I wouldn't plug digital equipment ( or anything with a digital "readout") into the preamp as it can "dirty" the power going into the preamp with RFI. In fact, it's best to keep digital equipment on a different wall circuit altogether.
A turntable, cassette deck, or an older analog FM tuner should be OK. Or an accessory that only gets intermittant use, such as a record cleaning machine. No wall warts either. You don't want unshielded transformers that close to your preamp circuits.
A turntable, cassette deck, or an older analog FM tuner should be OK. Or an accessory that only gets intermittant use, such as a record cleaning machine. No wall warts either. You don't want unshielded transformers that close to your preamp circuits.