sharp and piercing high pitch /frequency coming out from Harbeth C7

Thank you all for your advice. However, I tried a more powerful Amp with 300 W per channel, the frequency is stronger. I also brought the speakers to another audio shop for testing. The same tracks with the sharp freqency happened on the Sonus Faber speakers too. But the sharp frequency was lessen by the high end speaker cable with filtering so I upgraded my cables too.

I avoid turning on the volume too loud, like just turing it not over "12:00 o’clock". I agree that It might be the power supply and the electricity fuse..... and also the placement of the speakers. I have moved them and they sound better now.

Speakers > amps > CD
Are you sure it's not the CD source?

whats the track?

if you switched amps and speakers and the sound is still there - then it may be your source, or even cables, if its some kind of emi (airborne noise pollution captured by rca cabling)

One other thought -- there are bad recordings. Sometimes the original master is done using microphones that have their own frequency response anomalies, or the engineer messes with the frequency response -- perhaps because the studio monitors had a dip where your speakers do not -- or due to a number of other reasons.

The problem is that once the recording is released, you as listener cannot do anything to change what is on the CD. The problem with buying a pair of speakers that fix a specific bad recording is that they will then apply the same "fix" to all of your good recordings. And, that "fix" may not work for other bad recordings that have different problems.

I know it can be very frustrating to have a favorite performance that has been poorly recorded, but life isn’t fair. The one possible solution is to buy a frequency equalizer for those situations and see if that helps improve things.