This is a Denon DCM-390 CD player with a 5-disc automatic loading system. I have tested the RCA line out, the headphone jack and all five (5) disc trays and all of them are in perfect working order. The sound is crisp, clean and smooth. The unit switches between discs quickly and without any issue. All the buttons work perfectly. I would highly recommend this to any audio enthusiast looking for a high-quality, reliable multiple disc CD player & changer.