Hi Nic,
No - not tried it; but one doesn't really have to. The (by Philip's own admission) very cheap TDA1543 dac is only capable of about 12-13it accuracy at very best, and the NOS approach will not improve that - quite the opposite in fact, regardless of input signal bandwidth claims. If you need a similie: it's not unlike a battered old pub upright piano, with a blanket or two thrown over it in to quell the innate squawk. OTOH if it is cheap enough, by all means have a play. As Lord Kelvin observed, 'in all matters things ultimately come to the ear for judgement as the organ of hearing.'
I could illustrate by way of meaningless graphs, & will save that for next time you are within reach of a nice beer or two. Kind regards.. M