none with double crowns. I compiled a list of units that are known to ship with these oddities and none can be had for less than a few grand. My strategy is to find ungraded chips that test well, or ungraded chips with the same batch numbers as those that S2 chips came from. The latter strategy is playing out well for me, as I don't have the equipment to pursue the former. Also, I have around 50 TDA1543/TDA1543A and have been just randomly plugging them in and listening and there are some that sound better than others. Remember, these chips were never graded at all.