Help me - am I stupid

It means that downloaded hi-res tracks up to 24-bit/192kHz from HDtracks can be played through this DAC.  This includes capability for all lower sample-rates including CD quality at 16-bit/44.1kHz.  They often have sales, up to 20% off, so look for those.  I would recommend FLAC or wav format for your downloads.

Playing back from a Computer using USB is easy, but in order get the best sound quality, I highly recommend Amarra playvback software on Mac or Audirvana on PC.  JRiver also works on PC.

Steve N.

Empirical Audio

I think the OP is asking, What is a DSD download, and how  come my CDP/DAC can’t handle it?
  First and foremost, don’t worry as there are not many DSD downloads available.  Steve is reassuring you that there is still plenty of high resolution music available to download and suggesting one well regarded site to obtain it.
  A digital waveform can be decoded in one of two ways: PCM, or Pulse Code Modulation, or Direct Stream Digital— DSD.  There are many people here better qualified than me to explain the differences, so either wait for them to show up here or do a search.  As I understand it, DSD samples 1 bit of data, something like 2.6 million times.  The much more commonly used PCM samples a “pulse” of bits, varying between 14 and 32 bits in length (most commonly 16, the ‘Redbook’ CD standard).
  DSD is used in SACD and some downloads.  Some audiophiles including yours truly greatly prefer it to PCM, but do to liscensing issues with Sony, the inventors of DSD, it isn’t widely used.  Meanwhile, high Resolution PCM, such as the ones referenced by Steve, sound pretty damn good

Well guys - I am a vinyl man - but am getting sick and tired of the continuous price hikes for every decreasing quality of LP's - so I bought a decent CD player that had the DAC input option - it's a cayin CDs 55T.
One of my other questions that both the guys who have answered may probably help with is this?

1. I get High res if the original recording was in high res, or if taken of master tape in high res - but what is the point in upsampling?
2. How do we know what resolution something was recorded in in the first place?
3. any point in going above 96 KHZ

1) Upsampling helps by lessening the need for steep filters (for CD quality, filtering out everything over 22050Hz), it can also help reduce jitter depending on the implementation. Many DACs do this natively, so I wouldn’t do it on your own.

2) You can’t know what the original master track was done at, but it really shouldn’t matter. However, there are instances of sites selling copies higher than the master is in.

3) No, ~100kHz is the limit for peak performance for a DAC, Benchmark actually downconverts 192kHz files in order to get better performance (you can’t hear above 20kHz anyway so you won’t notice the difference).

That being said, and I’ve argued with a few people hear, DSD has no benefits that I know of and there is no need to go higher than 44100Hz as most DACs upsample themselves and better ones deal with intersample overs. And unless you have a dead (heavily treated) space, there is no benefit to listening to 24Bit, especially if we are talking 16Bit that has been dithered and noise-shaped.  

For fun, try and see if you can tell 16Bit apart from 8Bit with music playing. Now, that’s to show that music can do well in masking a high noise floor, but that’s not to say you can’t tell the difference between 16Bit and 8Bit when music isn’t playing, check this out, you can clearly hear that 8Bit is much worse, the site also lets you hear what dithering and noise-shaping does (keep in mind it’s demoing it for 8Bit).

Funny thing I find with Digital vs analogue is that with Digital you keep listening albums end to end whereas with digital you seem to skip - and its not just a matter of ease of skipping.
I went to a fascinating talk by the Editor of Stereo magazine at lat years high end show and he said its like the darkening of seismographs that always thicken and darken on a shift - the same occurs with the styli' going through digitally mastered grooves.
the few times I have heard high res I have found it much better than 44.1.
My point is that I find differences show over longer listens (lol - making my excuses early)