The only thing that left for you to do is to contact Immedia and report that problem. It might be a problem with cartridge internal wiring.
BTW Rega turntable is a big compromise for Lyra but it shouldn't hum. Lyra can deliver much more from the Basis 1400. Basis 1400/RB300 combo will definitely smoke your current analogue setup.
BTW Rega turntable is a big compromise for Lyra but it shouldn't hum. Lyra can deliver much more from the Basis 1400. Basis 1400/RB300 combo will definitely smoke your current analogue setup.