The listening room was somewhat special, narrow, I tried it in an environment with many iron products and noise sources. The effect is extremely large, the S / N improves, the resolution rises, so that you can clearly hear weak tones and harmonics of the piano that you could not hear so far. Even cheap cables can be wrapped around it to get closer to the finest cables. Especially, it seems that it is effective for ladder type and air core type weak against external noise. In terms of price, if you try to wind a thick power cable, it costs tens of thousands of yen. However, cables with similar performance can not be purchased very much at this price, so we have a good sense. However, side effects are not small, depending on the place you use it will get a metal odor on the sound. Depending on the source, it may be unacceptable to hear it as a kumquin, it seems necessary to carefully select the cable used. However, in that case it is very convenient because it can be easily detached with Velcro.