It's going to depend upon the specific unit. While it's true that a pre-amp adds another stage, and thus potential for noise or distortion, it's also likely to have more power behind it. Depending upon what the next stage is (and maybe even how long the cable is), this might or might not matter...

To answer your original question, a DAC takes a digital input and produces an analog output. The Macbook's digital output should be fine. In fact even the analog might be, but the digital definitely is.   Your receiver doesn't have digital inputs, so you need to convert digital to analog...

I don't see anything unexpected in the screen shot of audio/midi. There will be no controls, and the volume control will be disabled, because the digital signal is being send straight.   I've found that the connector is very stiff, and that optical plugs don't go in as far as with other...

I haven't heard it, but Arcam does a good enough job generally that I assume it's good. The only disadvantage I see is that it seems to be just a DAC, not a headphone amp. I have a Benchmark DAC-1 from several years ago. I has a fairly good headphone amp built in.  

Unfortunately the sound is a bit different for the different phones listed. The three sets here seem to the be standard recommendations for moderately high end conventional phones. I have a Sennheiser HD580 (an older model in the same series as the 600 and 650), and a Beyerdynamic HD880. I...

To use a digital output with headphones, by definition you need a DAC. I don't know what you consider expensive. The Headroom Total Bithead is $150.   Newegg has a Turtle Beach USB DAC/headphone jack for $28. I don't know how good it is.  

I find the sound from my ADS L500's to be fairly matched to my Sennheiser HD 580 headphones, though I think the speakers do somewhat better.   This is with good electronics: A Benchmark DAC-1 from iTunes driving the headphones and supplying input to a NAD integrated amp for the speakers.  ...

> I still actually believe that FLAC and these other "lossless" formats aren't really lossless. They also have bitrates. And some go quite low, seen FLACs going like 500kbps. So if you have the same CD, convert it once to FLAC 1000kbps and again to FLAC 500kbps.... are the two resulting FLAC...

I do my audio on Mac OS, so I'm not the one to ask about details of processing on Windows. Apparently things have gotten a lot better on windows in the last couple of versions.    Unfortunately changes can occur at lots of different places: iTunes, when the OS gets it from iTunes, and when...

On the Mac at least I'm pretty sure the operating system will output at the speed you choose in Audio/Midi. The state of your LED's supports that, and so does the indicator on my receiver.   The best data I have is that when iTunes starts it gets the current speed from the operating system...

It sounds like you're already looking at headphones that are compatible with an iPod. As you have probably found out, many of the better phones need more power than an iPod can deliver.   For a good intro to the dangers of hearing loss...

I'm surprised no one has asked you some obvious questions:  * what kind of music do you like? * what is the source? If it's a hifi system, the receiver will be able to power phones that wouldn't do well with a portable device like an ipod * if you're going to be using it in public, do you...

What's your current setup? It's question of what your weak point is. The thing is, if you don't have an amp, it's hard to see how you're going to use a DAC. Where will the output go? I have two rooms, one where I use a receiver, and the other a Benchmark DAC-1, which is a good headphone amp as...

I don't see how to debug someone else's system. There's just too many parameters, and I'd need to have exactly the same setup. But it could be the receiver, as you think, or it could be some kind of software issue. Historically WIndows sound has been complex. If you don't get it right, you can...

The reason software is an issue is because playing audio doesn't just copy bits. Some computations have to be done, and they can be done well or poorly. This is true for both computers and CD players. CD's are at 44.1 KHz. A lot of equipment, including some of the DACs use other frequencies...