Reference preamp with laid back and relaxed highs

Tvad, I enjoy the Boulder 2010 for specific qualities that you are looking for. It is the most relaxed and neutral preamp I have ever heard. Good luck and enjoy the search.

I'll take the contrarian tact as usual, Grant, along the lines of something that I know you and I agree on. In this instance, I would look into solid state preamplifiers.

For one, I think this is a better combination than the conventional wisdom of tube preamplifier/solid state power amplifier. The better solid state preamplifiers are far more likely to be more laid back and relaxed in the upper mids and treble, whereas tubes can be described as more lively and forward - "engaging" in the best scenarios, and bright in the less good ones.

Solid state preamplifiers are also more likely to offer balanced operation. Of course, one thing to always check is whether a component is truly balanced, as opposed to simply offering XLR input/output jacks.

For what it's worth, trying to turn things down a notch or two in the upper mids/treble is often just as easily accomplished by attacking the room. Finally, the most usual suspect in my opinion/experience is the loudspeaker crossover, especially, in today's loudspeakers.

Look at the McIntosh C2300.

It is laid back without loosing any detail, has MM and MC adjustable input resistance phono sections, great headphones output, bass and treble adjustment (or bypass) assignable by input, HT pass-thru, 3 outputs per channel (for bi-amping or connection to a sub), looks amazing with the tubes glowing through the glass top and famous blue meters.

I have yet to find a flaw in its design. I love mine.

Threshold Fet 2 Series II. Very relaxed accurate highs and yet dynamic & detailed where you need it to be.

Check out the Classe CP-500 or CP-700. These are great preamps with exceptional user features and build quality.