Brightness

EMF in my setup has caused unbearable brightness. I suggest, if you have not already, eliminating EMF as the problem source before blaming your system. What, if anything, did you move or reroute when your system became bright? Did you place any of your electronics closer than 3-5 inches? Do you have a power cord near or touching your speaker wires or any cables? Are your cables off the floor, especially power cables (rebar spacers @ 50 cents each are phenomenal for this)?

Cross your cables, if you must, at right angles, and don't let any cables touch. Keep power cords as far as possible from cables, at least 3 inches. I find that if I move cables in my system, for whatever reason, it takes at least 24 hours, if not a week, for my system to return to glory.

Recently I battled unbearable brightness upon substituting 4 expensive power cords for my stock PC's. Were the power cords incompatible with my electronics? I placed calls to manufactures and distributors, moved electronics around, rerouted cables, brought diffusers into the room, adjusted my speaker position and toe in. Somethings decreased the brightness, but nothing eliminated it. Ready to pull my hair out after months of searching for the source, I traced the problem to the 4 stock, unplugged power cords which, upon taking them out of my system, I placed in front of one of my electrostatic speakers. After taking the cords out of the room, the brightness vanished. 

The Unbearable Brightness of Listening

(Sorry....too obvious, couldn't resist.  Happy for you the demon was vanquished...*s*...)

All this negativity towards the GCPH......... I had one with the Underwood Mods and it is no way bright. What cartridge is he using and what load setting? Also, as mentioned above VTA problem?

The brightness you are talking about is probably because your system overemphasize the region 2 to 5 khz. Lots of us have the same problem with a great deal of available recordings. Try buy a Loki or invest in some digital processing to find out where your problem is. Fulle agree with eric above. Just bought an old pair of PMC OB1 speakers. 3-way with dome midrange to 3,5 khz. Very nice and detailed sund after some digital room treatment. Suddenly I can play the latest Van Morrison without hurting my ears too much from his (in this recording) extremely nasal voice (probably created in the mixing).

You could buy a better cable 
detail and more warmth Cardas a Clear reflection great combination try this on the interconnects ,also your fuses stock fuses are cheap gritty bright zinc fuses 
buy a quality fuse the synergistic research blue are still at 30 % off
vh Audio also has in slow blow only 
the Hifi tuning copper fuses I replaced all m6 fuses a a Huge improvement is much more natural sounding as well as detail ,seperation but need 150-200 to fully settle in  synergistic says up to300 hrs to full refinement ,also a nice heavy quality power cord will warm up the signal but at least $600 plus for a good qualityparts with copper gold connections like furutech