Personally, I won't touch any audio gear that gives so few technical specs as that does. It does not touch on the amp itself in the specs at all other than 4 watts, but what impedance is that at? I still have no idea if I need to recommend a circuit to bring the voltage of this thing down because I need to either know the rail voltage of the unit and/or at least the rated impedance for that 4 watts (and VERY preferably the distortion level at that (better: and more) output levels). And for the horns you're powering, what impedance are those? How much power are you looking to drive them with?