Why Preamps Thump on Turn on

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.

I've always read proper turn on sequence is:

1. Preamp along with everything connected to it.

2. Amp.

Shutdown is the opposite

 BUT..... My preamp is connected to my amp with a wire that turns both on at the same time when you do a startup with the preamp remote control.

 Neither the preamp nor the amp instantly come on, there's a few seconds of delay.

 You can here a click in each when they actually power on. I assume this makes the startup procedure okay? Just want to be sure, thanks.

Amplifiers should always be turned on 1st and last off!  This will eliminate speaker thump due to large current inrush filling capacitors in the amplifier.

I follow the instructions provided to me in my Aesthetix Callisto Eclipse line stage preamp. Power it up first and let it warm up for at least ten minutes prior to powering up my CJ LP27M monoblocks. Shut down is the reverse order. With this, I've never heard an in rush thump

Amplifiers should always be turned on 1st and last off! This will eliminate speaker thump due to large current inrush filling capacitors in the amplifier.

The inrush current is the same whether first or last.  However, turning it on first will cause the amp to amplify any thumps caused by upstream components, if any.

The amp may cause the AC voltage to dip momentarily, but that's not a problem for any other components that are already on.