Used cables $1k - SF Amati and Bel Canto RF1000??

I tend to agree with Jkj25. I've used both the Supra and Canare cables and neither are bright; the Supra I remember being extremely neutral, in fact.

Have you experimented with speaker toe-in? You may need less.

What's your source? If persisting with cable experiments, going from single-ended to balanced is not a bad idea. Perhaps you also want to look into power cords as well, to which some Class D amps are quite sensitive. Kimber PowerKords are good.

Have you tried toeing your speakers in or out or setting them up in any configuration that might work where the tweeters are not firing directly at you? That should reduce any hotness in the top end.

For example, I have BC ref1000m amps running Dynaudio and OHM Walsh speakers.

I like listening at decent volume regularly and the Dyns, which totally live up to their name, can be a touch too hot in my main 12X12 listening room with tweeters firing directly at me.

I use an asymetrical wide speaker setup with each just a couple feet from sidewall, a few feet from rear and tweeters firing well wide of my prime listening spot. The sound is magnificent and most absorbing this way not only in terms of frequency balance but soundstage and imaging as well. Don't be afraid of trying less conventional setups, even assymetrical ones, if they might work in your room. Speaker orientation and position can make a huge difference. I'd look at that first before changing anything else.

Also I would mention that I find the BC amps to be more relaxed in the top end than most other amps I have used in the same setup.

I'm using my win7 laptop directly into a Bel Canto Dac3, via the Supra into the Ref100's and now have Harmonic Technology Pro11 speaker cables which helped.
I'm considering changing DAC and/or amp as I belive the previsou posters commnets that it's a deeper issue here. Idid try some BelCanto sourced Cardas which sounded a litle better.
I auditioned Classe, Modwright and Levinson and still found each a little too bright. The Levsinon 532H was best overall with a nice blend of transparency and weight but stillleft me feeling like a little more natural warmth was missing.
Do I need to try Pass Labs or Mac???
Thanks all.