Hi.

Another question: What modification to the temp/voltage control circuit is needed to make the output voltage lower (i.e. let the fan turn slower)?
The empeg is has a specified operating temp range that goes up to 55°C, so I would like to have a steeper curve on the voltage that starts later, which would probably mean I need a different thermistor. But even with the thermistor you used, it should be possible to have the fan stay off/inaudible up to at least 30°C or something.
Like in my stereo(home)setup, I know for sure the ambient temperature of the room will never exceed 26°C, but the empeg might get some heat from below, so that it goes up to 50°C while operating (well, after operating for more than an hour), so I would like the fan to still be silent at that temperature, because even a slow fan should be able to cool the empeg down quite a bit under these conditions. Others might have pretty high ambient temperatures, and thus need more airflow. a small poti to adjust the fan speed would be nice.

cu,
sven