Do HDCDs sound terrible on non HDCD players?

Sounds like it is the cables to me. I had similar results with Kimber and Audioquest when I demo's them a while back. Try a pair of Nordost Blue Heaven (used around $100 to $125). Or borrow some if you can. If out of your budget, then the Nordost Solar Wind.

Since you do not have an HDCD decoder, those CDs are just a plain old vanilla CD to your Planet. They should play no different then any other CD. They might just be lousy sounding CDs.

So back to your original question: No, HDCDs do not sound terrible on non HDCD players in my opinion. I have many HDCDs and can attest to it from years of personal experience.

I don't have an HDCD player. I have the Steve Earle, El Corazon, Garcia and Grisman, Shady Grove, Neil Young, Silver and Gold and they all sound much better than the average red book CD, though no better than the better red book CD's.

I used to have and HDCD capapable player but replaced it with one without the chip. I would agree, generally with ncarv's statement above. Most of the HDCD's that I have I would describe as being fairly well recorded. That being said, I could not discern any real negative difference going from the HDCD player to the non HDCD player that I currently use. There was perhaps a bit more "spatial information" or "air" on the HDCD player, but it was a tough call to make, certainly not an "in your face" audible difference. So my answer would be that HDCD discs should not sound worse on an HDCD machine.