I took my 722 out for its first stealth gig tonight (just got back - I'm writing this while I transfer). I recorded almost 3 hours at 24/96. I learned a few things in the process and came up with some other ideas to try.
Setup:
I used gaffer's tape to cover the meters, input lights, and power light. I wanted to use the -3 dB indicators on the left to approximate levels. After I open up the files and look at them, I'll let you know how well this technique worked for me. This brought to mind one change I'd like to propose to Sound Devices: in stealth mode, have the backlight always off and use the light button to toggle the LEDs on/off. That way, I can still check levels without too much difficulty, and turn everything off otherwise. If I'm stealthing, I don't think I'll ever need the backlight to read the LCD.
I put it vertically in my waistband to get it in, then once in my seat, took it out and ran it standing up (battery side in my lap) with my jacket over it in my lap. I should mention that I had to bring the battery in separately (pocket, in this case) because with it attached, it's a bit bulky.
Use:
A nice, perhaps undocumented, feature of this device is that some settings are retained when the power is off. Phantom is one of these things. I set up the unit at home with my mics, and powered down with phantom still on. All I had to do to get running is have the mics plugged in and turn the unit on. Bit/samplerate settings are also stored while off. Once the unit was on, all I had to do was hit record. I just did that when the venue filled up, but in retrospect, I could have used the 5-second pre-roll and started with plenty of time using that method. Ahh, next time.
Once I had the record light on and saw the counter moving, I locked all of the front panel buttons. Then, after a song, I adjusted levels. The 722 needs more gain to get similar levels than I'm used to with the ULN-2. For example, if I know a certain perceived loudness level would usually get me to -3 dBFS at +20 gain, the 722 needed at least 10 dB more. I am guessing that's a function of the input impedence and how it matches with my mics. It's entirely possible that people could see the opposite effect, but odds are not with the DPA 402x series.
And now, a warning: In enclosed spaces, this fucker gets HOT! We're talking uncomfortably hot to the point where minor burns could occur if you're not careful. About two hours into the show, I noticed that my shirt was warm where the unit was resting against it. I put my hand on the outside of the box and had to pull it away, it was so hot. I held the 722 by the corners and moved it out near my knees, allowing more room for the air to circulate around it. When it cooled down enough to touch it for more than a second, I used my hands as heatsinks. By the time the show ended, it was back to just warm, borderline hot. I would strongly recommend a pack for stealthing this thing.
I'm guessing the heat issue does NOT occur if you're only recording to CF. Whenever 8 GB cards become cheap enough, I think I'll grab one of those and use it for stealthing. All of the heat came from the right side of the unit, which is where I'm guessing the HD is.