Is it my amp or my speakers?

I've been dissatisfied with my system of late--wanting a little more brightness and color--and can't decide if it's the amp or the speakers, or both. Here's the set-up:
  • Krell KAV-300i integrated
  • Cyrus CD-T
  • Schiit Gungnir DAC
  • Tekton Lore speakers
The Krell was a hand-me-down (!); everything else was purchased new. The amp had some overpriced work done to it a few years back and I'm wondering if the workmanship is starting to show, or possibly its age (~25 years, I'm guessing). Or, are the amp and speakers mismatched?I can afford to invest about $3K in the system, but am unsure where best to put it.Any thoughts/advice would be much appreciated.
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Danto. Please let us know if cleaning the contacts helped 
@alfa100 Sorry to report that cleaning the contacts made no difference (they really weren't dirty). Thanks for the idea, though.
I wouldn't go so far as to call your Krell "garbage", but it's not very good.  You could easily find something better.  You could get a really nice integrated for what you have budgeted.