S3L insert L/R clipping

Hi



I use TC electronic system 6000, MD4 limiter, as digital hardware insert on master L/R.

L/R direct out is routed to Protools input 63/64, pre fader, recording the mastered mix.



Only if I drop the Limiter output -2dB, recordings are OK, with normal setting like (-0.3dB), I get peaks on the PT meter and recorded audio.



No problem with using a plugin Limiter.



Same setup works fine with our Profile desk.



Is this a known problem?



Thanks for any ideas.



Patrick