You are correct LukeFF. The S-class boats were too small to have a TDC installed. One key sentence from the article says:
"The new TDC, which went into the fleet boats, where there was room to shoehorn it into the conning tower, was designed for use with the 21-inch Mark-14 torpedo."
Here is the link to FleetSubmarines website for the entire article...
http://www.fleetsubmarine.com/torpedoes.html
So we can expect to do it the old fashioned way in the S-boat (using the Mark-10 torpedo that only had contact exploders) and to have the TDC (with the defective early torpedoes) in a Fleet boat.