I noticed brightness/harshness more than usual from my system a couple months back.

Have you tried a cd player or tuner to see if the harshness remains?  I would try that first as it will tell you if there is something not right with your vinyl setup. If there is harshness with other source components, it is either the amp or speakers.  

Could the power to your equipment have changed? Is there something new/different with items plugged into the same electrical circuit, or other circuits? Did the acoustics in your room change? ..ie..moved furniture, floor or wall coverings. Short of removing wax from your ears, your high frequency sensitivity isn’t improving.

Before spending more money on a system you have been satisfied with, get your hearing checked.

If it were me, I would make this a priority.

The options for the change are infinite.  @stereo5 is absolutely correct.  You have got to play detective first.  I have had a single tube weaken, a mid-range with a hiss, caps blown and simple fuses.  Time to play detective. You can't address what you don't know. 

Thanks all...

stereo5 - sending the cartridge away caused me to listen to the CD player. Usually I listen to vinyl only. It is there on cd, certain passages, certain songs.

von - power to the equipment has not changed. Unless it changed at the wall socket. CD, integrated, phono mc all plugged in to the Brick Wall. Always has been. I'll take everything off that see what happens. No changes to the room.

pmm - that's crossed my mind. I should do that! At least it will confirm or dismiss a hearing issue. Google searches tells me as we get older hearing gets more sensitive. Maybe that's just the way it is. I do occasionally find myself listening at lower volumes. Maybe that's a clue. But some music I like louder. Especially my good recordings.

Google searches tells me as we get older hearing gets more sensitive.

I guess that you can find anything with a Google search. Hair cells die preferentially in the high frequency range which reduces our sensitivity to high frequencies. What many of us consider high frequency when listening to music, especially at our age, are frequencies around 12Khz. I believe that aging frequency loss is above this frequency. For some of us we loose much lower frequencies and have issues understanding speech.

Is it true in both channels. If it's just one something probably went bad in one channel. Try switching left to right in one piece at a time and see if it changes channels.

If it's both channels it's tougher but it's your system(which can include room affects).

Good luck.

Class d amps can sound like this if you don't keep them on.

For an easy option, try installing a pair of V-Cap ODAM capacitors in your DAC, preamp or amplifier.  They could help you out for not that much money.  Or you can try Amtrans capacitors for a lot less to see if that makes an impact you are looking for.

Happy Listening.

@oharek Try to figure out if it’s coming out of one speaker or both.

Think back the past few months, have you moved or changed any cable, any components, anything lately? I always go back to checking all connections 1st.

I’ve seen this occur with a damaged interconnect, or a speaker cable connector is not fully seated. As previously noted, start with very simple detective work first.

Unplug everything if you have to and start over. Worth a try before buying anything.  

Your neighbour was doing the laundry 

I think your record or the stylus is worn out and distortion is the consequence.

If you notice this harshness with both sources and many albums, it’s your system. 
It could be power related. One suggested without breaking your bank, if you are using stock power cords, try a good power cord on your amplifier. Don’t need to go crazy. And plug the amp directly into wall outlet. 
Here’s an AudioQuest power cable on USAM. Should work fine on your amp and should tame that harshness a bit. 

From the way you described it seemed to have happened suddenly and it was obvious enough that you noted a time frame. That makes me believe it's likely your system not your ears as the ears would be more gradual over time. But still a good idea to have checked anyways especially if music is playing harsh that could speed up hearing loss. I think stylus last 10k hourish...also maybe a cable was jolted, like it has back out slightly. Perhaps the tracking or balance of your tone arm has moved? I do notice power around my house like appliances, dishwasher laundry seems to change my sound too almost thin like. But agree with everyone here time to play detective. I'm not sure if you said this but do you have tubes? I'm sure if you did you would have already checked that out. But keep us posted we are all curious to find out the source of this. I've put wharfedale and Naim 5si together and it was a shockingly good combo. Nait 5si may not have quite the power a supernait has but the sound signature is very much the same and wharfedales are easy to push. If you end up exploring this option later thought that might be helpful information. 

OP I am sorry to have to inform you, you have early onset audiophilia nervosa.  A psychological condition build up by sub-conscious activity in the imagination.  In its early stage it affects only the music that is your most favourite; other music still sounds as before.  But soon all music starts to be affected, spoiling all your enjoyment of our hobby.

It is unfortunately incurable.

Here is a review. The aluminum tweeter can be what you are describing!

 https://www.theabsolutesound.com/articles/bw-cm6-s2-loudspeaker/

Baring some sort of equipment failure, have you tried repositioning your speakers. Try pulling them further from the wall. Maybe play with toe in a bit. Just a thought after seeing your system photos.

