SIXTYNINER
Well-known member
...hmmm , put power voltages on the input of the audio cards ?It looks to me like you want to check the transformer secondary as you put the power supply under load, so an oscilloscope which you can implement as software (free) 8 Best Free Oscilloscope Software For Windows to check the transformer waveform, as you put the supply onder load, either by connecting it to the device you want to power or to an electronic load (expensive) might work.