Mosfet mist?


Greetings,

I have read several articles on the sonics of mosfet amps to include Adcom,B&K,Counterpoint,Perreaux,etc. What exactly is mosfet mist and how would one know what to listen for. Are some amps more prone to this mist than others? I have a Perreaux 1150B doing woofer duty on a pair of Focal 706s spkrs(A modified Parasound 1000A on top)How would say the 1150B compare with a B&K in relation. Thanks.
south43
It's actually quite easy to detect. You'll need a fluorescent lamp, a variac and a pair of wrap around 3-D glasses. Let your amp warm up for 1 hour while driven to output 1/3 its rated power. Place the lamp approximately 1 meter above and pointed at either the amp's or the speaker's binding posts. Turn off all other light sources in the room. Set the variac to the standard voltage in your area and turn on the lamp. Raise the variac's output voltage exactly one half semi-tone above your area's normal voltage. Now the hard part -- rapidly fluctuate the variac's output voltage over a quarter semi-tone range, this is known as "voltage fluttering". With your 3-D glasses you should now be able to see a slightly purplelish mist being emitted from the binding posts. DO NOT BREATHE THIS MIST FOR EXTENDED PERIODS OF TIME! Stop fluttering, turn the variac back to your standard voltage, turn off the lamp, but keep on the 3-D glasses. Remain in the darkened room for 10 minutes.

Seriously, notice the alliteration - Moseft mist. It's a nonsense phrase invented during the cocaine crazed 70s by a writer trying to be clever. It's supposedly a kind of softening and homogenization of the sound. If you think you understand what the last sentence means, then maybe you'll hear it too. Otherwise, it's not something to be taken seriously.
I thought Sam Tellig (Stereophile) came up with it and has since said that improved mosfets no longer display it, or something like that.
I have tried this, but it's hard to be precise with the +/- Variac sweep with the 3D glasses on as it is hard to see, plus I am mostly in the dark here. I thought I detected some smoke/mist coming from the Variac, but nothing from the speaker terminals. Also I have blown a couple fuses in my amp. Are you sure this is the way to do it?
My friend is currently running a B&K Pro 10 preamp, B&K 2020 amp I think, Marantz cd player.... powering MMG Maggies. I hear no such mist. Sounds detailed and clear to my ears. Seriously, I've heard much worse in systems costing 3 or 4 times as much.