I finally tried this product (received a bottle as a gift a few days ago - thanks Bruce). I started out by cleaning the tube sockets (output only as the signal ones were too small for the pipe cleaners supplied with the kit)) and all of the tube pins. I fired up the system and heard an improvment in HF definition. Following this I went through all of the connections over the next day (including the A/C ones - even the wall outlet) and it sounded even better. I had thouroughly cleaned all of these connections (or so I thought) less than four weeks before, with electrician's alcohol, but the Kontak raised quite a bit of grime (mainly from the tube sockets and also from the inside area of the RCA's). The hi-grade alcohol that I used before always made a difference/improvement, but not like this stuff. Great product.