You definitely don’t need any more preamp gain with your amp an speakers.
Your Naka PA-5 needs only 1.4v in for full 100w output and it’s 75kohm input impedance. With today’s sources all you’ll need is a passive preamp, especially with your 98db efficient Klipsch Cornwalls.
You’ll really only need the $49 Schiit Sys passive preamp a great match for your PA-5, it’ll work great with what you have. https://www.schiit.com/products/sys
Nelson Pass,
We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.
Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.
Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.
What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.
And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.
Or if you want to add some tube warmth "colouration", the Schiit Saga+ at $399 has a tube running at unity gain which is also an option. And has remote control. https://www.schiit.com/products/saga-2
Cheers George