Ludlum is rare among equipment manufacturers in that they design with user-servicability in mind. They happily took phone calls and emails from my 16-year-old self about how to diagnose and repair various instruments of theirs I had picked up on eBay, many of which were long obsolete. Their schematics are still open, to my knowledge.

I have no relation to the company, just a very satisfied customer.

Very interesting modification. Perhaps it can be an optional accessory.

The Ludlum mode 3 is an amazingly steady instrument and looks like it can last forever. I only hope its user interface can be improved a little bit. It is not obvious how to turn it off because there are two Off labels. One is for sound and the other is for power. Panel around the sound switch looks like:

    ON
  switch
    OFF
    AUD
  button
   RESET

Because AUD can be read as belongs to the reset button below, people turn off the sound and think they have switched off the meter :). The ON/OFF sound switch can be labeled as Unmute/Mute.