You may have noticed that some industrial S-VHS decks, such as Panasonic’s AG-1970, AG-1980’s and
JVC’s S-365, use line-level RCA phono jacks, whereas higher end models use the XLR 3-pin connections. The same holds true for Panasonic digital
video mixers, such as the Panasonic MX-30 which uses RCA jacks, while the Panasonic MX-50 uses XLR or RCA jacks.
You can purchase plug adapters, unfortunately these adapters don’t completely solve interconnection problem. The RCA type jacks are for unbalanced -10 dB high impedance signal, while the XLR connectors are usually balanced +4 dB low impedance line level signals. Therefore you will need more than just a plug adapter for maintaining the integrity of your audio signals.
There are various companies that produce devices for matching these audio interfaces. This will allow you to convert from an RCA -10 dB unbalanced line to a XLR +4 dB balanced line or vice-versa.
What about plugging in a low-impedance microphone into one of the MX-50’s XLR inputs? Unfortunately, this can’t be accomplished even though the connectors match. In professional audio interfacing, both line-level signals and microphone-level signals use the XLR connections. The XLR line-level is a +4 dB signal and the XLR microphone-level is a -40 dB to -60 dB signal. You will need to use a microphone pre-amplifier to bring it up to line-level.