Well, it looks like I'm a new passenger in the same Boat with the Rest of you - "How Do Ya Dew ?"Just got mine & it has the SAME problem.  It's probably more subtle than most of you because 1. I play only in my Recording Studio these days at very low volume & 2. I don't use Modulation effects. However, I can tell it's there on the decay of the Note(s), even on Clean. I'm PISSED. No wonder so many Codes are for sale used. If I would have known this ahead of time, I would have never bought it. This is obviously some artifact of imperfected Digital SS Amp technology & don't tell me Marshall never knew about it till us Squawkin' about it. I'm sure they heard it but hoped we wouldn't notice it. When I want Fuzz I'll plug in my Fuzzface, when  want Fizz I'll drop 2 Tabs of Alka Seltzer in a glass of water. This annoying Whine reminds me of my original Zoom H4 Recorder - you have to listen closely to detect these noises, but we all know they are there. Marshall should do the right thing & Recall all of these amps & fix the problem. Give me a SS Amp that gives me a Clean (or Overdriven) Pure Note, all the way through without any BS added to it. Otherwise, this is a FANTASTIC Amp.