I'm looking for a matching amplifier to drive Q Acoustics 3050i floorstanders. Have set aside a limited budget of 25K for the amp while being open for used stuff. I have an Rpi+Allo source. I was suggested that Yamaha A-S500 would good for my needs but it seems to be discontinued. A dealer in Hyderabad suggested Yamaha RS-500 (Stereo Receiver) which was in stock. Besides the FM Radio, he couldn't say the difference between A-S500 and R-S500. Any suggestions on this?