Compressor causes crackling sound

2.0.3 / Win 7

Play back a fairly quiet score. Classical piano perhaps. Select View > synthesizer > Master effects" and select SC4 compressor in Effect A. Set Threshold to a fairly low value, say -25db or so. Compensate for volume loss by increasing gain if necessary, but make sure the volume does not cause clipping.

As the score continues to play you will hear a crackling sound, not very loud, but there nonetheless.