Edited by Ryushi - 1/16/13 at 9:47pm
At that price, most likely not. But then again at that price why not? Since I am assuming you are new to amplifier building, even if it is a bad sounding amp, you will definetly learn from building it. It will help you out in making less mistakes on a better kit.
Single "OP amp" based design using the LM4881. I would imagine the sonic qualities of that chip will be the predominant factor in how well it performs. It looks like its a component designed to drive low impedance loads, with its limited voltage swing and the fact that TI specs it as being unity-low gain stable.
The LM317 is a voltage regulator. Feed it with a Vin and its output will maintain a steady Vout to feed the 4881. I think it converts extra voltage to heat, when Vin is greater than some pre-determined amount. So presumably increasing Vin will only increase heat, decrease circuit efficiency as a result.
Not sure if theres any filtering capacitance going on, but that part of the design could also significantly affect the overall performance. Its questionable if the LM4881 even "needs" it. If TI designed this chip for use in portable devices, one would think they designed it to be able to handle unwanted DC.
I have no first hand experience though with either the circuit or components used... so please let others chime in and correct me on any of these points.