It's not clear that you actually have a problem – if so, let well alone. A few red lights are OK – what does it sound like ?
Otherwise, I'm guessing you are probably over-driving the chain. The H9 expects a guitar level input – some effects loops give a hot line level, which is too high.
That said, there are a few things you can do.
1) If you are overdriving the first input, there is not much we can do (the H9 does not have an input attenuator). You could find a tech to make up a pad with a few 1c resistors.
2) But, it sound like the first unit might be OK, and it is that later ones that are peaking. In which case, turn down the main output levels. (latest revision required). Or, if the problem only occurs on certain presets, adjust their preset output gain.
