Originally Posted by ginseng
Thanks for the really great help. I'm also wondering, if I buy the HDVD800 amp from sennheiser, how would I connect it to my computer? I currently have an Apogee Duet. Would I connect my headphone to the HDVD800 to the Duet, then to my computer? Or does an HDVD800 replace an Apogee Duet?
You replace the Apogee duet. The HDVD800 has analog inputs, but it also has three digital inputs (hence, its own DAC - digital to analoque converter - circuit inside), one of them is USB. So you just hook up the computer via USB.
Originally Posted by ginseng
Oh I should also mention, would an HDVD800 be ok to use as an input for my studio monitors? (I have a pair of JBL 4328, and two subwoofers with a similar model #; 4-something-something-something)
You mean an output going into the studio monitors? I checked the product page and the HDVD800 only has analogue inputs, no preamp output. Your Duet has a pigtail that gives it a proper preamp output going to monitors, correct? If you need studio monitors it might be better to just stay with the Duet. I'm not sure what it sounds like, but I'm one to think it may have a decent enough headphone amp circuit (at least for one powered by USB), and if you can't tell the difference between its DAC and headphone amp vs the soundcard, then you could probably stick with that one for a while until you get to listen to a an amp with its own power supply without buying it, and then you can tell for yourself if you can hear the difference.
The thing is, while it isn't exactly placebo, a better amp's changes will only be readily apparent if the device it is being compared to is absolutely horrible at your listening level (which doesn't need to be loud).* If your listening level for example gets no distortion, then listening at the same level with a better amp would probably have very subtle improvements in transparency, bass response/tightness and overall PRAT since the amp/soundcard/Duet you were previously using wasn't distorting yet. Worse yet, what if it actually is distorting, but you can't tell that there already is some distortion? At this point you would either be absolutely wowed by how much clearer it is, or you would not hear anything and hate everyone who told you to blow money on that amp, without much of a middle ground.
Edited by ProtegeManiac - 2/26/14 at 2:15am
*Just an added example of how clean and how much reserve juice a real amplifier has, my brother once put his hand on my shoulder - totally did not see him walk past the flat window, nor heard him open the main door then the guest room door, and told me to put the headphone down on the desk. Guess what - I could use it as a speaker. I don't really even listen that loud, but when I turned it up for one of my favorite power metal songs, I turned waaaaaaaaaay up without realizing how loud it was just because my perception of loudness takes into account distortion. And I'm someone who would normally say, "the heck do you need that much power for?!" Checked the specs and apparently my amp also makes around 1watt per channel - something that wasn't mentioned in the reviews I read. This was on low gain though and when this happened I had it on full tilt; on high gain I can't get past 12:00 on the dial unless it's a low average level classical music CD.