Update on Master Fuse, after 250+ hours of settling I can really tell what it is doing. It is a little more detailed than the M1, much more expansive in terms of sound stage, and slightly more 3D and colorful. That trickiness of this fuse is that it adds a significant amount of treble response (though not harsh at all) and in an amp you end with a sort of "V" or "U" shaped response with emphasized treble and sub bass, but the midrange and mid-bass a bit scooped out. It makes sense that this pairs with the SR Purple which seem the opposite to me, tons of midrange and mid-bass.
It also makes sense that these fuses would be meant for sources given their tonal profile. Most people will want a thicker sound from their amps, and for those who find the Purple to be too thick, a Master Fuse upstream may balance it out.
I’m going to try and see if replacing the other fuse in my HM1 with a Purple will result in more tonal balance. That will determine if the combo will be a replacement for the M1 pair, or just an interesting alternate.
There is one area that the SR fuses are really ahead of the Audio Magic ones, adding an SR fuse is like adding a subwoofer, the amount of punchy and raw sub bass. Despite the treble focus the Master still has amazing sub bass.
