My old good Harman Kadon had given up the ghost. The flash range of Amazon has made me aware of this Sony. I am absolutely thrilled to now, I wonder what I can suddenly rausholen from my old HK boxes. The operation is relatively simple, after some trial and error. The amplifier looks really good. Playing music from the USB stick is easy, I use a 64 GB drive with a lot of music, works perfectly. Also via Bluetooth from the iPhone or iPad goes without problems. Sony has really delivered a great job. I would buy this model safe again.