Bought a new (to me)tube regulated Power supply

[swingarm]

I bought a lambda 71 regulated tube power supply. it arrived too today. I have seen one before a few years back and there was a buzz when it was operating. Mine has no buzz but seems to be ok voltage wise and does not drift or anything. Seems weird that there is no buzz coming from the unit. Does anyone here own one? Any insight would be appreciated. I know this is not an amplifier question, so forgive me if I have posted in the wrong place.

[PRR]

Most bench gear does not buzz, not so you hear it.

(House-size transformers inherently buzz strongly from magnetostriction, but nothing you are likely to own. Acoustic buzz even as loud as a fruit-fly is something loose.)

[swingarm]

I removed this post as the content link is behind a patreon member paywall and was not meant to be public it seems.