Conversation so far:
What was Hardcore 81 by D.O.A. the band?
Hardcore 81 is D.O.A.'s second album
who was fired from the band D.O.A. after Hardcore 81?
Randy Rampage was fired from D.O.A. on January 1, 1982
Who replaced Randy Rampage when he was fired from the band D.O.A.?
ex-Skulls drummer Dimwit on bass replaced Randy Rampage in D.O.A.
who left the bandD.O.A. to work for Black Flag?
After a short tour of California, Chuck Biscuits left D.O.A. and joined Black Flag.
what type of production did the band D.O.A. have?
D.O.A. had hard-rock oriented production, but without watering down the band's political lyrical focus.

Question: how did the band expand their sound?
Self-contained rewrite: how did D.O.A. expand their sound after Hardcore 81?