Help with playing analogue through computer, pls...

[huntsman]

I have a pre-amp from Digitech which I last used six years ago to play LPs and cassettes through my computer.

I tried again a few days ago, and...nada! I have taken cables from the output of turntable and cassette deck to input of preamp, and then gone from Preamp's output to input of computer's soundcard.

In the past, all I had to do was start the record or cassette and I would hear the audio from my computer speakers. No matter what I try now, all is silent...

I've tested the T/T and cassette deck by going directly to an actual amp, and they work just fine.

Am I missing something obvious, here?