You just need to match what is called consumer line level which is nominal 310mv RMS to your power amp sensitivity. Whilst CD players boast 2v figures this does not occur, as all the media you can find will be 310mv RMS, so your power amp needs to be close to this too.
https://en.wikipedia.org/wiki/Line_level
The long and the short you can then use passive attenuation which is represented by resistance, vs adding via active preamps which can't help themselves but add various flavors of reactance, in so doing distancing you from what is possible.
The benefit is you will hear what your source component can actually do,
https://en.wikipedia.org/wiki/Line_level
The long and the short you can then use passive attenuation which is represented by resistance, vs adding via active preamps which can't help themselves but add various flavors of reactance, in so doing distancing you from what is possible.
The benefit is you will hear what your source component can actually do,