Yes I am unhappy with my S-300i. I am not sure what happened but while playing vinyl I heard some weird sound. I raised the tonearm to free any hair or dirt causing mistracking. I realized the noise continued. I changed sources and it continued. The woofer on the left speaker was really dancing and I had no idea it had such extension and I quickly shut off the rear power switch. It settled down as the power drained from the amp.

Of course the amp is out of warranty but it has a history of problems. The first one I bought had a surface mounted switch that only worked with the remote control. Music Direct exchanged amps without a question. Nest was noise that continued in the right channel after being placed in standby. Krell was concerned and had me ship the amp and they repaired it. Then I blew it up using the wrong speaker cables and Krell was kind enough to fix it under warranty even though it was my mistake. Now the left channel is a little funky and thought it was going to harm my speakers.

Of course now I am using the Onkyo A-9555 int. amp that is older but more dependable. I will call Krell tomorrow but I am not willing to put much money into it since I have issues with it's dependability. I enjoy the sound but for 5x the price I paid for the Onkyo I expect some reliability.