[LAU] Alesis ADAT out to S/PDIF ?

[Ivan K]

I have an old Alesis QSR which has an optical digital output
that is in a "proprietary Alesis format".  The manual says:
 
  > The digital connector follows a proprietary Alesis format
  > that carries all four audio outputs of the QSR (Main and
  > Aux, Left and Right) on a single fiber optic cable.
  > Either pair of outputs can be converted into standard AES/EBU
  > or S/PDIF stereo digital audio format by using the Alesis AI-1
  > interface. 
 
So, short of buying a used Alesis AI-1 (for maybe $100) is there
anyway I can convert the output of the Alesis to something
that can be read by an Spdif input?
 
Thanks;