Adcom a weak link?

if you're asking as a general matter whether upgrading your amp will make a significant difference, i think most  would agree that it does. i never had the 7400, but i had the 5400 (which i believe is the same series and general architecture) as well as the 545 and 555mkii (which was very good). the 5400 was okay but (as others have opined) not as transparent or detailed as my (comparably situated) parasound hca, acurus or b&k.

And, can I ask, what speakers are you using/considering? Also, is it a small or large room? Do you want it loud or are just listening and relaxing?

FYI- The speakers are Infinite Slope .6 and Silverline Minuet. The bedroom is approx 16x14 with speakers on the 16' wall. I listen at low to moderate volume while relaxing, reading, etc. 

Are you using both pairs at the same time? or Alternating?
The Infinite Slope, by a quick Google, seem to be a bit on the vintage side age-wise.
Like I said, if you get Musical Design to upgrade some of the internals, I think you should be able to get as much sound definition as possible, for as little cost. By doing that, then I would think that the Adcom wouldn't be a weak link.
  

I alternate between speakers. The Infinite Slope give a pretty detailed presentation and the Minuets are great little speakers, too. I can see trying a pair of DeCapo or something similar in the future.

If I decide to replace the amplifier, I'll keep the Adcom for home theater, etc. But before I spend very much I'll consider an integrated.

The Nuprime IDA8 is interesting to me because of the form factor and because they will offer a wifi dongle in the future. That will move me toward hires Tidal playback in that room, which I like.

Thanks for the ideas, I ordered a Fiio dac ($14)to use between my Roku/tv and preamp to see if I can hear a difference. I can always use it elsewhere later.

Gary