Hi, This is an article Dave Belles has printed on his website, I hope it helps. The Cost of Leaving that Amplifier On all the Time by David Belles I would like to take this opportunity to welcome you to our audio Web site. In this section, we would like to offer some of our thoughts on subjects that, we hope, will be of interest and help. Our first topic concerns a question that I am asked many times. What about leaving my power amplifier on all the time? The logic behind leaving an amplifier on all the time is that it is supposed to sound better if the amplifier is never turned off. There is some truth to this notion (components that are already warmed up tend to sound better), but there is a down side that must also be considered. First, the reliability of the amplifier could be compromised if it is left on all the time. The components most affected are the active components (i.e. diodes, tubes, and transistors). A transistor can be affected in two ways: first, the current gain hfe begins to deteriorate. Second, the transistor develops current leakage due to heat dissipation, leading to unit failure. Passive components (i.e. electrolytic capacitors, power resistors, and circuit board material located near heat sources) can also be affected over time. Electrolytic capacitors experience a drying out of their electrolytes, causing capacitance loss and leakage. This leads to gradual degradation of the bass and eventual component failure. Other considerations include the greater likelihood of damage to the amplifier from household hazards, such as, thunderstorms, line spikes, household spills, children, and pets. When making the decision whether to leave the amplifier on, or turn it off, one must consider the benefits and the costs. I recommend turning the amplifier off when it is not in use, and turning it on about ½ hour before listening. To my mind this represents a good compromise between amplifier wear and tear, and the best listening experience.
