Panasonic AG-8700 S-VHS VCR: XLR to RCA
 

I'm using this deck to digitize old cassettes and I wanted to make the audio sound better. So I thought that taking the audio from the XLR outputs would be better, as this is the professional output. So I got myself an XLR to RCA adapter, but to my surprise no audio comes out of the XLR. When I connect the RCA cable to the monitor output, I can hear the audio. What do you think?

Which of the outputs did you use? These decks have two sets of audio outputs (in addition to monitor and headphones). Can't find the manual for this specific one, but I would assume it's similar to the older models. The Hi-fi output only outputs if there is hi-fi audio on the tape. The other one (norm/hi-fi) outputs hi-fi if there is, otherwise normal, but can be forced to normal with a switch on the front panel.

Alternatively you can try the headphone output on the front of the unit.

XLR won't really help unless it's used at both ends, though the monitor out only gives you mono audio (which only matters if you have a tape with hi-fi or linear stereo), . XLR (balanced) will be less suspectible to noise than RCA/Phono (unbalanced), but I don't know how much difference it would make for a VCR.