my polisix is VERY VERY warm at the back / centre of the unit …putting my hand there is not really pleasant… yes, that hot! …
your thoughts?
edit: should have made clear is it NOT the sound that is very warm 
…the actual unit…
PSU/Transformer.
This is talked about in the KiwiSix upgrade: http://kiwitechnics.com/kiwisix.htm
Looks like this transformer is a cooler replacement: http://www.altronics.com.au/p/m5118-powertran-18-18-80va-toroidal-transformer/
thanks Adam ( new avatar?, i like it! ) … just bought the polysix 4 hours ago… carried it around, plus public transport… now this … sigh
yea dude… my peaceful protest.
Sorry to hear about the (possible?) dud.
Maybe ask the previous owner about the behavior, how long it had been doing that, or do some research to find out what is an acceptable level of heat. The KiwiTechnics guy is very knowledgable.