Hello, I have a Marantz 1090 amplifier http://www.classic-audio.com/marantz/1090.html I want to play vinyl records on a turntable through amplifier and into a lap top and use software to capture and "clean" the sound. Which connections on the back of the amplifier do I use to connect the amp to laptop?
You need to connect amplifier's Tape Out to Computer's Line In socket.
I've used the free program Audacity to transcribe vinyl to a computer and thence to CD or MP3.
There are more advanced pieces of software with sampled filtering (i.e. you sample the crackle and rumble and it eliminates anything on the recording of that order). However the usual wisdom is to save to digital as is and only clean up a copy --keeping an original in case "cleanup" software improves in future.
Some software claims to automatically solve the problem of separating songs in an album sequence so that you can save each as separate files (necessary for creating a searchable CD or for MP3). You can do the same manually with most programs in a variety of ways and this is probably more reliable than doing it automatically (where quiet bits may be mistaken for the end of a song).
Incidentally, your amp is the bigger brother to the 1050 I found dumped in the garbage last year, cosmetically good and still working perfectly after about 30 years. A bit bright sounding for my tastes but plenty of power ! They really don't build them like that any more.