The noise only occurs if I use my DAC as a preamp. If I use a separate preamp, there is no noise issue whatsoever from my main listening position (have not bothered testing with my ear up against the speaker--what's the point when I listen from 2 meters away?).
Really odd the number of people (not just in this forum) who question the use of a separate, analog preamp. Properly designed analog preamps are transparent and provide all the benefits of full signal attenuation (so not just the sound, but also the noise floor) not to mention the prevention of an accidental full-power signal being sent when something electronic decides to reset itself upstream.
-Ed
I'm not questioning the use of a preamp. Indeed, I have several. Very good ones too. In the systems where I run more than one source, they are imperative. However, in the very few cases where your source has a very good analog output source with variable analog gain, then you might not need the switching preamp.
I use analog preamps because they provide a good analog drive section that is beyond what is available in the vast majority of DACs. And of course, it allows me to use the DAC as its maximum level, with no bit loss, while the preamp uses a good old high quality analog potentiometer. Plus the ability to switch sources and ancillary functionality that comes very handy.
Indeed, two of my pre amps take both SE and balanced inputs and convert all of that into SE and balanced... Meaning it will take an SE signal and generate a balanced signal... the magic of FETs and expensive transformers! They are indeed the most transparent things you'll never hear. Just switching and lots of current at a magic 2V output.
Plus, naturally, the ability to change the L/R balance -using one pot per side... just throwing money at it but it works.
Alps, Vishay, Nichikon, Edcor.... ring a bell? No remote! (*)
I have tried other setups bypassing the analog preamp as gain buffer, like the D90, the Ultra... but that's just for kicks to give them a try. They work, but not as well, they do need proper volume adjustment to drive the amps. Lower noise, some gain, isolation, etc... DACs with digital gain all have the need to be buffered from the amps.
However, there's a couple of DACs in my collection that are interesting: the Nitsch DACs provides a very good analog output with a very high quality analog pot, and in that system, right now, I'm only running the DAC as source, so a stand alone preamp just gets in the way.
Then, the Burson DAC has the Burson opamps and also a very good analog pot, but since that system has three sources, I kept an analog preamp in the system.
Oh, I lied, I got more than two... the Nuforce DACs all have analog sections with analog pots.
In general, I believe that DACs that incorporate a good headphone amp with an analog gain stage do not need an analog preamp in the chain.
There is also the issue of the tubes... two of my preamps have tubes with the teflon caps, Vishay resistor ladders, etc... they add a sound that I like... but sometimes, I don't want it...
So there. In my experience, if your DAC has a strong analog output section with an analog gain stage (pot or resistor ladder) AND your system has a single input, then you can go from DAC to amp directly. It does sound very good... and it saves you bucks and shelf space.
Oh, one more thing... the Nitsch has an analog input as well as USB... so it actually serves as a very basic preamp. Hmm... come to think about it, I might plug the FM tuner into it.
(*) I do have the parts to add a very high quality remote... one of these days I might go that route.