Why does my system now have shrill top end.


The equipment in my system (listed below) has not changed but I now find on both CD and Vinyl a high end shrillness to the sound (treble is very harsh) that has become very annoying, especially at high volume levels. I have no idea why this happened all of a sudden.

Endevour E-3
Pass 30.8
Pass XP 20
Esoteric K01x
Linn LP12 (Ortofon Black cartridge)
Linn Linto Phono Preamp
PS Audio P5 (Amp plugged in directly to wall)
JL Audio F112 v2 sub
OCOS Speaker cable (15 feet)
Pass XLR interconnect (Preamp to Amp)
Harmonic Technology Cable Magic Link (not current version). RCA termination

Any ideas?
proacman
Moderators please remove all the insulting posts, perhaps kosst_amojan himself, from this site. He continuously insults and brings down the enjoyment and civility of this once fine audiogon community. This cannot continue without many of the long time and civil members opting out of these forums. 
I second what @jea48 said: check, or have your electrician check, the connections in the panel. Not just on the circuit feeding your system, but every connection: hot, neutral and ground for every breaker. You may even consider reseating all the breakers. (Please stay far away from the lines coming in from outside. If you don’t understand what I’m saying, please hire an electrician or ask lots of questions)
I know that loose connections can add significant noise to the electrical system.

Definitely try the amp swap too. Give us more data points!

Good luck!
@almarg 
I'm aware that some cables are designed to be highly reactive. I seriously doubt any cable could cause a sudden onset of an undesirable characteristic. A cable may attenuate the problem, but not cure it. 
If I was suddenly having this problem the first thing I'd look for is DC on the outputs. Next I'd verify rail voltage on the power supply and give a good visual inspection of all the discreet components. I'd do the basics to rule out the amp because that's the most likely culprit.