Is my new amp TOO GOOD?

What speaker cables are you using? 
 

If you are using cables that are lower tier from a higher end brand I have found a lot of them to be tipped up. Analysis Plus and especially Nordost were pretty bad. 
 

My new Snake River Audio Signatures seem incapable of sounding shrill. They are real good in my system. Not the case with the Straightwire cables I took out. Like night and day difference. Mid bass texture and tone went up several notches and any glassiness on the top end is now non existent. 

@gjfalls 

Nice system, mine is almost exactly the same, except I am running an older C2300 preamp into a pair of mc275s monoblocked.  I am using very detailed speakers and I feel the combo works extremely well.  

@mojo771 

You have already received great advice...  Toe out, and Break-in.  As you already found, I can validate that in my system, Toe out, and height of the speaker, made differences in high frequency perception and sound stage.  
Another tip I found in the McIntosh forums was vintage Telefunken smooth plates in the preamp line stage and phono stage.  I tried them, liked them, and kept them installed.  They can help smooth and sweeten the top end, but, it will not be as noticable as "Toe out" differences.  

Thanks to everyone who offered advice.  Here's the update...

I moved the speakers a tiny bit closer and then pointed them farther away from my ears.  At first they pointed to about 1 foot behind my head and they sounded better.  Now I have them pointed even farther, so now they meet at about 2 or 3 feet behind my head.

Also, since its been about 6 weeks, I think that either the tubes have broken in, or maybe my ears have.  

I sometimes still need to drop the treble, but by only a decibel or so.  Mostly on cd quality streaming from Qobuz.  Vinyl sounds amazing.

Everything sounds so good now that a couple of times an album sounded so different from what I'm used to, that I had to check to see if it was a remaster (it wasn't).  Thats how good they sound now.

@ghdprentice 

Thanks for reminding people about break-in periods. I know most people discount that/don’t believe it. Nonetheless, it IS a reality with any kind of new equipment, although a mass-market integrated/speaker/electronics would very likely require less time. 

And assessing the upstream components after getting a new component with fewer compromises is also something people don’t seem to consider.

The same thing occurs in photography, when getting a larger format camera ( 2 1/4 format or large format) showed those who had only previously used 35 mm SLR that their 8 x 10 enlargements from 35 mm format were distorting information and actually subtracting details, but this was only apparent when someone placed a 35 mm 8 x 10 enlargement alongside a medium format (2 1/4) or large format camera 8 x 10 enlargement and could see the differences side by side. If you didn’t have  experience with a larger format camera (and larger enlargements from the negative), an  8 x 10 photograph enlarged from a slide would look perfectly fine to most peoples’ naked eye. The side-by-side comparison, even then, wasn’t immediately obvious to the untrained eye, but when the differences were pointed out by someone knowledgeable, it became clear what was missing (usually very fine details in hair, eyelashes, eyebrow, pores of the skin, or, if it was landscape photography, the textures of leaves, or plants) to the more novice photographer.

Audio is like that, too.

P.S. I have to say, I'm heartened by all the posts reminding about break-in and making sure that the previous components in the system are not responsible for what someone hears with their newer (and presumably better) components. I don't see that much in forums nowadays.

@gbmcleod 

Great analogy with photography. I am a photographer as well. I own a medium formate camera and for the last 25 years using digital... with the largest sensors always in mind because of their superiority in dynamic range and other aspects. I instantly react negatively to over exposed high-lights or poor resolution when not one else notices... or over sharpening... I really can't stand that. 

Yep, lots of similarities.