Music with differences between class A and class D amplifiers

Hello,

I own an ATI AT523NC Class D amplifier and recently purchased a Schiit Aegir Class A amplifier to compare two different approaches to amplification. I've been switching them back and forth all day but can't hear any difference at all between the two in my music. The good news is, both of them sound great.

Does anyone have any suggestions for music that sounded clearly different between their Class A and Class D amplifiers? If so, I would appreciate some pointers on what to listen for.

My setup is PC (Roon) -> Matrix Audio X-Sabre Pro DAC -> Schiit Freya Plus Pre-Amp -> Amplifier -> KEF LS50s.

Thank you for your help.