Emax

Hi all, 

I am dusting my EMAX I rack off for use.

I have just sampled a 1khz Sine wave @ 28khz, with no clipping on the Emax meter, I have played it back through outputs 1 and 2.

Viewing the output in my audio editor, i notice that the wave form has a bump at the beginning.

The audible effect is a sharp attack / pop / clip type of sound.

Is this normal?

Thanks in advanced.