Using FPGA 6115 and DAC version 1.1.7 when doing the bit perfect test. I am using the Bridge. The DS screen displays a green tick and says Bit Perfect , then , underneath BitPerfectTest 24 96. All good IMHO. However, when the test is running there is a strange noise coming out of my speakers. The best I can describe the noise is an EE-OR like an emergency vehicle siren only not very load. I tried 1.1.9 with no change. I did this when I first became aware of the BP test. I didn’t hear it then.