Neil Kernaghan has posted a review of the Mad Scientist Audio Magic Tubes ($49) at Adventures in High Fidelity Audio. His conclusions:
“Another listening experience to add to the file, of not sure why, but it made a difference. such I feel this tweak is worth a try, with the caveat that your application , system and listening environment might mean what you hear and where ight not reflect mine.”
You can read the full review here.