Of the ampsandsound amps the Pendant has the lowest apparent noise floor, IIRC, to the point that Zach told me he would take it back if it had any that bothered me.
The next quietest is the Mogwai SE which has been revised over time to be even quieter. I have a very low tolerance for noise, so outside of the Pendant, I was hesitant about ampsandsound amps when I was looking for a tube amp. A lot of people really enjoy them though.