unpluggin entire system

Typical advice is to go backwards in the chain for powering off.

Amps then pre then...and so on.

I don't think it makes a bit of difference when powering down, but I'd personally turn OFF each piece of equipment first, then unplug everything. From past experience, most of my equipment failures have all taken place when turning ON equipment. 

I can report that sometimes it DOES make a difference. I have at least one piece that blows its fuse  if not powered down first.

Word.

As fuzztone reports, some amps have a slow start function.  It limits current flow into the large power storage devices (caps and inductors) to keep from blowing fuses.  If you have one of these type amps, then your manual will tell you so.  I have an amp with huge capacitors (taller than the transformers) and it has no slow start feature.  

So I just turn off my PP10 when I go on vacation and turn it back on when I return. If your component has a simple on off switch with no associated circuitry, then it makes no difference. 

The second question would be whether your power plant likes to start up under load.  my load is only 200 watts so I am not concerned. 

Jerry

Maybe it's just been routine for me, and I should have been a little bit more specific. For me personally, when powering down, in this order:

1) power amps 2) preamp 3) any other audio gear after that 4) finally power conditioners. Power amp first, so that speaker damage doesn't take place by powering down any other piece of equipment first, by sending some type of pop or snap through the power amp(s).

When powering up, the same, but in reverse order.

@fuzztone Hmmm, interesting scenario. What piece of equipment might that be, and why do you think it's doing that? If it's a power amp, no explanation needed.