I might not have things plugged in correctly, but I feel the 3.5mm TRS to 270 degree 5 DIN plugging in at 29 on the attached image could be the best bet. I enjoy the idea of using my receiver for volume, tone control, etc.in this particular situation; recording/streaming the actual performance of the receiver and source (the "präsenz" presence amplification on this receiver is wonderful). The receiver doesn't have a monitor output. On the image below 9 is the "monitor socket", 7/8 are "tape/cassette sockets".
The manual states for the monitor socket "
Monitor: A tape recorder with the record monitor feature connected to socket (9(monitor)) via stereo cable RVK 2 (which was a 5 din to 5 din) enables the quality of the program being recorded to be continuously monitored during the recording sequence. If the "Monitor" button (38) is not pressed (LED not lit), then the current program is reproduced directly. When the button (38) is pressed, however, the program just recorded may be heard with a slight delay as a continuous check on the sound quality.
Do not forget however, to reset the monitor function by pressing the "monitor" button (38) again (LED not lit), otherwise all other types of program (radio, records etc.) will not be reproduced. The "Monitor" socket (9) is suitable for connecting table units with a high level ("Line" output)."
Now like I said prior, I have a 3.5mm TRS to 180 degree 5 DIN which can connect my PC to the monitor socket. I've tried every combination of the monitor button, but my PC still receives no viable audio signal. Tried connecting to the Stereo Mix as well.

Now the other option is to connect through inputs 7/8. The manual states for the tape/cassette sockets: "
Tape recorder/cassette recorder: Two stereo tape or cassette recorders may be connected via sockets (8) and (7) for either record or replay, and also transcribing from one tape to the other. The sockets are identical and conform to DIN 45500. Please use 5 pole connector cables (e.g. SABA RVK 2). This means that any program passing through the 9241 (with the exception of signals fed in via the "Monitor" socket), may be recorded and replayed in stereo with HiFi quality. The recordings are not influenced by the volume and tone settings of the 9241. For
replay, press the corresponding button (41) or (42). The LEDS of the display (23) indicate the type of operation in progress. With two tape/cassette recorders connected the following combinations are possible.
Button (41) "band 1" pressed:
-replay from tape unit 1
-record on tape unit 2.
Button (42) "band 2" pressed:
-replay from tape unit 2
-record on tape unit 1"
I tried every combination of this and still my PC receives no audio signal from the 3.5mm line in.
So with this information, how would you all proceed? I am relatively uninformed on this sort of thing.