I use Hifi Tuning Supreme fuse for both my DMC-30SS-2 and DMA-260 and yield noticeable improvement, especially for the Pre. The mid range is richer and sound is livelier. I am a technical guy myself and I don't understand why a fuse can improve the sound, but the fact is that I can hear it. In fact I can even differentiate the sound caused by the direction of the fuse (Yes! This sounded crazy). I found this when I was using the Hifi Tuning SilverStar fuse on my YBA CDP/Pre/Power. I checked the hot end of the IEC socket and installed all the fuse with the same orientation, based on the logo on the fuse, but it yielded different results. Eventually I just installed them based on what I heard (one orientation give a more lively and more forward sound which I preferred). Besides me, my friend could also differentiate the sound of different fuse direction. I found this really strange and I tried double blind test and I am still able to differentiate without fail. I guess that are somethings still cannot be explained with today science.