Acts almost equally well on phenylacetaldehyde, 4-hydroxyphenylacetaldehyde and 3,4-dihydroxyphenylacetaldehyde. 2-phenylacetaldehyde + H2O + NAD(+) = 2-phenylacetate + 2 H(+) + NADH Amino-acid degradation; L-phenylalanine degradation; phenylacetate from L-phenylalanine: step 3/3. Homodimer. Can also use NADP, but prefers NAD. Belongs to the aldehyde dehydrogenase family.