Ketchup, In response to your question, which I think was aimed at Dover, I wrote after Dover's post that I visited the NVS website and did not find the word "servo" mentioned there, which still leaves open in my mind the possibility that they don't use a servo. They may have said they use a "laboratory grade" power supply, however. If I just missed seeing the mention of a servo on the NVS website, I do not mind being corrected.
I have a laboratory here, albeit a biological one. In my lab we have many power supplies that are used primarily for electrophoresis. We don't generally use Lambda brand, but I have seen them in other labs. The voltage regulation required for a lab grade power supply used for electrophoresis is probably not as stringent as that needed in audio amplifiers and preamplifiers, or in the best AC motor controllers. I have always meant to bring in one of my meters and determine how much AC is present for a given set DC voltage put out by one of our lab units, but I have never done so. However, in other kinds of laboratories, especially where physics and chemistry are the subjects, I could imagine that voltage regulation is far more stringent. So, the term "laboratory grade", by itself, is fairly meaningless.