Pioneer DVL-700 question

How do I get this thing to output a dolby digital signal? I've tried with an optical cable and with a coax cable (on the few different coax outputs) to my yamaha amp, but my amp only detects prologic come from the player.
The discs I've tried are all AC-3 and I know that my amp auto detects the signals correctly since my DVD player outputs both dolby digital and DTS, and it detects both.

I'm assuming there is some setting I'm missing. The little red 'dolby digital' light comes on the player, so it knows what it is.

I believe I can set that on my amp, I'll give it a try. I recently downloaded a copy of the manual from the internet, and after reading it I'm not so sure that the DVL-700 will actually output an AC-3 signal from a laserdisc. The manual seems to say that its only DVDs that take advantage of the dolby digital outputs. I have tested a DVD with the player and sure enough my amp detects the dolby digital signal.
Can anybody confirm that the DVL-700 only outputs AC-3 for DVDs?