Basically, the source component should have a low output impedance and the amp should have a high input impedance (100K ohm or >). The source also needs to have a high enough output voltage to drive the amp (input sensitivity).
You should try running direct to the amp if the impedance matching and voltage can be satisfied, it does offer a nice transparent presentation. But, you may also find that the overall dynamics and "flesh" are missing.
Also, keep the IC short and of low capacitance.
I just did a quick browse of the SA8260 manual and don't see any mention of a volume control, only for the headphones.
You should try running direct to the amp if the impedance matching and voltage can be satisfied, it does offer a nice transparent presentation. But, you may also find that the overall dynamics and "flesh" are missing.
Also, keep the IC short and of low capacitance.
I just did a quick browse of the SA8260 manual and don't see any mention of a volume control, only for the headphones.