The Marantz Model 15 Amp

I don't think it will be that much different then the receiver you already have. You don’t need the power of that amp (or your receiver for that mater) with any of the Klipsch heritage line.

If it was me I’d find a nice low powered Tube amp, personally I’m not a fan of SS with Klipsch heritage speakers.

But if you own it, try it, you may get different results . And if you already have the receiver then why do you need an amp that you will also need a preamp for? using the receiver as a preamp is not ideal either as most preamp sections of revivers were not as good as separate preamps.

How fresh is the rebuild? Old solid-state gear will lose its smoothness when the caps dry out. Why bother with old gear, there is very good new stuff out there that will sound better. Rogue and Musical Fidelity come to mind. 

I have a Cary SLI-80 tuber. Sounds great. Just love the older Marantz stuff which keeps my Mancave cooler in the Summer. Cary in the Winter. Maybe I’ll send the 15 through my 2226 preamp? What do you think?