Unfortunately, NO.

Laserdiscs have four audio tracks: two hi-fi analog, two PCM digital. The digital output (optical or coax) of a laserdisc player only transmits 2-channel PCM data. To hear the analog tracks, some of which have filmakers' commentary, you have to use the player's analog outputs.

When Dolby Digital showed up on laserdiscs, the space being occupied by one of the analog tracks was used to carry the AC-3 data. The remaining analog track and both digital tracks were left alone for backwards compatibility. Everything that the laser picked up (the video signal and all four audio signals), was RF (radio frequency) modulated and sent to the AC-3 RF output on the back of the player.

An RF demodulator would than strip out all the extraneous signals and send only the AC-3 data to the Dolby Digital decoder. Without this step, you won't get anything useful out of the player's AC-3 RF output. So an RF demodulator is a must. Otherwise, you can use the stereo PCM tracks and listen via PL II. Sounds almost as good as discrete 5.1.

Best,
Sanjay