I have two identical headphone amp boards based on the LME49600 reference design. One board uses LME49720 for feedback/servo and the other uses LME49990 for feedback and OP27 for servo. Other than that they are identical boards and components.
The board with LME49990/OP27 has a high DC offset of around 1V when it's powered up, but after a few seconds it settles to ~1mV. The board with the LME49720 doesn't do this.
Any clues as to what might be causing this?
The board with LME49990/OP27 has a high DC offset of around 1V when it's powered up, but after a few seconds it settles to ~1mV. The board with the LME49720 doesn't do this.
Any clues as to what might be causing this?