What type of output tubes does your Baron have? They ship with 5881(6L6), EL34, or KT99. Of these, only the KT99 would have any propensity towards brightness. If you have one of the other tubes, I would say the problem is your room(and I don't think you listen in a vault) or you. If you have KT99, you could try a switch to KT88, this will help. But it sounds like you are VERY sensitive to this brightness, if so try EL34.
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?