Cry out for the old record format (4)
'cry out' is the definition.
'the old record format' is the wordplay.
'the old' becomes 'ye'.
'record format' becomes 'lp' (abbreviation for long play record).
'for' is the link.
(Other definitions for yelp that I've seen before include "Shrill short cry of dog", "old boast", "bark sharply", "(Eg, dog's) short cry of alarm", "Cry of pain".)