OH, so two things about these speakers:  B&W often sound better BELOW the tweeter.  Also, with metal dome tweeters reduced toe-in is often required.  They resonate hard on axis but a few degrees off they get very smooth.

Of course, ,the room matters,  A very reflective room will turn to harsh mush when you turn up the volume.

I have an occasional day where the planets do not line up as they usually do.  I turn it off and come back in a day or three and everything's all better.  Some will blame it on the electricity, one day or time of day.

oharek 
I am also over 70 years with normal hearing for this age, nothing above 12 K,  and a mild case of tinnitus.  I have a Marantz AV7703 Pre/Pro Tuner in my music/TV room hooked up to various amplifiers, Martin Logan Expression ESL 13A Electrostatic Speakers, and other TV surround speakers.  These Electrostats are very detailed and over time I noticed that on long periods of stereo listening, not TV, I would get fatigued and more sensitive to the upper audio ranges. 
I changed my stereo equipment so that now I am listening to music starting from my computer or DVD player through Denefrips Terminator Dac (R2R) to PS Audio BHK PreAmplifier (Tube and Digital Combination) to Pass Labs 260.8 Mono Amplifiers - A/AB (Analog Sound).   
I now get great detail from the speakers tamed to a wonderfully musical “vinyl” sound.  The brightness/harshness that you noticed, as did I, is completely gone. I still get all the upper-range detail and clarity that I wanted without the irritation. 
Changing your DAC, pre-amp, and amplifiers to the direction of analog sound will help eliminate your hearing problems.  Your system will end up being more enjoyable and satisfying.

Have you changed, or tried changing the DIP switch adjustments on the Rega Phono Pro?

@oharek 

There are times,  mostly in the evening, when electric guitars and saxophones really start to hurt my ears, but that’s only at night. Are you having this problem all the time? How loud do you play your music?  There’s a few things it could be, but it wasn’t happening a week ago, I doubt it’s your equipment.

I am 70 now however this happened to me over 25 years ago, I had a bad cold and ear infection ever since I have suffered mild tinnitus, it is especially evident with 'ssss" , it made me very prone to hearing sibilance. Try listening to instrumental music, if that is not brighter then this could be the cause.  Simple hearing tests will not determine this as no loss of the ability to hear each frequency has occurred.  In my job, working with explosives, I had hearing tests very regularly, the results never changed.

Thanks everyone for all the great information and advice. I will try and respond to some here.

I have unplugged and cleaned all connections. This would eliminate a loose connection somewhere. I have had a loose connection problem before. If I remember correct it was at the cartridge wire connections. This and all other connections is first things I checked.

I did change phono mc dip switch settings. It didn't eliminate what I'm hearing but definitely changed the sound. Not to my liking. 

The room is very small and changing position of speakers is very limited. It's a small bedroom. I have moved the speakers away from and closer to the rear wall. Toed in. Straight out. Best sound for me in this room is 12 inches from the wall straight out. I figured this out way back when I first got them. Wish I could spread them out more but no room.

The stylus is not worn out. Only about 350 hours on it. That was my first thought. It is still under warranty and I sent it to be checked out. It is ok. 

I am leaning towards it not being an equipment malfunction problem. Maybe bright equipment issue but nothing broke. Maybe record pressing issues I never noticed before until now. There are 2 things I have decided to try for now. Have my hearing checked. Get 2 AQ power cords. One for the integrated, one for the cd. Music Direct has the suggested ones on sale 1/2 off. $200 bucks isn't going to break me and they can't hurt, right?

boxcarman - I can relate. I played some records yesterday and all was well.

couriousjim - I listen mostly in the evening. 5pm and on.

On the lighter side...

I have no neighbors close enough for them washing clothes to be a problem.

Is "audiophilia nervosa" a thing? I'm starting to believe it.

Different systems, depending on their emphasis can be really forgiving, or not. This is about the components and interconnects.

iI I were to buy some different interconnects with the hope of fixing the problem you have it would be Cardas. I own some high quality AudioQuest power cords and have tried some interconnects. They are not designed to be forgiving. Cardas are. I encourage you to read about Cardas… their ,owes level are designed to be the most forgiving, and less so as one goes up their product lines.

I highly recommend trying Cardas before AudioQuest. They are much more likely to improve your sound.

I had the same problem a few months ago. It was the ac wall voltage. It was so high one of my amps would shut down. Check your wall voltage with a multimeter. I now have a 20amp variac that allows dialing in the voltage wanted. Going from over 125v to about 110 made an amazing change in sound quality. Less strident and more relaxed. The brightness is gone. 

Thanks and good luck,

aldnorab