Don't know what you mean by "slide ruler" but it may be that your signal is too hot and thus clipping.

The RECORD fader is a different one from the PLAYBACK fader, you must find the Recording fader for the What U Hear input and adjust that one.

Use the VU meters inside PT to confirm, the LH meters are for the RECORD or INPUT side of things, the RH is for the Playback or Output.


--Mac