SR - 18  and  16  are all you need  in a drummer  machine ,  if  you  skeptic  about  brand  check  thier  release video on  item  from  1990s , the  guy  that made  it sounds  like he should  work  for  nasa , the  brilliance  of  both  items are way worth  the  price  ,  great  to have  item  that  exceeds  its  value ,  i  use  it  with  looper pedal  ......  thats  all  i have to  say ....... mic  drop