Help! My system is very bright it hurts my ear

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?

Thanks for pointing that out, Lowrider. Its significance, though, is just that the OP is probably having to use the volume control at fairly low settings within its range (at least with the Aragon amp, when used singly), but at settings that I suspect are not unreasonably low.

The 250mv and 2.5v numbers mean that with the volume control at max the preamp’s output will be 10x greater than its input, which is a gain of 20 db. That is significantly more gain than is generally ideal for use with most digital sources, but given the average sensitivity of the Aragon amp (1.68 volts input for full power), and its 200W rating into 8 ohms, and the medium sensitivity of the speakers (89 db, 6 ohm impedance), and the fact that the system is described as being in a living room with a 20 foot ceiling (meaning that the room is probably fairly large), would seem likely to be within reason. As I indicated earlier, though, I couldn’t find specs on the SE-40 amp.

Best regards,
-- Al

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.

Regarding Bel Canto c5i, I would just say it is very good, quite top notch, as I described and might solve the problem in a fairly straightforward manner.

I've been listening to my second system in our family room that it is in more than ever since acquiring it in fall of last year.  It was a demo unit from a dealer here on Agon and cost <$1000 which is a steal for all you get.  

It is a true digital amplifier ie analog inputs are converted to digital internally and processed similar to straight digital inputs.   Amplifier is recent generation Class D Icepower which enables the output from a small package.    

Its only limitation I would cite is it is only 60 watts but that  is enough to drive most speakers very well to good volume.   It does very well with my Dynaudios which are notorious power and current loving speakers.   Very smooth and non fatiguing with those which is not necessarily the case with all good quality amps that are up to the task.

Can't go wrong to try IMHO if putting out the cash needed is not a problem.

I also run 500w/ch Bel CAnto ref1000m amps in my main bigger system.   I added the c5i based on my satisfaction with those prior.

Lot of good ideas here, but I would start with $20. I use the trick in my system for exactly this purpose.

Buy a cheap component to act as a filter to attenuate high frequencies, known to techies as a low pass filter. Fortunately, these are readily available as plug and play components, if you know where to look.

What you have to do is pervert a cheap signal isolation transformer, which is cheap because it rolls off the high frequencies, to use as a filter. You want it precisely because of this "defect", which would be a problem in many systems - but that’s the whole point in yours. The fact that it also works to isolate ground faults is just a bonus. I use really cheap transformers ($20 for a stereo pair - the ones I use are called 1st Source GL-100 Ground Loop Isolator - and - heresy alert - it’s for car audio) to tame the brightness of my digital front end (and no, it's not a cheap one). They come with RCA connectors, so they just insert between components, with or without interconnect.

You can daisy chain them for added effect.

Cables are another very good way to tune a system. What tends to cost money in cabling is good transmission of the treble information, which is exactly what you don’t want. So cheaper is probably more effective IN YOUR SYSTEM.

What you want, for your system, are high capacitance cables (thin coax) for interconnect, and low capacitance well-separated conductors for the speakers. That specification comes directly from Maxwell’s Equations - it’s physics, not opinion. Cheaper is probably better IN YOUR SYSTEM.

You might also try some carpeting or fabric wall hangings. I use two Persian carpets on the walls - decorative and effective.

Finally, you may be hearing the electronics. One possibility is the nasty brightness of cheap capacitors in the signal path, especially electrolytics, especially if they have been subjected to a hot environment. That requires surgery on your components, but is well worth it. I have no stock electronics anywhere in my system, other than the cartridge. But that’s a more extreme solution. Try the cheap tricks first.

Your preamp has 5 band tone controls.  What effect do they have on your situation?