My response is for those who like me saw the ads and curious as to whether or not this is worth trying out. Also kudos to Robert Harley who called it as he heard it knowing there was going to be some controversy to put it milidly.His article convinced me to give it a try.I installed the Qol between my preamp& amps.The first thing I noticed was the increase in volume which makes comparisons problematic because the louder volume source will tend to sound better. The second thing I noticed switching the bypass on or off and adjusting the volume was there were some changes in the sound and soundfield but nothing at that point that would get me to spend my money. After a couple hours, I decided that since it was a new unit, I would give it some time to break in. I shut down my amps & ran music through it for 2 days 24/7 before I sat down for another listening session. Again working with the volume differences, I went back & forth with the bypass switch.Things were getting interesting.The soundstage, width ,depth & height had noticeably increased. The music had an additional richness to it. There was more air around the instruments and overall the sound was simply more natural.Simply miked acoustic music that is well recorded has a live truthfulness to it. I ran it another 24 hours after this session and had friends over. My buddy is a skeptical electric engineer. His wife loves music but thinks we are a little crazy. After 5 minutes she said ," you don't need to tell me when it it is on or off, I can tell instantly. The soundstage is bigger and everything sounds better". My friend the double E took his time but by end of the evening he encouraged me to buy it. I spent a couple more good listening sesions before making up my mind to purchase one.To me it gets me that much closer to the live event. With some recordings you might not notice much of a differenc and with others you will have a smile on your face. I never heard anything I never noticed on a recording before but the presentation was different in a positve way. Background vocals that previously buried in the mix were delightfully involving. The same went for drums and cymbals that sounded much closer to real then before.If you are considering trying a Qol, I encourage you to do so with one caveat and that is if either your speakers, amp or preamp cost less then the Qol I would wait a while because there are a lot of good changes you make make to a system for $4K. For the record my system is not in the $250K I saw in another response but I could buy a new top of the line Corvette with the money I spent on it.