Mellotronists

didn't I read somewhere long ago that Dave Biro used two M400s to make 
the tapes for Birotrons? Crossfading between the same notes played on 
two machines?
  The tone quality of those things was always hard to distinguish in a 
mix....TORMATO and CRIMINAL RECORD have it buried in the background 
except the bit at the end of Don't Kill The Whale.Pretty nasaly,thin 
sounding.Wonder what the tone circuitry of those things was.
  I heard a story that Chris Squire once replaced a few of Rick's 
Birotron 8 track tapes with some cartridges of Mexican music before a 
rehearsal and when Rick reached up to play a part he really had a rude 
surprise.                                     Charles