Phrunt, you mentioned potential EMI issues multiple times and I am wondering how you are doing your noise cancel? Are you doing the quick 1-2 second press and taking what channel it gives you, or are you doing the "long hold" noise cancel where you keep holding the noise cancel button and the machine cycles through every channel, slowly weeding out the less effective channels until it eventually narrows down to one or two channels, and then finally comes to rest on one specific channel? Tom D has stated that this is a critical factor to getting the best out of the Manticore. The manual mentions it, but almost in passing and really doesnt stress it at all. Tom makes a very pointed issue out of it! Perhaps this will help? Also, are you finding any differences with or without ground balancing? So many factors and "tweaks" to dialing in a new machine to attain maximum performance!