What are your cables? None of the three components you mentioned are particularily known to be bright. However, all Maggies tend to show any harshness in the system. Also, the Maggies have no bass! when you have no bass, the highs catch more attention, so that can add to the sense of brightness. Lastly, Maggies are EXTREMELY picky as far as distance from back wall, which effects the midbass and bass response. You might try moving them forwards and backwards, to see if you can increase the midrange and midbass, which will certainly help put the highs into better proportion.
Source of Brightness
I have rigning ears from the brightness in my system. Linn Genki, Meas Baron, Magnepan MMM (1.6s ordered). What is the source and solution? Robert Harley in TAS on SACD said that the CD brigthness/harshness wasn't there on the SACD and in the past the best CD players balance brightness with detail. Are high end makers walking a tight rope due to an inferior souce format?