Though advertised as including stereo power amplifiers, some users have been surprised to find that their audio is coming out mono.  Just to clarify, the power amplifiers in the Powerpods 620 and 740 are indeed stereo - and they work independently of one another - however the mixers themselves are mono.  Therefore, stereo devices connected to the ’stereo’ input channels on these mixers will have their audio summed and sent through as a mono signal.