Quote Originally Posted by bfalls
Tweaks have always been speculative, "Green Stop Light" the green marker you use to stop spurious laser light from escaping into the player from the edges of a CD, comes to mind. Shakti Stones are another. Both tested by high-end reviewers and found to "make a difference".
It sounds like you just need some assistance understanding the mechanisms involved. Ever tried looking at a laser pointer through a CD? What do you see? Red light! I can't speak for green pens, but I can speak for the Marigo mat. It is flat black on one side and dark green on the other. What happens when you do the same experiment adding the mat? Wanna guess? It eliminates light scatter.

It is common knowledge that all transformers generate EMF fields around them. It is also common knowledge that toroidal transformers have replaced laminated transformers in most applications because they generate far less local EMF. Have you noticed that trend? Did you ever wonder why? Shakti Stones, like the VPI Magic Brick before them, absorb the EMF field. When placed atop a transformer, they reduce that field which can effect the sound quality of nearby circuitry. That was demonstrated to me over twenty years ago. Unfortunately, toroidal transformers are not available for large high voltage tube amplifiers. Which is why I use DIY bricks atop the power transformers on my amps.

rw