@pharmacylaw - specifically, how did you connect your Marantz Receiver (used as a passive tuner) to your McIntosh (amp)? If connected incorrectly, component damage may result.
An amplifier expects a small signal to amplify, so it’s very bad to connect it to another amplifier. Both Marantz and Mac have amplifiers, but the Marantz has a bypass connection (preamp out) that bypasses/skips the built in amplifier. Also, it’s best/safer to minimize both volumes before powering up

