What is the cause of my sibilance problem?

Gallaine, I've made a different experience. I listen to a lot of vocals, male and female and I've got the problem of sibilants perfectly licked, inspite of having very resolving tweeters,( plasma) which go up to where the bats hear. With me it was the front end and I suggest, that Gallaine experiment with that.
Cheers

I guess that it is high frequency oscillation and/or ringing riding on the music waveform caused by RFI being picked up/reflected back into components by too many cables and wires. Also, so many connections to component input and output stages with so many series and parallel input and output stage circuits terminated could be setting up a "tuned circuit", ringing like mad or even picking up RFI at frequencies all over the spectrum. I would simplify the wiring and connection paths and pay close attention to a true single point grounding as well as common shielding and shield current direction.

Sol322 - The cones I use on the transport are the Mapleshade Triplepoints and on the DAC and preamp I use Mapleshade Surefoot cones. The Triplepoints have three small points instead of a flat surface where the components comes in contact with it. For each component the cones are arrayed in a triangular pattern with the "points" "down" (one cone along the rear and two along the front). It certainly is easy enough to try different configurations and I think I'll experiment tonight (provided I get home early enough). Incidently, the problem occurs with or without the cones installed.

Detlof - While I'm not ruling out the front-end I had a Roksan Caspian CD Player that only started exhibiting the problem after several changes to my system. There-in lies the problem. I don't know if it was something I did or if the problem was always there just hidden.

Nightdoggy - I must admit to some confusion. While I think I understand the gist of your post you lost me in the details. My system does in deed have alot of wires. But I don't think there is any possibility of simplifying without removing components. Perhaps one day I'll have the room and budget for separate HT and two-channel.

There is a possibility that the culprit is the preamp. It is the one component that I haven't experimented with. And given that the problem is experienced both with headphones and loudspeakers it seems to me that eliminates the power amp (though certainly has other failings). Another interesting thing is that the sibilance is present at all volume levels - well, I haven't actually tried all since I live in an apartment and don't want to upset the neighbors. And, the sibilance is greatly reduced to non-existent with movie playback - maybe a good experiment would be to play a movie in direct stereo mode and see if the sibilance is worse or better than Dolby Digital mode.

Gallaine, after what you say now, I doubt that the front end could be the culprit. Nightdoggy might indeed have a point, with RFI being the culprit. Then also a bad solder joint or a loose connection somewhere comes to mind, but then I think you said that you had switched and experimented with cables. Experimenting with your preamp is probably your next best bet. I wish you the best of luck. The fight against this kind of nasties can be very exasperating. Please let us know of your progress!
Regards,

Check to see if the problem persists w/o DAC. If it does not then you have jitter. See Sonic Frontiers for a solution.