Since about 5 roasts ago, I’ve started hearing a loud whine sound start up towards the end of preheat. Once out of the last 5 roasts it didn’t occur.
It’s not a mechanical, metal on metal sound as far as I can tell, but more like a noisy fan or an inductive load noise. It’s loud enough to hear it all through the machine (the drum is very much like a soundboard!)
Once the sound starts, it can’t be stopped by cycling through the modes. This last time it started before I charged so I cycled through the modes a couple of times, returning to preheat.
It doesn’t seem to affect the roasts, everything continues as expected in all other ways.
I haven’t paid attention to when it stops, will do that next time for sure.
Here is a link to a 30 second mp4 file, the noise starts at 18 seconds.
Thanks for your feedback!