Harshness in Midrange??? Any Help

my votes for the speaker wire. or perhaps the scd1, but methinks the speaker wire.

One or more dedicated AC lines should help. I have used the Kimber silver (8tc?) speaker cables and found the sound harsh. I greatly prefer Ensemble cables, also at some point in every great "digital" system, the DAC becomes the weakest link.

What is your room acoustics like?

What listening level are you using?

Is it only certain recordings?

I very much doubt there is anything wrong with your system. Alan Parsons uses your speakers (Pink Floyd fame). The rest of you gear is pretty much accurate at audio reproduction. If it sounds harsh then it probably is - it may just be the source!

What were you using before as system/speakers - what is your reference to say some recordings are harsh (The majority of speakers are voiced to be recessed in the upper mid range to avoid this issue...it is called the "BBC dip" - it may be why you think it sounds harsh compared to other consumer hi-fi you have heard)?

You can remove harshness with a PEQ by applying a slight dip at 4Khz.

How old are the tubes in the ARC?

Room treatment thats the ticket. Your gear is fine and I would think before you put the blame there try working with the room. I would say once you have treated the room properly or at least got it under control,then and only then would gear change be in order.