Magnepan 1.7 too bright, HELP

Jafreeman...Clearly you don't know what you're talking about. You shouldn't post

I'm partial to Cary tube pre-amps, but I think the Prima Luna's are among the best deals in all of audio. Great, warm sound, at a reasonable price.

Also, older ARC and Mac gear that is less expensive sounds stellar as well. I like maggie with a tubed pre, and powerful amp. Mellows out the sound with the tubes and gives you great bass with the powerful amps.

Well you sort of opened a Pandora's box when you asked this question. My advice, don't spend any money right now, especially on cables or power cords. First play w/ the speaker position and the see what you can do about the room interactions. Post the dimensions of the room, where the speakers stand in the room, and what you have behind the speakers. Start with the room and speaker placement before you buy anything else. You've got a speaker, for better or worse, that is sensitive to what's driving it; however, even w/ very high end equipment Mangepans can still perform well below par if they are not placed correctly. With some more detailed information about your room the folks here will help you optimize your acoustics, first priority.

Djcxxxis giving good advice.
Usually the advice is to throw money at the problem...
Enough money and the problem will disappear.
Better to solve the problem with no money, or very little money. Then you've got something going.
I used the things in my apartment and rearranged some stuff behind my Magnepan 3.6s.
I added some bookshelves to the rear sides of the speakers to act as an absorber. They are right into the rear corners, floor to almost ceiling filled with DVDs etc. Then in the other part of the corner are heavy drapes.
I have my 3.6s with the tweaters 'inside'. I calculated a good position for my speakers, and then left the tweeter in that spot, but swapped them so the bass was on the outside of that position. Worked well. Wider, with no hole in the middle. And a better appearance too. A little better lower frequency response added in.
So try adjusting the room some. You may not even have to buy anything to get some good from it.
And then in the other site for your question, i mentioned some ferrite on the disc player cords, interconnect, and power cord. Radio Shack has some, and others, so a $15 set of three ferrite might help a bit.
I have ferrite claps I bought 20 years ago, and always find new things to do with them. So they can be a permanent part of the arsenal of things to use to adjust stuff.
One other thing i just thought of is the coil in place of the resistor for the tweeter.
Over on AA the planar asylum, a tweak of using a small coil in place of the resistor, smooths the HF. The coil is like a $2 part. i do not remember the value. but check out the AA planar forum for it.

I agree with Djcxxx. For example, if the bass is not right, that may cause them to sound too bright. Make what you have work to the best of its ability before you spend any money.