Taming the high frequency

I fought harsh for a long time. First recommendation I’d have made was room treatment...but you have that pretty well covered - unless there is further benefit to be gained by replacing the decorative blankets behind the speakers with a couple of GIK panels. I found a Hegel H200 SS integrated to be significantly warmer than the 6CA7 tube mono blocks I had. Cardas ICs and speaker cable helped a lot too. A good deal of the pain and "gambling" with wire can be eliminated by borrowing from the Cable Co. I didn’t understand what you are using as a source...any chance this is contributing (or did it sound fine when the Krell was in service)? Finally, I assume everything is well broken in? Final thought is to consider some sort of equalizer.  Some here are very happy with the Schiit Loki.  

Good luck!

Tissue paper over the tweeters a la Yamaha NS10s in the studios back in the day!

Ghost, thanks for your input. Thinking about it even with the Krell there was some harshness at certain high frequencies regardless of the source. It is possible that the Lexicon is more adept at identifying the problem. I’ve never used any room correction software and may have to try that. Someone else also mentioned cardas to me. It may be a solution.. ... yes all been in use a loooong time. This is very frustrating.

Can’t the Lexicon be adjusted to tailor the sound? Looks like it has all sorts of settings. Reading around, I see a comment about it being harsh. The Adcom is pretty bright and B&Ws can be a bit up there too. And it’s a digital source. If no good results from adjustments, try your rig without the Lexicon.

@gillatgh - what speaker cables are you using?.

Your amp looks like a high current design?

If so - it may be experiencing an oscilation reaction with the speaker cables - i.e. if the cables have a high capacitance value it will staret oscillating - which will impact the sound

Selecting a speaker cables that has a capacitance of 10-20 pf/ft should eliminate the high frequency oscillation - if this is the problem

Van den Hul D352 or NAIM NAC A5 are two affordable cables that are low capacitance in the 10-15 pf/ft and they are pretty good performers.

By comparison - Cardas Golden Cross has a capacitance rating of 154 pF/foot.

A friend drove both his Ayre and Gryphon amps to destruction using high capacitance cables - not good.

Solid State amps having a High Current design will have this issue - whereas tube designs WILL NOT have an issue with high capacitance cables.

For high quality/resolution cables that will work very well with high current designs take a look at the KLE Innovations product line. I have reviewd many of theri products and they are first class and they work extremely well with my NAIM 5i - also a high current design.

Hope hat helps - Steve