When I received this I was initially disappointed. The sound was perfectly clear and (I hate to use this word!) neutral - but "flat & boring! However, after approx. 2-weeks of pretty constant daily use the sound has "opened-up" dramatically. It still takes a good 30-mins after switch on even from standby to open-up which is mildly frustrating, but now I understand why people love the Hypex amps. It is very clean, open and dynamic - with no compression, no harshness and no edginess. My KEF LS50s have never sounded so good! I think mine is still improving, but now I am sorely tempted to upgrade already to the higher specification Hypex mono-blocks! A minor comment / observation; the delivery packaging was "nothing special" - being more like "Amazon packaging" than a high-end manufacturer - which is probably reasonable / fair and I would prefer the money was spent on the hardware anyway.