It looks like the limiter may have been on. What do the suspect channels sound like if played in solo? If they sound reasonably OK-not distorted-then the limiter was likely on. If they sound distorted, then the signal is likely clipped. Tinybox mid-gain is +18 dB, which should be fine if in fact the LINE was selected for the input.
When I use my tinybox I almost always use mid gain and never have clipping problems, but I set the input to LINE IN and low gain, as my dr-680 dr-70 both have HI/LOW gain settings.