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.
danto
Krell in general is bright. Not shocked it is the amp.  At 25 years old, all sorts of things could be deteriorating including the caps in the power supply.  You could take the Krell in for a good refurbishing and that might solve your problem.  Alternatively, a new amp will work.  

Lots of choices.  If the Marantz sounded good, Marantz has a series of very good integrated amps that are modestly priced that will likely deliver on what you want/need.  

The new Marantz Model 30 is $2500.  Alternatively, a used PM 14s1 would be wonderful.  I would have to check if the Model 30 is made in China, the PM14s1 was made in Japan.  

If the Marantz was better but you still wanted more in terms of brightness, I would look at Musical Fidelity if made in Taiwan (not part of China, sort of) is Okay.  The M6si is a brilliant integrated amp.  

For made in the USA, the PS Audio Stellar Strata would likely be a good option and PS Audio will take your Krell as is on trade vs. it.  

I am sure there are others that will work wonderfully.  Good luck
I had an old Mark Levinson amp that I bought new and re capped after 20 years and thought it sounded OK until I replaced it and realized it didn't sound OK.  It was dull and muffled and slow,  I went to a class D amp which was energetic and a bit bright but ran circles around the ML and now replaced that with a class A, and now it's just right.

SPEAKERS!! Some brands and dealers can let you try for certain days. I would try speakers first. Happy listening!! :) 
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