Just checking to be sure that  36 π (pi) should be  36 Ω  (omega) on page 29 of the 740 Extra Features Manual. 

If that's so, then:
--the manual needs correcting:  Change pi to omega, or write out "Ohms."
--and I need assurance that the 740's audio output impedance really is 36 Ohms. (36 Ohms seems an unusual impedance for an audio output circuit.)