start at the very beginning, going through things I’ve already known for 15 years. I think it will be an interesting challenge and it would make this series a lot more complete if I do. I will attempt to put everything in laymans terms, so even fundamentalist vinyl cavemen can follow my reasoning.

The first thing I need to define is what digital actually is, especially in terms of audio. To do that, you need to know how sound works, but I won’t regress into the basic physics here. So assuming that you’re familiar with the fundamental principles of waveforms (like the sine wave in the oscilloscope above), let’s look at how they are stored as data rather than as a groove in a vinyl or magnetism on a reel tape.

Imagine a chess board. It has 64 squares arranged in an 8×8 grid, denominated A-H along its X axis and 1-8 along the Y. In chess you cannot place your pieces on E4-and-a-half or anything like that; they have to obey the grid, so you’re either E4 or E5. This same type of rule exists with digital audio, in that a sine wave cannot be drawn as a smooth curve like in our analogue oscilloscope screen above. In fact, the image above has a faint square pattern on the screen, so imagine trying to approximate the sine wave by tracing the dark lines of this grid. This is how sound is stored as data; a series of coordinates with time along the X axis and amplitude along Y. The horizontal distance, or time, between these coordinates is constant. So that value is just a frequency rather than coordinate data for each point. This frequency is kept by a clock, and we’ll back to that later.

As you may guess, the finer grid you have, the closer you get to analogue sound. Inversely, a coarser resolution will reveal more of the unnatural sounding sideeffects of digital sound. There is no information of how the waveform is supposed to look between the points of data. There is simply no information there, so after each sample point the waveform is drawn straight ahead along the X axis until the frequency clock says it’s time for a new data point. Once there, the waveform is drawn straight up or down to get to the new coordinates. Because of this, the waveform isn’t drawn as a connect-the-dots chart, but with orthogonal angles:

The vertical axis, which denotes amplitude, is stored as a 16 bit value in CD audio. Now what the hell does that mean, you might ask. A bit in digital terms is a single one or zero, so at 1 bit you would have full amplitude or silence – 1 or 0, respectively. At two bits, you can have four combinations: 00, 01, 10, 11, essentially meaning you could have four different amplitudes in your waveform. So moving all the way up to 16 bits, there are 65384 possible combinations of amplitude. While it might be difficult to hear the difference in loudness between 47361 and 47362 in amplitude, there are other reasons to desire even higher bit depth.

So that’s the basics of CD audio, really – a clock-timed series of amplitudes stored as a 16-bit values. When converting something to digital, the strength of the electric signal in the microphone is measured at the rate of this clock, and stored as amplitude values. When playing it back from digital, the amplitude values are read at the pace of a new clock (hopefully indistinguishable from the recording one!) and a new electric signal is throttled according to these amplitudes. It’s a bit more complicated than that, but I’m sure you get the point.

Now that the basics are laid down, my next post will go through the ways in which these conversions, mainly focusing on digital to analogue, can get messed up and how to avoid these pitfalls.

A slight disclaimer: The above explanation of digital audio is for pulse-code modulation, or PCM for short. There is another, perhaps slightly less intuitive way of storing sound as data that is called Pulse-Width Modulation which is used on Super Audio CD’s under the name DSD. Since it’s trickier and far less common I won’t describe it further here.

First of all, I need to figure out where to aim my priorities next.

My current amplifier, while immensely powerful, is not the poster child of resolution and finesse. When I heard the darTZeel pre/power combo drive the Diablo’s big brother Scala Utopia it became very evident that these speakers can convey a lot more than what amplification a tenth of the darTZeel price is able to summon. In fact, my amplifier cost one fiftieth of the darTZeel combo…

Another step back in the signal chain, and we get to my Squeezebox Duet. The user friendliness of this system is of such a magnitude that I honestly don’t know how I put up with shifting CD’s before. A server-based music system is an absolute necessity for me now, and I can’t even imagine going back. However, it’s a rather cheap device. Considering the price of the Receiver, which is the bit that actually plays music, it’s amazing that it sounds as good as it does. The thing includes a wireless receiver & transmitter, wired network card, DAC and unbalanced RCA output stage, all for the price of a parking ticket or around 6-8 CD’s.

While I’m not an adherent of the Source First philosophy, I think my Return On Invest would be greatest if I gave my digital source attention before I move on to amplification. Thus, from here on my hi-fi posts will be about DAC research and other aspects of server-based music systems.

I do have a shitload of vinyl, but I’m ignoring that for now. An upgrade there might come before the digital source though, and when/if the day comes I’ll make sure to give it its due attention.

I arrived just 40 minutes before I started playing, since I had to get up at 6am on Saturday to catch the flight to Brussels and hence needed to get some sleep before playing. Then I also had to jump into a cab to go straight to the airport after my gig, so I didn’t get to socialize much. Thanks however go out to Arne for booking me, Joske and Sammy for their neverending hospitality and friendliness, Philip for the record (nice to finally meet!), Matthias for buying some vinyl from me and Billy (Cosmosis) for the nice handover and for being such a nice bloke.