Recording Speed

For this to be cause and effect something unanticipated or unstated would have to have happened.

Changes to the Control Board, Firmware, Machine Settings, stepper motor drivers, or mechanical components are wholly responsible for speed control.

Changing the engrave head may change output wiring or increase power draw but this would (at its worst) show up as lost motion and under-powered steps that failed to create movement.

It may appear that it was speed that changed. More precisely, it would be the distance for the same unit of time. If you are observing a symptom of under-powered stepper motors the engraving (recording) would be undersized and misshapen.

If you repeat the job with the laser unplugged from the control board and the engraver speeds up, you may have a weak power supply or a wiring concern. If disconnecting the output wiring from the controller has no effect on the motion then the laser isn’t the current cause and a look at the Machine Settings would be the next step.