All mentions I've made to brickwalling on the DR2d refer to signal sent to the mic-input and line-input jacks. Brickwalling refers to the analog input stage overloading before the ADC does. Since the metering is done at the ADC, the meters and clip light on the recorder will not indicate that overload. That means a hot signal can overload the input and cause distortion, even though the level shown on the meters and clipping light indicator indicate what would appear to be good levels- if the signal level is increased further, distortion will increase, but the meter peak level will not. The average level indicated on the meter will increase however, and you may notice the meters behaving differently by 'bouncing' or moving less than would be expected. That behavior is a good hint that brickwalling may be occurring, but isn't obvious.
It is possible to use settings below a line input setting of ~93 or a mic input (low gain) setting of ~60 without overload, but only if your set it so that your recorded level peaks lower than full scale. The lower you set the input gain (to accommodate a hotter signal), the lower the point at which overload will occur below full scale- the point at which you won't be able to tell when the brickwall distortion begins by looking at the meters or clip lights. There is no benefit at all from using a lower input level and trying to avoid that 'invisible' overload point. You'll only use less of the effective dynamic range which the recorder is capable of, it will still overload at the same point, and the meters will lie to you.
The short version is this- If the meters are peaking with an mic-input level of ~64 or a line-input level of ~95, then turning it down on the recorder won't help, even though it looks like it does from simply looking at he meters. Instead you'll need to reduce the signal level before it reaches the recorder inputs.
