System very bright after adding Mcintosh amp

So, I recently added a Mcintosh MC7205 amp I purchased off of audiogon to my system. Im using a Marantz Sr8002 as the pre/pro and have b&w speakers (683 fronts, htm61 center, and 686 rears)

Anyway, I've noticed that recently the whole system is abrasively bright. It sounds like whatever I am playing is a poor-quality mp3 and hits those high-end pitches that almost seem to pierce your ears.

I've re-run audessy since adding the amp but didn't notice and improvement.

Any thoughts or suggestions?

What amp were you using prior to the 7205? I owned a 7205 and used mainly for center and surrounds at the end of my time with it. I was using a MC352 for the fronts, but prior to that the 7205 was driving all 5 channels and they were Infinity Kappa 7's, a bright speaker. I can't recall it being overly bright or poor quality. I will add that the MC352 had an entirely different sound. One I attribute to the power but also the autoformers.But if you are getting a bright sound of B&W speakers, I would question that particular amp. Do you have a McIntosh service center in your area that you can have it checked out?
It's kind of odd to hear about a McIntosh amp sounding bright or brittle, there reputation is somewhat opposite. I had a similar experience with a Levenson amp that was not known for being bright either, changing the power cord and interconnect solved the problem. Have you tried different cables, cords, ect? It could be that your amp is just more revealing of other things in your system.
As with all things involved with audio it may be simple or could be something further down the chain. I had a few amps from the mid to late 90's, Mc 300 and Mc 500 in that era were warmer sounding than current crop. If your 7205 is bright something is off. I used the 4 ohm tap with best results with any speaker/ amp combo, try that if not already on 4 ohm tap. Another cause could be when you switched out could the speaker wires became loose or became inverted at the neg/pos terminals?
..I was going to add maybe you're having a problem with your speakers/crossovers.
Overkill amp ??
I'm assuming this is auto former coupled output. Are you sure you are connected to 0 and 4 or 8 ohms?
" Overkill amp?? " LOL.
Well tried playing with a few more settings and the Level controls on the back of the amp and still not much luck.

I can try different interconnects, but thinking I may just call MAC on Monday.
If you plan to send it in you may also try, they are all. McIntosh people over there and may have a quicker turn around. But you may try different cables and resolve your issue. But I would suggest calling both McIntosh and audioclassics and see what they tell you.
I'll hazard a guess as to why the B&W's sound bright with the McIntosh amplification: Perhaps the B&W's have a varied impedance, and the due to the McIntosh's use of auto-formers, the dBW output of the McIntosh amps is higher into higher impedance at the B&W's higher frequency response, and the dBW output of the McIntosh amps are lower into the B&W's lower impedance at lower frequencies?
Unsound-- that's a good thought as the b&ws do have varried impedance, but unless I'm mistaken, I don't believe the mc7205 has the auto transformers. I don't think MAC introduced those until the mc205/207
The MC7205 does not have autoformers and neither do the MC205/207. They have only made one amp with more than two channels that uses autoformers and that the 3 Channel MC303. 5 Autoformers for one wouldn't fit and the amp would require a forklift to move. Jastone you only have a 4 or 8 selection to choose from and a input variation selection for each channel on the 7205. But I seriously doubt these settings are creating the issue you seem to be experiencing. Were you able to contact Mc or Audioclassics today?
Theo-- had a few unexpected things pop up at work Monday and today so didn't have much free time. Hoping to get in contact with them tomorrow...
Stupid jobs! Always get in the way of what really matters:) Oh that money thing.
If the Mack amp is bright? Mr.Ed really does talk .Its the cables