Likely culprit for harshness at higher volumes?

Thanks guys.

The KEF C75 (4ohm) is rated for at least 150W I think. I think the Adcom GFA-5400 is rated for 150W/ch for 8ohm, 200W/ch for 4ohm.

I'm waiting for Monster MC 200I-2M interconnect cables (for pre-amp to amp) to arrive; hope these are okay. :) I didn't plan to change the Toslink yet. I am also planning to get some (better?) 16 gauge speaker wire from Radio Shack (I was thinking about Monster XPMS but it's 3x the price and not sure if it's any better).

The typical CD's include Jane Monheit "Never Never Land", Joe Pass "Virtuoso" and various Diane Krall; also some Burrell, Coltrane -- usual vocal/jazz stuff I guess.

I was wondering if it was the KEF's since the AVM2 and GFA-5400 seems to have good reviews. I only have KEF Q10's to try but I can see what happens. I'll also try using analog from CD to pre-amp. I was only using the digital connection because I was assuming that the AVM2 DAC's are better than the Sony's.

2 easy things to try and I'll report back later. Thanks for the help. Open for any other thoughts as well.

Saru,

It is obviously not your choice of music. I doubt it is the amp or preamp.

Therefore that leaves speakers or a jittery digital input.

One further possibility is your room, if you have tile on the floor and fairly reflective surfaces then this could be the issue - an issue that gets worse as you increase the volume.

I'm going to go out on a limb and say that it's probably your speakers or the room. The cables you describe should work just fine. I recently compared a set of $2,000 Nordost cables to a $7 pair of hardware store cables and certainly couldn't tell $1,993 worth of difference, at least for my system that I have about $5,000 in for the main stereo components. Cables make small difference and what you're describing sound like they are more significant in scale. Keep in mind that there are many members on the forum that have systems where cables might make a significant sound difference, but I don't think it applies to you and me. I'd suggest going with something like Blue Jean cables if you want something that's respected and affordable.

I would try decent (not necessarily expensive) analog cables instead of the Toslink first.

It's your speakers.

From a review: "The overall sound can get a little grainy if pushed too hard"