FYSETC TMC2209 Stepper Motor Driver In stock

I converted my printer to an extruder with a larger diameter extruder gear and immediately had problems with missed steps and a chattering stepper motor. Replaced my 4988 with one of these. Easy enough to install, no resistor required inline to the Tx/Rx, it's on board. Extended pins, added a copper sink on the chip, tweak Marlin here and there. Dead silent, tons of torque. I couldn't print at 50% speed before, just ripped one out at 150% (like 90mm/s) not even at full 80% RMS. Printing right now at 900mA, but still dropping it more. At 1500mA the copper sink I installed on the bottom was at ~40C, but with my fan it's at room temp at 900mA. Now I need 3 more, just for the silent printing alone.