I mixed for 3 years on an Allan and Heath as well as several other analog consoles and was used to running my channel gain at 0db with the transient peaks never reaching above +6 (this is unity gain right?). The meter measured from -64(ish) to 0db and then up to +12(ish) or so. Now that I am in a new location I have been running digital consoles that places 0db at the very top of the meter (clipping). The only part of the console that shows clipping at +12(ish) the way I am used to is the meter for the bus faders.
By observation I have found that at around -15db on the scale that clips at 0db will produce a 0db (10 or so under clipping) on the bus meters it sends to if both faders are set to unity. Now we are replacing the console with one that no longer has the metering scale I am used to.
Why do digital consoles now clip at 0db instead of +12 or so like I am used to with every analog console I have seen? And what is the proper gain level to use on these new digital consoles to have unity gain?