Hello,
My Aircraft Operating Manual says the A320 'CVR' is powered by the AC ESS Shed Bus and the 'CVR Control' is powered by the DC ESS Shed Bus.
In the Emergency Electrical Configuration early model A320s have these two busses powered until the landing gear is down. Then the 'CVR' and 'CVR Control' would lose electrical power. Later model A320s, as well as the A319 and A321, do not lose power to these busses when the landing gear is down and therefore the 'CVR' and 'CVR Control' would remain powered.
best regards,
Bruce Waddington