After speaking with another Joule customer that shares this same problem, he shared with me a technique for substantially lowering the noise floor:
1. Once the amps have warmed up, with no music playing, put your ear up to the speaker. Now, reach down and press the DC offset button (or any of the output tube bias buttons). Has a significant part of the noise/hum stopped? When you release the button does the noise return? If so, move on to step #2. If you hear no difference than this tweak is not for you.
2. Insert a toothpick between the button and the edge of the hole in which the button sticks through, with the button depressed, so it can be held down.
3. DO NOT, I repeat, DO NOT forget that you cannot have two buttons simultaneously pressed on one of the monoblocks. Jud Barber makes this very clear in the manual. Only put the toothpicks in when you're just about to sit down for critical listening. Take them out when not doing so. When the toothpicks are in, you cannot accurately adjust voltage, and you definately cannot bias any of the tubes.
Checking the DC offset does not have any effect on what you are hearing musically, other than dramatically reducing the noise/hum of the amp that ensues during basic operation. From what I understand, the communication between the display and the point in which you press the button are not in the musical signal path.
With that said, I have talked to Jud, and he has told me that he has shipped numerous versions of the Mark V iteration of the VZN-100, and he has not heard the kind of deep concerns that myself and this other customer have expressed. Maybe this noise/hum issue is relegated to mine and the other customer's OTLs only. Maybe we're just the ones that are most sensitive to it, and nobody else seems to be concerned. Either way, the "toothpick tweak" is an aural lifesaver for me. It may put the user at a disadvantage when trying to interface with bias checks, voltage checks, etc; but sonically, this, in my opinion, is the only way that I can listen to the amps now.
-Jake