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.
Clean the contacts on your speaker cable ,interconnects and power cable. I had the same problem . It worked for me . Testing your hearing is another option. No offense intended 
Get ROON and use the parametric equalizer and the speaker set up tools to make some adjustments 
@alfa100 cleaning the contacts is a good idea. I know that the hearing in my left year is somewhat diminished (many years of driving convertibles), but my wife confirmed the audio issues and, I promise, she is not one to humor me. 
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Danto. Please let us know if cleaning the contacts helped