to be fair, i don't think they are all noisey, quite the contrary i think it is an odd one that is.
mine is only noisey every once in a while, and only for a bit, sometimes maybe 10 seconds, sometimes several minutes
usually throwing a load on it will kill the noise.
i figure on takeing it down for 1st world brgs anyway, so i don't see it as an issue really.
it is a st7.5 and will pull 7500watts continous without even getting warm to the touch, well maybe
just over 105 degree's is the highest i have ever measured at that load.
so i personally think it is one hell of a head for the money, i ain't complaining
the whole unit runs so silky smooth that i swear i could set it on 3 coke bottles and run it at full load
and it would sit there happily humping away. very little vibration to the concrete, likely less than 5% of
a concrete mounting system would provide.
i do know that running the unit sitting on the floor can be felt all through the house, vibrate the dishes
and is pretty obnoxious.
now my wife is unaware it is even running in the attached garage while i am flogging the crap out of it doing
dyno runs from hell.
i couldn't be happier, but then again it ain't a lister/oid i am working with either
oh ya lest i forget
LONG LIVE THE MIGHTY CHANGFA
bob g