If I may jump in (David Janszen, here), no one has had a failure with the [former] amplification, at least not yet. This year, however, we've changed to an all Hypex system. It comprises the dual 500W nCore NC50MP and the Hypex digital and analog input cards in each cabinet. We expect this will be just as reliable, and it offers more inputs, more power, and higher sample rates and resolution, among other advantages. In both cases, the amplification is modular and easily replaced, and the warranty is 5 years.
That said, there have been a few electrostatic panel failures in both passive and active versions over the years caused by a problem with one of our former employees' technique. We dealt with these quickly and without charge, and hopefully, someone will chime in and verify that.