Complex sentence: Its high-quality samples, flexibility and affordability made the LinnDrum popular; it sold far more units than its predecessor (the LM-1) and its successor (the Linn 9000) combined.
Split into simpler sentences: Its high-quality samples, flexibility and affordability made the LinnDrum hugely popular. It sold far more units than it's predecessor (the LM-1) and it's successor (the Linn 9000) combined.