How long does a tube last?

Vacuum tubes used in our products last between 5000 - 9000 hours depending on where they are used. Signal tubes (the smaller tubes) which are found in our preamps, DACs, CD players and the drive stage of amplifiers generally last up to 9000 hours, and power output tubes (the larger tubes in our amplifiers) about 5000 hours. They do not usually completely fail after this time, but gradually deteriorate as the cathode begins to loose its coating and cannot emit electronics at the maximum rate. The sound usually becomes less focused and 2D like lacking HF response.