It is also important to know what the inputs look like, topology as well as impedance. Some may be truly differential, some may be quasi-differential or balanced impedance but not a truly differential input. A splitter to asymmetric (different topology) inputs can degrade both devices. A transformer might work better but not in all cases; certain inputs require active isolation (active buffer circuit, tube or SS) when run in parallel. Some class D amplifiers have very low input impedance though most have a buffer built into the amplifier.
