If you're one of those people in search of the holy grail of audio fidelity, there's no doubt that using a PC as a complete front-end solution has probably crossed your mind at one time or another. Saving your entire music library to a hard drive and having all your favorite tracks just a few clicks away is certainly appealing, but what about the sound playback quality? Can it compete with dedicated disc transports costing thousands of dollars?

If you haven't made the move to using a PC as your front-end player, perhaps you've been deterred by the fact that PC's lack the dedicated audio engineering that we find in high-end disc spinners. Or, like me, you brought a cheap CD player and modified it to the nines and are now reluctant to invest your time in starting afresh. Such was my case until a couple of months ago when my aging Pioneer PD-S801 gave up the ghost, leaving me scrambling to find a suitable replacement.

I'd invested so much time into the PDS-801; just about every aspect of the machine had been changed somehow. Modifications to the unit included a directly heated triode output stage, fitting a low jitter master clock, replacing all audio critical electrolytic capacitors with ultra low ESR types, and replacing the stock power circuitry with ultra low noise wide bandwidth voltage regulators. Most of the inspiration for these modifications came from cruising DIY audio forums, where other obsessive-compulsive audio crazed folk like me tend to hang out.

Frequenting such places again in my time of need, I noticed that the buzzword in audiophile circles regarding ultimate digital playback now revolves around using PCs to store and playback music rather than the very best standalone transports that money can buy. It seems the buzz is primarily about three things. The first is the prospect of bit perfect data retrieval when using a suitable lossless format to burn your compact discs to a hard drive. The second is using DRC (digital room correction) to help compensate for listening room resonance and reflections. The third, using software based digital crossovers, thus overcoming passive crossover insertion losses and allowing for a more cohesive integration of drive units in multi-driver speakers.

My previous experiments using a PC with mid-budget consumer grade soundcards fell short of providing the resolution, sound staging, and detail retrieval of the modified Pioneer player. I'd put the differences down to the rampant levels of noise present inside of a PC case. After all, when it comes to soul-stirring audio reproduction, ultra low noise clean DC power is a must, and that's not something that we associate with your typical computer PSU. Computer PSUs are primarily designed to supply huge amounts of current on demand, within a certified noise band of course, but nowhere near the quality we find in a dedicated linear power supply. Hence, serious audio playback requires a soundcard designed to deal with the shortcomings of the PC's internal environment.

This leads us back towards pro audio gear used by recording engineers such as the M-Audio and Lynx range of soundcards. Most of the physical differences between pro audio solutions and your basic consumer oriented product can be put down to better components, trace routing, voltage regulation, and power supply decoupling. In addition, the pro cards feature low latency drivers that bypass Microsoft's K-Mixer and can be used with specialized software allowing all sorts of signal rerouting and manipulation. This adds up to making the pro audio offerings flexible enough for people wanting to engage DRC in a fully customized multichannel setup.

Although user reports on some of the internal pro soundcards are very favorable, my interests are stoked by external affairs. An external box presents far more interesting possibilities and flexibility to me when it comes to power supply and output stage modifications. Both are things that I'm too twitchy to leave alone and unchanged until the unit either dies under the knife or gives me what I want in terms of sonics.

One such solution revolves around using the Texas Instruments 270* range of USB - I2S and S/PDIF converter chips, which are used in several commercial outboard DACs that are rumored to be capable of upstaging even the most expensive standalone players. Better still, a range of attractively priced DIY DAC kits based on the Texas Instruments receiver chips are available that utilize levels of engineering found in commercial products costing much more. The unfortunate upshot with the TI 270* family of converters is that they're designed for two-channel use only. Those demanding external multichannel audio units will have to look towards Pro FireWire audio boxes or standalone units like the Behringer DCX2496, which has more functionality than most of us will ever need. If two-channel playback is sufficient then Logitech's Squeezebox music streamer also deserves a mention. Both the DCX2496 and Squeezebox are products that have been thoroughly adulterated by DIY masterminds and there are plenty of commercial or DIY modification packages available for both units that elevate their performance.

We aim to put some of these products to the test in the coming months while also focusing on commercial loudspeakers, disc players, and amplifiers for a range of budgets from pocket friendly to the spare-no-expense league. Today, we will take a brief look at two DIY DAC kits that we've built up and have been subjectively listening to for the past few weeks. We'll also be looking at PC-based DRC in the form of a software package called Audiolense 3.0 using some open baffle single driver speakers from 3D Sonics. If any of this tomfoolery interests you, read on....

The Test System
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  • goinginstyle - Wednesday, December 03, 2008 - link

    I agree, while I might argue about some of the conclusions or have a different opinion, the author knows what the hell he is talking about. It is obvious from a lot of the comments that people stopped reading on page two and brought out the guns. It is fine to agree to disagree but some the comments here apparently came from five year olds and not adults. Sound quality is subjective, get over it. I appreciate a different opinion than my own and found the article to be thought provoking at times. Something an article should do when covering a hot topic like audio quality. Being an old hippie myself, I still love the tubes but digital has its place now. I vote that he does another article on this subject and lets see where AnandTech takes this in the future. Reply
  • strikeback03 - Tuesday, December 02, 2008 - link

    How do you live in a rural area and not own a car? Reply
  • royboy66 - Tuesday, December 02, 2008 - link

    hi I have been into audio and music for many years it is my hobby, computers are my business and hobby. I commend you guys for covering this topic -i will download the software you have used and give it a try.
    Reply
  • Wastral - Tuesday, December 02, 2008 - link

    Well at least he talked about SOMETHING to do with the PC!

