Questions about Yamaha Bd-S681

The BD-S681 has both analogue RCA audio outputs (left + right) and digital outputs optical and RCA. Check which of these connections are available on your amplifier/preamplifier. If there are several to choose from, the digital ones are preferable. As the unit is designed as a Blu-Ray Disc player, a TV or Yamaha AV Controller software (free from Yamaha website) for tablet/phone may be helpful in setting up. There is also a remote control included in the delivery. In contrast to simple "CD only" players, this unit is not very fast to operate, but its sound is excellent.

According to its own research, this unit supports the following formats via USB storage devices: MP3, WMA, AAC, WAV, FLAC, ALAC, DSDIFF and DSF. Thus, unfortunately, no MP4 files can be played, sorry.

This is only a player. Therefore, the maximum will be a normal headphone via the cinch output. This will feed an AV receiver, a stereo system or similar. What are you looking for? What does the device have to be able to do? And what is the budget?