Why Preamps Thump on Turn on


I posted a fun discussion on my blog to get into the details of this turn-on phenomenon. 

 

 

erik_squires

Showing 1 response by elliottbnewcombjr

Carvin Audio Explanation. Substitute Preamp for Mixer.

"THE RIGHT ORDER TO TURN THINGS ON

Before anything else, let’s review the power up sequence for a common live sound scenario. Power up in this order:

  1. Sound sources like keyboards and synths that are connected to the mixer
  2. Mixer
  3. Power amps
  4. Powered speakers and stage monitors

 

  1. PROPER POWER DOWN SEQUENCE

    As you might imagine, spikes occur when you turn equipment off as well. Since all the gear is on before you start powering down, you’ll need to power off in the opposite direction (first in last out). So in the example above, active speakers and power amps would be turned off first (so they don’t receive a spike from the mixer), then the mixer…and finally the onstage gear connected to the mixer."

Some power controllers have sequenced power banks that do this for you.