Hi guys, thanks to a friend named Craig Johnson now I know why the original Watterott TMCs are whining. It’s because they run in SpreadCycle mode and we all have been running in StealthChop mode with the chinese drivers with black PCB. No matter if the jumper on my board is soldered or not they run in StealthChop mode. They have little mini jumpers on the back that are being left open. This leaves CFG1 and CFG2 floating and the driver is runnig silent. Now this is not automatically a bad thing, you don’t have to do anything if you don’t have problems with layer shifting. I’ve been running mine since I created the first prototype board and never had problems with the VREF set to 1V. So if you’re using the chinese clone MKS drivers, you don’t have to do anything. If you’re using the original Watterrott TMCs just desolder the jumper on my board and they will be running StealthChop, too without any whining/hissing. Of course you can run in SpreadCycle mode (noisier), but then you need to solder CFG1 and CFG2 jumpers on the back of the chinese clone drivers. If you have any questions feel free to contact me.