This is very thematic, so might be of interest only to those doing the puzzle...
1 A. Old band good after drink (10) ?????erin?
13 D. First-timer discarded jack off the top - showed to be wrong (4) D???
NB The thematic elements mean there could be a word missing from the clue, a word superfluous in the clue, an entry that's longer than the answer or an entry that's shorter than the answer.
1a thematic - 4 letter answer G + a usual spirit.
13 thematic - 'first timer' = DEB + 'discarded' minus 'j' leaves an 8 letter answer making a 4 letter entry