Just how many outlets do you need for your stereo?

Good point @spatialking. I use three separate 20A circuits (one for each monoblock and one for front end gear) and do maintain some level of filtering on the digital side, using an Isoclean unit.  However, the quote below from the VH Audio site indicates the filtering protects the gear from grunge on the mains, although I suspect the filtering will also protect analog from digital as long as the analog gear is not plugged into the same side of the filter as the digital gear:

For the perfectionist, the IsoClean 60A3 II is fitted with two ultra low impedance Audio Grade 60+60 AMP RF noise filters to attenuate noise and RF associated with city mains. The dual filters of the 60A3 are separate and independent of each other, in order to reduce interactions between your system's components.

@mitch2 The filter should protect equally well in both directions if it was designed to be symmetrical.  But even if it was not, it should give you some filter action.    

ONLY ONE.

A 15 amp standard house outlet will supply about 1800 watts. To be conservative, say 1500 watts.

This will EASILY cover most amplifiers of up to about 300 watts rms/channel, as well as ALL the other paraphernalia like tt, preamp, dac, streamer, CD player, etc, etc.

It is actually best practice to connect ALL your equipment to the SAME outlet to avoid ground loops.

If you use more than one outlet and their grounds are not at EXACTLY at the same potential (even a tenth of a volt difference is enough), you will have a ground loop and you may not be able to get rid of the hum & buzz, unless you use a ground lifter, which may be illegal in your locale.

Stick to ONE outlet.

@cakyol Actually, all of the equipment is plugged into one outlet.   I agree, everything should run from one potential.   A while back I had one amp plugged into an outlet 6 feet away but it was wired to the opposite side of the distribution panel, so the second outlet was out of phase with the first outlet.   I always had a hum problem until I got a breakout panel of 16 outlets that plug into the first outlet.   The resulting annoyance is what started this thread.   I am going to upgrade and I am trying to decide how many outlets my power conditioner should have for future proofing.   It appears that 20 is plenty based on what everyone has posted, assuming wall warts and fat plugs don't cover up adjacent outlets.  

spatialking,

As long as you are on a single outlet, you can have a walwart extender to plug in those wide annoying boxes :-)  Since the plugs are very close to each other in electrical terms, it is unlikely you will have a ground loop problem.

This one has 10 physically widely spaced out ports for almost everything and rated at full 15 amps.  I think you can connect an entire studio to it :-)

https://www.amazon.com/TESSAN-Mountable-Extension-Security-Safeguard/dp/B07VVKSYCZ/ref=sr_1_8?dchild...