Gentlemen: Please can we get back to comments on the subject of the forum rather than arguments about one’s personal preferences, my preference may not be the same as yours. I have been involved with audio for more than 60 years and have designed and used both linear and digital equipment for better than 50 years. Of course, all linear devices change with temperature both positive and negative from their off state that is a fact, this also true of most passive devices, but to lesser extent. This is why a designer of said equipment accounts for those changes in their design, or should. If one perceives an improvement after a component warms up, so what. March it seems every where you start posting it becomes an argument which I find strange for a manufacturer of equipment that sell to the people you are arguing with. NTC (thermistor) for those who want to know, a resistor with a negative temperature coefficient so that resistance decreases with increasing temperature, there are also PTC thermistors that are the opposite. By the way if your power supply has one keep your hands off as they can get quite hot. As to turn on surge it is more an issue here in the U.S. with 110 to 120 VAC than it is in the U.K. or Australia with 230VAC half the voltage double the current, unless they have repealed OHM’S since I went to school. If you want to see problems with tun on-surge hook up a current and voltage scope probe to the various point in a power supply and down stream to the other components. Now having said that a proper designed supply takes this into account with the components that are designed in or they should. I power down my equipment except the mentioned tube pre amp that keeps the filaments active hence the turn/off via remote or front switch on my PURIFI build, but I still find it improves after around 30 minuets of warm up, at least this is MY perception. You mentioned a blind test of significant differences due to warm up, how do you keep the equipment from warming if it is on? Then you said HYpex performance degrades as the components warm up, so this must mean the components are changing in some temperature dependent way. All I am trying to get at is if you as an owner of a piece of equipment and perceive or prefer your equipment to be left on so be it, you are the one responsible for energy cost or the repair bill as a result. In the case of class D amps, I don’t think 14 watt is going to make much difference. If that is the case maybe we should all wear insulated clothing as we enjoy our audio equipment. As we as average human beings heat up our soundings at 330 to 350 BTU / hour or the equivalent to 100watt light bulb, that is unless we are at room temperature for a long extended time, in which case we are not listening to anything. Please let’s get back to enjoying our forum.
JimM