recording to Reel to Reel from McIntosh 5300 integrated amp

I looked at your Mac, playback is no problem.

Recording NO. You wound have to hook the source via cables to your RtR. I suppose you could rig up a switch box.. Not the best idea..

Most of the Mac Preamps are made for tape/phono record/playback..

Tape is one of the things Mac has always supported.

I guess you'll remove the other thread.. You can..

Best of luck

Oh for the days of old when everything had a tape monitor loop, phono stage.... You can use pre-out but probably better to do like the man said and connect source direct to deck, then use either headphones to monitor or connect the tape deck to the pre and monitor on the system.

Thank you both for your input. Perhaps one follow up? 

The music source would be hi definition streaming (like Tidal). I can currently play through a phone to the USB port of the Mcintosh to the speakers. 

That's why I wondered about the PREOUT from the amp... otherwise I don't know how I would get the streamed music to the tape deck. 

Is there a particular product/additional equipment that I could purchase that would allow me to accomplish my objective better? 

By the way, I realize this project may sound illogical. But the hope-for tapes are a gift for my brother in relation to the equipment itself, which he recently acquired through no will of his own and there are no tapes (and there is very little 2-track music for sale regardless). I wanted to at least create a tape to depo the tape deck and watch it work, so he can appreciate it... hence trying to record a tape off of streaming.     

For streamed music buy a streamer. SQ through the phone is NOT worth recording.
Donworryboudit.
However it would still sound better than high speed duped pre records which are discontinued.