Bring legendary Marshall tone to your rig with the JCM900 4100
  guitar amplifier head. With dual channels, a shared 4-band EQ,
  and 100 watts of all-tube power, you've got an amp that is ready
  for any gig on any stage. This version of the Marshall JCM900
  includes a series effects loop with true bypass operation —
  perfect for gigging musicians with lots of pedals. Step up to the
  professional's choice for outrageous Marshall tone — the JCM900
  4100 guitar amplifier head.