MOTM

I once owned the MS-10 , MS-20, & MS-50.
the MS series as a whole ,.....or at least
the 20 & 50 I had, -were very distict in that
"shortwave radio" kind of way - although this
may also have been the analog delays I use adding to 
that nifty "shortwave" quality. I notice that
on the MOTM-420s' the sine out on self oscillation
sounds more square-like than the original MS stuff
which You may or may not want , maybe I'm doing
something wrong ? any ideas - anybody?
Thank You for reading my semi-feckless mianderings.
Bill