Are you using a mini headphone stereo plug that splits into RCA’S right and left channel?
If if you are proposing going straight to the auxiliary or tuner RCA input from the iPad, I would say that this is a bad idea. I mean, the sound quality from this as your source is going to be poor. That is if you are relying on the tiny DAC inside your iPad.
Maybe I misunderstood how you intend to take digital files on your iPad and play them on your MC-2205, are you using a DAC?
I listen through my Bryston DAC to digital files from my old iPhone 4 through a Wadia 171i digital dock that outputs it’s (really clean) digital signal via a digital coaxial cable into the Bryston DAC. The DAC has XLR left and right channel outputs to my Bryston BP-26 preamp. The sound quality is better than my Sony XA-5400ES CD player in some respects - lots of detail and texture and layering is preserved and replicated even on slightly lower res recordings.
You cannot expect quality digital sound sound from an iPad outputting stereo analog out where you rely on the tiny iPad DAC. The sound quality will be harsh, tinny, inaccurate, etc...
I’m surprised no one asked about your DAC yet. Maybe there is a digital dock that accepts he iPad’s Lightening connector (instead of the headphone out) in a bit perfect way that can be imported into the DAC of your choice.