If you are looking for a replacement and want to go with an old school stereo receiver, I'd suggest Yamaha. Fortunately, your Klipsch are pretty efficient, so you have no concerns of not having adequate power. Note that the least expensive option has buttons instead of knobs for the controls (it is not obvious since Yamaha uses rectangular knobs). If you want controls, the R-S300 at $180 is what you want.
https://www.accessories4less.com/make-a-store/category/stereoreceivers/home-audio/receivers-amps/stereo-receivers/1.html?brand_f[]=YAMAHA
Note that these are reconditioned units, but many of us have had excellent experiences with getting like new gear on the cheap. The few that have had problems have established that Accessories4Less took care of things in a fair and professional manner.
However, once you decide what you want, check Amazon. Sometimes they will have an open box return (with full warranty) at the same or better price.