New McIntosh system problem... need advice

I've just assembled a new Mcintosh system consisting of a C220 and and MC352. I was replacing my old Arcam alpha 7 integrated amp, which has served me well, in preparation for upgrading my B&W DM602 speakers to something larger (probably B&W 703 or 804). I have kept my Arcam alpha 9 CDP.

My problem is that I don't feel the extra $6000 of amplification has actually improved my sound. The midrange, and especially low-range frequencies definitely have more weight and richness, but the higher frequencies are really lacking. In comparison with my Arcam amp, there is very little detail or clarity in the highs. This deficit is as dramatic as the improvements in the lows.

Does anyone think think this is typical? Is this the "tube sound?" I'm using the same cables when I A/B with the Arcam amp, so it's hard to imagine the problem lies there. Could I have defective gear? I bought it gently used, so I can't really exchange it. I would love to get some input on others' experience with these components, and also advice on which of the two amps might be more responsible for the problem.

You may want to consider changing to a fresh set of tubes
..Its possible the person who sold to you sold them at the end of the tube life>>>That would be my first assumption...A fresh set of tubes would be a good idea anyway...
AS STATED INPREP OF UPGRADING YOUR SPEAKERS, Your mini moniters will only dig so deep, with a frequency responce of 52hz to 20khz(manufacture rated) they are a poor match for your Mcintosh equip. Your new pre and power amp will strut its stuff when properly matched to full range speakers
give it time.
Your ears need to adjust to a new sound. I would agree with the buying of a new set of tubes.
I also found using a Mac pre and amp together was too warm for my source and speakers.
more bass can make treble appear softer. give it time to adjust to the new sound and if you don't adjust to it, move on to something else. I am not sure upgrading to 703 or 804 will solve the issue completely. If you won't adapt to new sound, Mcintosh is probably not for you.
I'd strongly echo Thorman on tubes--not only fresh ones, but 12ax7s (that's what your c220 uses I believe) that will give you more of the highs you feel are missing. For a good run-down on tubes and their sound, google Joe's Tube Lore. Not everyone agrees with Joe Rosen's take on tubes, but I've found it to be a very reliable summary of the sonic characteristics of 12ax7s and 5751s. They can make a huge difference, and I say that as someone who's dubious about most of the claims made about cables and ICs.
..that's why it is so important to audition the component in your system to hear if it really is an improvement. Obama won on the subject of change but never spelled out what that change would be. ..maybe good, maybe not...
I agree with changing pre tubes to start.I really like the older Mullard long plate 12ax7s and 7025s.I didnt like the sound of my 402 with a Mac preamp.You might also add a few makers to your short list on speaker replacement..Dynaudio,Focal.Im guessing its your speakers
He spelled out quite clearly what the change will be. Read the news and be thankful!
If your Arcam has pre-outs and main-ins, then you can use its preamp output with the Mac amp, and the Mac preamp with the Arcam amp. Might give you an idea what each of your new components sound like individually.

Second, you might play around with a couple of different output taps on the amp.

And I'll second other's advice about giving it some time . . . when you've spend a pile of hard-earned cash new electronics, mental expectations can be tricky to sort through. But on the other hand . . . if you don't like it, then you don't like it. McIntosh is very fine equipment, and their manufacturing quality is definately better than what you get from Arcam . . . but that doesn't mean that at the end of the day, YOU have to like it better.

At the very least, Mac stuff holds its value very well . . . so I wouldn't regret your purchase.
The advice I read the most here is give it time and try new tubes. I am a long time McIntosh owner and just recently sold a MC352 in favor of a 402. That is a great amp, and does most things well. No amp does it all well, hence the audio industry. In addition to the afore mentioned advice, which is probably the best solution. I would add one more thing you might try. Try re-adjusting your speakers. You mention added mid and bass and that is having an overall effect on the room acoustics. Maybe re-aim them to your ear and see if you can regain or discover a new voice for the highs. You have a great front end give it time. Best luck and listening.
I think what you're hearing is primarily the McIntosh sound. It is more laid back and in a way less detailed. At least at first it seems less detailed then later it seems normal, like real music is supposed to sound. If you have trouble with being bothered by treble and harshness the McIntosh effectively takes care of that. For some people it's a less detailed sound and other, such as myself, it's a great sound, reminiscent of the analog of old.
It should be. No power conditioners. Also if you have a source with a volume control or passive volume control,I would try a the signal direct into the amp, skipping the c220. I have an MC402, which is very similar to yours, and it sounds great, no problem with the highs.
I too owned the C220 and MC352 combination with B&W speakers. I love the musicality of McIntosh equipment but wasn't hearing quite enough detail / clarity for my taste. My solution was to upgrade to the C2300 pre-amp, and I now couldn't be happier.
Try a Mac C41,C42 or C46 and see what happens, i think you will be surprised
Wow, lots of great advice. Thanks! I'll definitely look into some new tubes. The previous owner estimated less than 200 hrs on the c220, so I didn't think about it, but who knows. It's true, I'm definitely used to a more detailed sound from the Arcam, even though I can now see other things I was missing. I do have a B&W subwoofer hooked up, too, so I can appreciate the added low-end I'm getting. Does anyone have suggestions for other preamps that might pair well with the MC352 in terms of extending the highs and brightening it up a little?

(note the username change)
Solid state Mcintosh would be the next logical step in that direction. C45 or something in recent years. The tube sound I think is what you are getting aquainted with. I would just give it time. After all the thing that we "audiophilaic inflicted" usually want is,different sound.
Give it time and you may end up adjusting and realizing you like it better. If not as mentioned you should beable to recapture most of your investment with Mcintosh.
The good thing about Mcintosh preamps is you have tone controls.