The NAD 3140 Stereo Integrated Amplifier came onto the market circa '80.
Features such as infrasonic and ultrasonic filters, current "dumping", soft clipping, bridged operation and a dual power supply, put NAD's international design team beyond the convention at the time.
Above listed electrolytic capacitors need to be replaced.
After a clean-up (with Isopropyl) and BIAS adjustment the Amp will be as good as new.