From inSync reader Flawn W. comes the following:
"In your notes about operating levels last week (inSync TTOTD 6/20/97), you said it was generally safe to assume that RCA and 1/4" jacks would be -10, while XLRs would be +4.
An unfortunate exception to this common practice is the RCA jacks on the otherwise-magnificent Mackie 1202 and other Mackie mixers. Their RCA jacks for tape input and output run at +4 dBu unbalanced! I haven’t checked to see if they corrected this in the VLZ series, but I’ve run into some overload problems driving other RCA gear from the Mackie’s tape out jacks."
Flawn, thanks for your comments. The situation is that Mackie’s equipment tends to be over-engineered when compared with lots of other gear; their outputs are capable of driving a good +22 dB in some situations – enough to overload connected gear with limited headroom. In looking at the diagrams for the MS1202, it appears that the nominal output on the RCA’s should be around -10. If you are driving them even moderately hard, they can certainly exceed this nominal figure.