After years of not being content with my system I let John do the full upgrade of my KW550. Being curious after John I picked it up when it was ready, which was quite a trip living near Amsterdam. But meeting John made it all worth wile. What a nice and knowledgeable guy he is! But after installing the amp back in the system there was a definitive improvement, but still something annoying me. To the point that I sent the amp back to John for a checkup…. Shame on me!! The amp appeared to perform flawlessly in John’s system. John politely suggested my beloved, and I thought perfect, pair Dynaudio Confidence C4 might be the cause of the annoying highs and lack of imaging. I must admit it took some time to accept this as a possibility. I then had Ben van Leliveld, owner of Acoustic Matters, take an acoustical blueprint of my system and listening area. Ben does this for high end systems but also for (famous) recording studios and for demonstrating rooms for high end dealers. Apart from very accurately determining the acoustical problems of the room, Ben immediately found the Dynaudios to measure anything but flat. These were newly bought speakers! John was right all the time: the Danes were to blame. The acoustical problems were solved relatively affordably, and anyone should treat oneself to do this because it is by far the most effective way of finally hearing what a system is really capable of! Then after selling my Dynaudios I went on a search guided by Ben van Leliveld. I visited some dealers to listen to speaker systems and almost broke my back on the process because Ben strongly advised I do all the listening with my own KW550. Now comes the fun part: although the speaker dealers knew (or knew of) the KW550 they looked a bit as if they considered it oay but nothing special and certainly not good enough for them. But all and I repeat all of them became very silent after the KW550 started playing and warmed up a bit. They listened without comment and afterwards said thing like: ‘you should never sell that amp’ , this doesn’t sound like a KW550 at all’ or ‘you have to pay at least 20.000 euros to get something as clean and powerful as this’ So I am now listening to a pair of Harbeth 40 in an acoustically treated room and the difference is unreal. Finally I understand what a profound and unexpected change John did to the KW-550. There is a wide deep stable stereo image. No harshnes. Everything is tonaly correct. Instruments and voices sound so natural. Finally there is MUSIC and I am enjoying it. The job John did to the KW550 is amazing! Thank you, John!