Interesting, that would explain why I had to pad the test tone in the DAW first, and it lines up with Avantronica’s experience using the CV output from the A4, too. I can switch the inputs between -10 and +4 reference but not the outputs so it wasn’t really an option for me.
This might explain why some people find it really easy to clip the OT’s inputs and others don’t have trouble with it. I generally assume that any gear aimed at professional users is going to be +4 but it actually makes sense for the OT to run at -10 because it will be used for a wide variety of sources and it’s always better to attenuate a source that’s too hot than to boost a source that’s not hot enough.
According to the manual, my Casio CZ-101 has a maximum output of 1.2v RMS, which according to that calculator would be 1.8dBV - well under the 5.8 dBV (1.95v) that the OT’s inputs are rated for, but I can easily drive the OT’s into audible digital clipping with it in the project I’ve been using lately. I’ll have to double check and see if I’m clipping the inputs or if my gainstaging in the OT can be tweaked to keep it from happening.