Thank you, but I don't see the point of warming the tubes if you have to go through "off" to get to "on"... Strange design, or is it just me?

Hello, I'm new on the forum so thanks in advance for your understanding and help... I just bought a Slash signature SL-5 and I am a little confused with the power-on switch (Up: standby / Center: Off / Down: On). What is the correct sequence to turn on and off the amp??? If the standby switch would ...