I don't know the specifics of your Carver, but yes, in general you can connect line-level sources such as audio from a CD/DVD, cassette, tuner, etc., to inputs designated for VCR, tape, etc. There may be some small differences in input impedance for different input jacks, but this would be a problem only for rather unusual cases. Your phono preamp (presumably a phono pre-preamp) will also have a line-level output, so that can be connected as well.