For those of us building amps, RCA and Banana jacks for input/output are always needed.when the cost of jacks from PE approach cost of class D amp, it is silly. You may want to check out this place for jacks at low cost. Here is an example of 10 pairs of RCA's for $3.70 shipping included.
Cheap AV 2-Female Jack RCA Socket Connectors (10-Piece Pack)
They have class D amps too.
Cheap AV 2-Female Jack RCA Socket Connectors (10-Piece Pack)
They have class D amps too.