Help! My system is very bright it hurts my ear

I agree with losing the biamp for now; simplify your system and use one amp until you stop the offending brightness.
 
Then address treating your room for best sound. Can you answer these questions, please...
- What are the dimensions of the room? We only know that it's a high ceiling.
- Do you have carpeting or bare floors?
- Do you have bare walls? You'll need to have wall hangings or furniture against the walls so that sound waves don't bounce around.
- How far away from the speakers is your listening position?
- Have you done any reading about how to use acoustic room treatments?

Do you have a source other than your CD player, such as a tuner or TT? You have a good CDP, but Amperex tubes can have an "edge" or sound bright with some CDs.

Also, if the gain of the CDP is too high for the preamp, it will sound bright.

@almarg,
Al, the Input Sensitivity of the Macintosh c40 preamp is 250mV (at the time of 2.5V Output power) (50mV IHF).
Input impedance is 22kohm. Interconnects are unknown.
How does this match with a CDP having an Output of 2.2 Volts?

@fatgosil, there are ways to improve the acoustics of your room. Use several throw rugs in your listening area, or an oriental rug.
You need wall-hangings, or better yet, some acoustic panels for sound absorption.
Don't try to fill the entire room with sound. If you haven't already, create a living space close to your system. How far away is your current listening area from the speakers?

Take a look at the Virtual Systems section and see how other members have treated their rooms. Those with systems in the living room (myself included), use rugs, drapes or curtains, plants, bookshelves to absorb standing waves which include mid and high frequencies. I have a tapestry hanging on the wall behind me and it helped reduce the brightness from my system.

Thanks for the reply, Al. This difference in gain shows that the OP's passive biamp is not an optimal setup. All the more reason to use one amp during this troubleshooting process as you stated earlier.

terry, don’t you think it would be better to find the root cause of the problem, rather than apply band-aids or work-arounds?

  @onhwy61, good question.
@fatgosil , are you aware of these tone controls and how to use them?

@fatgosil,
any progress yet on finding or fixing the brightness issue?