Acoustic Revive RIQ-5010 5010W

Sixmoons Reviews the RIQ-5010 - "..Smoky quartz will give you slightly more bass effects in articulation and extension. The clear quartz will give more transparency to high frequencies and will make the soundstage wider. Turning the quartz disk facing upwards or downwards has a bigger sound difference because quartz has a directional effect. It takes some effort but try and find the sweet spot direction of the insulator. If four insulators are facing the right direction, it will give a better phase characteristic to the sound. RIQ-5010 and RIQ-5010W are used underneath or on top of equipment."...

...The effects across the different amplification devices were consistent: The clear quartz disks created a more open, detailed and transparent presentation from the midrange on up. I noticed little change below. The smoky quartz disks' effect from the midrange on down was to give a more spacious presentation, with the size of the soundspace increasing and better beat emphasis in the bass. From the midrange on up, the smoky quartz disks smoothed out sibilance and provided a more natural and less electronic overall feel...

...The bottom line is that the effect of placing a quartz disk on a power transformer ranged from subtle to rather dramatic. The primary effect was that the music became more musical and less electronic..." - Jeff Day, Sixmoons.com