    DAC talk was good if really really wordy. Nothing like breaking points down into something someone can read.

    Not one review of sound cards of sending analog output out from the computer and its actual quality... You know the main component needed in a PC... What a stooge.

    Most People can't even hear over 16khz and the very rare person can hear around 20khz. I tested out at 18.3khz with a wave generator when I was 16. Now? Probably no more than 14khz at the age of 30. Not to mention the dB sensitivity of the ear over 16khz is next to nothing. On top of that, as I pointed out with a little thing called age your hearing decreases to 10khz by age 60 or so.

    Of course If we really want this right, it has to be decoded at the amp, which won't happen, due to there being a million and 1 codecs around. Thus, we are stuck with analog.

    Its all about your speakers and amp. That part of his article I won't complain about too loudly.

    Just his BS about tube amplifiers. 10 years ago that was true. Now its only because old Hippies are retiring and tube amps were top of the line then and they have too much money and time on their hands to burn, with nostalgia hot in their blood.

    Try recording something and then play it back with a tube amp or a Digital amp and compare the sound. No one uses Tube amps in studios. Why? Because it CHANGES THE MUSIC and is not as PURE as one can get with Digital amplifiers. They say they like it... wonderful, its not as true of a sound though, the HYPOCRITS!!!

    Everything else was typical Audiophile BS ignorance. Hell, I have even installed an outlet for an "audiophile" pointed North-South for better "power" to his amp. No joke, he whipped out a compass.

    Comments like, "I only use silver 24 guage wire." DUMB shit!! Go another guage larger in copper is a hell of a lot cheeper and gets better results.... IDIOT. Not to mention its your CONNECTORS THAT COUNT.

    Reply
  • Rajinder Gill - Tuesday, December 02, 2008 - link

    Where did I sue the word 'only' in that statement about wire?

    Seems you've done the typical thing and read what you want to read.

    My entire cable setup costs less than $40, including the interconnects and mains cables. No north-south compass in my house either.

    Connections are direct soldered where they can be and if it's practical enough. No expensive connectors used.

    I'll aslo refrain from using the derogatory language you seem so comfortable with.
    Reply
  • Rajinder Gill - Tuesday, December 02, 2008 - link

    correction meant 'use'.. Reply
  • Geraldo8022 - Tuesday, December 02, 2008 - link


    Mr Gill is trying to do some of you a favor by cluing you in, but some of the denser posters come back with talk about receivers, headphones, soundcards, measurements, double blind testing, Class D, etc.
    Someone once asked Satchmo what jazz was and his reply was, "if you gotta ask you don't get to know." I guess some of you here aren't gonna get to know. Just keep your head in the sand, or elsewhere.
    I have been into HiFi for almost forty years and it is about things like sitting in the dark at one o'clock in the morning with Sarah Vaughn. If that doesn't make any sense to you, then you don't get to know.
    Mr Gill, I thank you for this article. You keep on keepin' on.
    Reply
  • Beefmeister - Tuesday, December 02, 2008 - link

    Great choice on the Opus DAC; the Twisted Pear Audio guys do great work. I've built myself a Buffalo DAC.

    That being said, I would strongly suggest you look at replacing your Ballsie with IVY modules. IVY is capable of zeroing the DC offset from the DAC, thus allowing you to jumper the output coupling caps on the Opus. It also gets rid of the dual and quad OPAMPs of the Ballsie, which apparently don't measure as good as the single and dual variants.
    Reply
  • draak13 - Monday, December 01, 2008 - link

    Starting off with reading the article, I was getting quite pissed about how much this was going into the usual audiophile BS, where their 'prowess' of electronics goes so far as, "the resistor says 1000 ohms, but really, it TASTES like 992 ohms. There's such a huge difference." I was half expecting there to be talk of putting sandbags around the room to 'enhance the musical quality of the room setting.'

    Reading further, I found that this article was quite good, and was even moderately scientific as I have come to expect from Anandtech. The choice of the recording microphone was EXCELLENT; I looked up the spec sheet for that, and the response on that mic is absolutely incredible, and is a total steal for the price you pay. Kudos to anandtech for finding and using it. The very objective comparisons of two different dacs was quite excellent, as were the multiple recordings.

    I absolutely loved your analysis of an addition of a subwoofer into the system to compensate for the range of the main speakers. I have always been curious about how well that would actually work. Lastly, I was blown away by your DRC analysis. That's an INCREDIBLE algorithm that you have there; I love it.

    There are a few things that I could say about the choice of components, and the squabbling going on about what components "perform better", but there is an end-all test that you could do to prove what is and isn't BS. First, I can flat out GUARANTEE you that your microphone is as sensitive or more sensitive than the human ear AT LISTENING VOLUME. That is, anything that you can hear, that microphone should be able to hear as well. So, if you wanted to turn your subjective listening tests into objective listening tests, then play back those songs you were testing your setup with, but record those songs at listening position with your microphone using all of your different setups. Record them multiple times, as you have been doing in your tests. Next, using MATLAB or whatever other software, overlay the recorded waveforms and determine the differences between the two. If there truly is a difference between the different hardware setups that you were using, I guarantee that this will be sensitive enough to detect that difference, and will do so quantitatively.
    Reply
  • DeepThought86 - Monday, December 01, 2008 - link

    At the end of the day, is all this expensive tomfoolery just to listen to music? Why pay extra and turn your brain to jelly to boot? Reply

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