Here is an excerpt from the book "Mastering Audio: The Art and the Science" by Bob Katz, one of the world's best.
Converters
All the converters mentioned here are A grade or higher. The difference between an A and an A+ is extremely small, perceptable by only the most discriminating listeners, and opinions vary on which is better.
Benchmark DAC1
The Benchmark DAC1 is a 2-channel 192 kHz/24-bit digital-to-analog converter, utilizing their UltraLock (TM) jitter reduction system.
Cranesong HEDD-192
The processor section of the Cranesong HEDD-192 is described in detail in Chapter 17. Its ADC and DAC have excellent sound, at least A grade.
Lavry DA-924
The Lavry Gold converters are premium models built with discrete parts, with an extremely quiet noise floor and pristine sound quality. The DAC uses their Crystallock jitter elimination circuitry, whose PLL does not change the data. This is one candidate for best-sounding converter regardless of price.
Weiss DAC1
Weiss's excellent DAC1 with data-accurate PLL is another candidate for "best-sounding".
Other Converters
Other highly respected converters that I have used are dCS, Mytek, and Prism.
(I left out most of the stuff on analog to digital converters since you don't need that.)
After a quick Google search, here are the prices on the units he recommended:
Benchmark DAC1 = $995
Cranesong HEDD-192 = $3,620
Lavry DA-924 = $8,500
Weiss DAC1 = $6,725
Ouch, right? Although I find it interesting that some of the best converters for audiophiles are also the best for mastering, like the Benchmark and the Lavry.
However, I have heard excellent things about the Benchmark. For example, it was mostly holding its own in a comparison with a dac costing $17,000. Also, it is a good sounding headphone amplifier, although you could output to the Heed CanAmp if you wanted to.
At the cheaper end of the spectrum ...
Centrance has a plug-n-play USB DAC and headphone amp in one. It costs $400. It looks small enough to be a joke, but it actually sounds quite excellent, I've heard. I could find access to one and I own the AKG k702, so if you're interested, I can give it a test listen on some material and tell you what I think.
And the last option, something I'm super stoked about, is actually multi-purpose. It is a calibrated monitor control, the BMC-2 by TC Electronics. As soon as I have the cash, I'll be picking one up.
It has three digital inputs, which are switchable and each as memory for its own sample rate (also switchable). It outputs digital or analog, depending on which button you have pushed. The level control is
calibrated, meaning when you have it set right, you can dial to 0dB, which is preferably 83dB SPL in your ears. Then, when you want to turn it down 3dB to have a reference level of 80dB SPL, you turn the control down one dot, and the little light blinks so you know you reached it. It has a "reference" position, so when you hit that button, it returns to one volume level you preset as your reference. It also has a dim level, like a pre-defined partial-mute, and a full mute. Also, it has options for stereo, mono, and side-only, which is very, very useful if you do any audio mixing. They spent over a year developing their anti-jitter technology, and it works. It isn't empty advertising jargon!
I saved the best two features for last:
the volume control is 48-bit dithered to 24-bit! and it is only $300!
I have heard on the highest authority that the dac inside sounds very, very good, although I have only used it on digital mode at work since they have digital loudspeakers. I've heard the headphone out on decent Sennheiser cans, but you'd probably have better luck using this as a dac and monitor control but leaving the headphone powering to an amp (like the CanAmp). Even if you don't use all the features, it is an excellent price.
I've been following a discussion of digital vs. analog volume controls on a pro audio mailing list, url: http://bach.pgm.com/mailman/listinfo/proaudio In the discussion Bob Katz, the above author, discusses with others whether it is best to control volume in the digital domain or the analog domain. Bob says that he has heard great and terrible examples of both, but that the best analog monitor control he's ever heard is the Cranesong Avocet, priced at $2,800 for two channels. And the best digital monitor control he's ever heard is the TC Electronics BMC-2, priced at $300 for two channels. He thinks they are equally good, and the best of their respective realms. Since we're coming from a digital source, it just makes sense to go with the cheaper option!
Rinthe, I hope this helps. If it didn't, maybe the others will find it interesting. Sorry if it was off-topic for the thread, but I suppose your question was a little off-topic as well. :-D
Just a last thought, Rinthe, Robert Greene was discussing sound quality components in the same pro audio list. His view, which many agree with, is that the speaker (or headphone, in this case) is the ultimate determining factor in the sound. We can talk all day about dacs and amps and sources and volume controls and interconnects, but they are all small differences for the major differences speakers hold. An audiophile or true industry professional can determine which dac or volume control is best on an excellent system, but even a novice can tell you that two speakers sound different, and can probably choose which one (s)he likes more. Getting good headphones will be the biggest jump in sound quality for you right now. Powering them sufficiently is going to be next on your list (the CanAmp), but there's no reason to go hog-wild buying gear after that unless the money is spent more for the joy of the hobby than musical differences for the light-to-moderate audiophile. I hope this also helps. Best wishes.
