 In 1970 , the model M400 was released , which contained 35 notes ( G – F ) and a removable tape frame . It sold over 1 @,@ 800 units . By the early 1970s , hundreds of the instruments were assembled and sold by EMI under exclusive licence . Following a financial and trademark dispute through a U.S. distribution agreement , the Mellotron name was acquired by American @-@ based Sound Sales . Streetly @-@ manufactured instruments after 1976 were sold under the name Novatron . The American Mellotron distributor , Sound Sales , produced their own Mellotron model , the 4 @-@ Track , in the early 1980s . At the same time Streetly Electronics produced a road @-@ cased version of the 400 – the <unk> Novatron . By the mid @-@ 1980s , both Sound Sales and Streetly Electronics suffered severe financial setbacks , losing their market to synthesizers and solid @-@ state electronic samplers , which rendered the Mellotron essentially extinct . The company folded in 1986 , and Les Bradley threw most of the manufacturing equipment into a skip . 
