I've been reading up on the optimized psu and only one question remains. Is there a particular reason that the 330nF capacitor is exactly 330nF? As I understand the purpose of the 2200uF cap is to remove large ripple and the 330nF cap filters noise. The reason I'm asking is that I have a bunch of caps at home but no extra 330nF since that isn't as usual as the series "1, 2.2, 4.7, 10, 22, 47...". I figure that one could use another small value cap for noise filtering with the same result (220nf or 470nF). Am I wrong? (Ordering a 330nF wouldn't really be a problem. It's more that I'm genuinely interested in the design.)