Amp and preamp on same outlet?

How much/many dynamics will be lost in the same outlet?
How much/many of thom will be gained via dedicated linez?
Will there be anything more lost or found in the same outlet?

Move to a more efficient amp like Class D and no problem ever. I have both my 500w/ch monoblocks on the same outlet and dynamics match teh best I hear anywhere and are teh best I have ever had myself.

Efficiency done well is always a good thing.

My circuit breaker used to go frequently with modestly high power power sucking Class a/b amps.

Now the only time it might go is if I power up both 500w/ch Class D monoblocks at the same time. They never show any signs of strain or break a sweat running. Plus I can leave them on most of the time and teh impact to my power bill is negligible as quality power amps tend to go, so overall cost of ownership is lower as well.

If you have modern, reasonably decent gauge copper electrical wiring and a quality outlet, invest in a great noise reducing PC and conditioner. I use Transparent and MIT PC's and Transparent power conditioning with great success.

I agree with Ebm, +1

A well regarded equipment manufacturer told me having everything on the same line is optimum. I suspect this is related to the ground loop considerations Al posted.

This has nothing to do with ground loops which are an entirely separate matter (FWIW, if your equipment is properly designed, ground loops should never be a problem).

The concern with different lines is that one might be on one side of the incoming AC power into the house, the other might be on the other. Sometimes you can have leakage problems caused by the two lines being of slightly different phase (or a lot different phase if taken off of a 3-phase circuit). Sometimes this can result in hum. If the equipment is properly designed though this should be a minor concern.

IOW two different lines off of the same side of the incoming AC line (which is 240 Volts in the US and then gets split into 2 halves each 120Volts...) eliminates that concern. If your equipment is prone to ground loops that can still happen though...