YAMAHA CR-840 60W NATURAL SOUND STEREO RECEIVER tested The CR-840 has a built-in AUTO-DX circuit that monitors the signal strength and amount of interference present.  If needed it will automatically switch to the DX Mode IF Stage to increase the selectivity to 83dB. Yamaha CR-840 Meters It also has continuously variable loudness control which means that the frequency balance and volume are adjusted simultaneously to compensate for the ear’s insensitivity to high and low frequencies at low volume settings. So, a natural-sounding balance is maintained regardless of volume level. Tested with Dynaco A25 speakers ( on separate sale ) and it Rocked... I have sold alot of high end Audio gear Meet in Alexandria VA near Fort Belvoir