Best Integrated Amp for KEF Reference 1s Under $5K New or Used

Hi all

New to the forums here. I recently acquired a set of KEF Reference 1s and am running them with a Primaluna Dialog Premium HP Integrated Amp with KT120s installed. Sound is very good but these speakers are apparently quite power hungry so I would like to at least do an in-home trial of another integrated with more power, to see if I am missing out on anything.

So two questions really:

1. Do you think I would benefit from an amp with more power and/or solid-state technology?

2. What integrated amp under $5K new or used would you recommend?

Some more relevant points:
  • I am only considering integrated amps due to space constraints
  • I am absolutely open to buying lightly used equipment
  • I only listen to vinyl and already have a very good Herron Audio standalone phono stage
  • I also listen on headphones so need a very good headphone port
  • I don't need a built in DAC, bluetooth, tone controls, rumble filter or any other bells and whistles
So in summary all I really need is a single line-in connection, built-in headphone amp and volume control.

Thanks in advance.
I own KEF R-500s ($2600 MSRP), and my dealer recommended Hegel H190 integrated amp, 150/250 wpc.  H190 is $4000 new and $3000 used.  He said for KEFs to really dance they need a high current amp.

I bought the H-190 and was amazed by the difference it provided, much more bass and much tighter bass, increased detail in mids and treble.  When I discussed upgrading to the KEF R-11s, he said the Hegel H390s would be the appropriate electronics.  The H390 is $6000 new and ~$4800 used.  Best of luck!
Right now the Anthem STR Integrate has a 20% off sale going on at around $3600.
What type of sound characteristics in a system are most important to you?
What you’re missing is not power, the Ref 1s have a fairly easy impedance curve. What the Prima Lunas lack is clarity and refinement. If you want just integrated, try to get a used Jeff Rowland Continuum S2, which is incredibly good. Don Sachs Pre and KT88 is a screaming steal for what they deliver if you can go separates, they perform at the highest level. Both routes will get you deeper sound stage, more precise imaging, better tonal colors and more definition on transients.
I listen to a lot of rock and pop so big dynamics and soundstage matter a lot.  But I do also listen to quiet music too so clarity and refinement matter as well.

Thanks for the suggestions so far.  That Anthem keeps getting mentioned a lot in various threads.  The Hegel H360 is mentioned a lot too, any thoughts on that?

I'd never heard of Jeff Rowland.  Certainly sounds like the polar extreme of the Primaluna, being Class D solid state.  Intriuging.
The Don Sachs amp has the best dynamics and soundstage I’ve ever heard as well. I’ve auditioned Gryphon, Luxman, Ayre, ARC. An equal contender I forgot to mention is Jadis, i-50 and i-88, there is something magical with Jadis's amps, it was probably the most real instrument color I've heard, you could hear not only the physicality of the instrument, but its material.

Jeff Rowland is a mainstay in high end audio if you look him up. I was absolutely surprised by his class D, changed my whole perspective on the topology. It sounded organic, bold tone with incredibly realistic instrument timbre, and the best part is really deep defined soundstage with inky black background where notes just appear out of no where. It’s also an integrated with oodles of power which fits what you are looking for, definitely worth an audition at the very least.