Multifunctional alcohol dehydrogenase exhibiting NAD(+)-dependent dehydrogenase activities for 2,3-butanediol, ethanol and acetaldehyde, and reductase activities for acetoin (NADH-dependent), and diacetyl and acetaldehyde (independently of whether NADH or NADPH is the reductant). The rate of oxidation of 2,3-butanediol is much higher than for the oxidation of ethanol. Has acetaldehyde dehydrogenase activity leading to acetate formation. May function in the release of excess reducing power in the absence of exogenous hydrogen acceptors such as oxygen. a primary alcohol + NAD(+) = an aldehyde + H(+) + NADH a secondary alcohol + NAD(+) = a ketone + H(+) + NADH (R,R)-butane-2,3-diol + NAD(+) = (R)-acetoin + H(+) + NADH an aldehyde + H2O + NAD(+) = a carboxylate + 2 H(+) + NADH Binds 1 zinc ion per subunit. Homotetramer. Belongs to the zinc-containing alcohol dehydrogenase family.