Can anyone help? I used to be quite good at this, but brain now fuddled.

I want to wire my tuneramp and PC together so I can use the PC like a
cassette recorder.

So I want to be able to use the tuner-amp to replay from vinyl (via
phono input), or stand-alone cd player (via aux input) or from tuner, or
from PC.

And I want the PC to be able to record from whichever source is selected
on the tuner-amp.

The PC has a limited sound card with just input and microphone and
ouput, and also has a tv tuner card, and that feeds the input jack on
the sound card, so I'd have to put a doubler on the input.

I feel I should be able to stick the PC in just like it was a cassette
recorder and use the record and playback phono pairs on the back, but it
never seems to work so well, and produces noisy and inferior sound.
Sound from PC is better if I use the tuneramp aux input for the output
from the PC.

Also I can't find a way to wire it up so the tape monitor select button
will give me either the source (say the tuner) or the some signal coming
back from the PC ..

I realise the relative sensitivities must be all over the place, but
what am I missing? And how should I balance it?

I don't want ultimate hi-fi at the end ... but decent sound from a range
of sources while I work at the PC ... and maybe dump down to MP3.

Thanks.