Likely culprit for harshness at higher volumes?

Saru - I read through the manual for your pre-amp and didn't see anything like what I was referring to. On my truck subwoofer amp and also some of the amps in the audio system at my church have adjustments for the input sensitivity that can really change the way things sound. I think some seperates have this type of adjustments, but not all. I was thinking that you might have things oversensitive and amplifying something in the digital recordings.

You might actually try allowing your pre-amp to do some processing rather than bypassinge everything. On my Integra 50.1 receiver I generally listen in direct mode when I'm in audiophile mode, but for some recordings it simply sounds better in stereo mode where the signal gets processed a bit. It may be similar for your system but for different reasons.

I highly doubt that you'll hear much if any difference from any cable swaps you make unless you are currently using a damaged cable currently or you're getting a lot of interference in an unshielded cable.

1) CDs. Some are mastered horribly bright
2) Room. Too much reverberation at high frequencies
3) Speakers.

Glad some small tweaks could elp out.
you could experiment with the Ferrite, try taking a pair off an interconnect (a tiny screwdriver can pop up the clips if they are like the old ones I still use, bought them 20 years ago.. and have moved them around and around an all sorts of stuff. I must own two dozen of them))
And try one on the CD powercord.(or if new Radio Shack anytime soon, get one for the CD powercord.
If i was you, i would look foor a cheap used Adcom 315 power conditioner here . Or some other small conditioner, to use just for the CD player and preamp.
Not more than $100 used.

Given that your preamp has a headphone jack, my suggestion is that before going much further you invest in a pair of headphones. Considering the number of variables and possibilities that have been cited, I think that comparing results between headphones and speakers would be very useful in distinguishing between source material or front-end issues, and room/speaker/amplifier issues (despite the fact that headphone listening is a fundamentally different experience than listening via speakers).

A good fairly low priced choice would be the $84 Sony MDR-7506, which is widely respected within its price range. I have a pair that I use for non-critical purposes, primarily for monitoring while doing amateur videography and voice recording, and I've been pleased with it, especially considering the price. I haven't tried it in my main system, though.

04-22-11: Meiwan
At higher volumes you may be noticing harshness in your system that you don't at lower volumes (even though it's there).

This is an important point to keep in mind. As volume increases, the sensitivity of our ears to high and low frequencies increases, relative to their sensitivity to mid-frequencies. That is known as the Fletcher-Munson Effect.

Regards,
-- Al

My best guess is it is the CD player and maybe amp. I doubt it is the speakers or room. Higher order harmonics are not genrrated by the room. You can take steps to improve room acoustics, but that is more like icing on the cake and no way to fix bad equipment. When i first started with CD, my first impresion on 90% of CDs was things were way too harsh at even moderate volume levels . I found the only real way to improve things was to get CD players with way better digital filters and analog stages. I made the natural progerssion with better players and noticed a big improvement with each step. I went from Pioneer BPC, to Theta, to Krell, to Wadia, and back to Krell. :)
you might look for any reviews on your amp to see how it does higher order harmonic distortion. I know Adcom only really made one amp that was even close to "high end", that being the model designed by Nelson Pass. The rest of Adcom amps are strongly mid-fi and not much more than BPC. (sorry to say)