I was only at Steve's for a few hours, so I didn't get a chance to mess with any settings on his Fisa. Besides, I wouldn't want to. With my luck, I would probably inadvertently save the settings to the Fisa memory and then Steve would be confused as to what was happening to his new Fisa.
However, when I tried to compare my 8X with the Fisa using the L/Mono Jack on the both the 8X & Fisa, I could not get anywhere near the volume output from the Fisa compared to my 8X. In series with the Fisa & my 8X was my Bose T4S mixer that has tons of Gain. I could increase the gain when using the Fisa and could get some volume out, but only with a lot of "hiss". The signal/noise ratio was not good. Maybe the Fisa output card was bad.
your observations and conclusions are valid
for over half a century, line outputs have been pretty
much standardized across the board in the electronics
industry.. literally ALL musical instruments have the common
L/R/Mono-Stereo output scheme and all of them MUST be
within a whisker of each other in terms of output power
otherwise an entire industry of wireless audio gear or line
inputs on powered speakers or chromatic tuners or
recording devices and everything else would be made untenable
so you checking in an A/B test through a typical professionally used
PA system the Korg vs a similar Roland was a very legit test, and no
amount of excuses can explain your results away
something was definitely wrong
i hope you get a chance when your buddy gets it back to repeat
the A/B comparison, and i hope you can narrow it down.. it is
very ,much worth looking into.. Your experience as a gigging Pro
and the level of gear you are known to typically use makes you the
perfect person to make these kinds of comparisons, for real life usage,
and then to report and figure out what the problem is.. if it will be
something significant that a warning flag needs to go up, or if it
is just something odd, a one off problem, that this specific Fisa
suffers from and how to take care of getting it up to "normal" again
your observation doesn't need explained away.. it needs pursued
to a conclusion.. so thanks for noticing and hope you get a chance
to run it down sometime