This single-IC circuit is pretty basic but is enough to get the TEF6606 audio up to (very loud) headphone levels.

It is just a test circuit, not intended for high quality. There is no volume control, so the volume is on ‘max’ : – ) The op-amp is not bad. The IC was just what was at hand, and with this op-amp with the input disconnected, I hear no hiss through earphones unless I listen extremely closely. However it is poor for being driven from the TEF6606, and in fact it was later found that I could directly connect headphones to the TEF6606, and so this circuit was not needed.