Just how many outlets do you need for your stereo?

@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.    

I just found this device on Amazon, it has 8 outlets and can be interconnected for more outlets.  It is cheap enough, only $125.  I am not expecting much in the filtering section, as they don't even spec the number of surge joules it can handle or the bandwidth of the filters.   But, what I do like about this is the fact it sequences the outlets on, which I do need.   I recently blew a midrange driver when I accidentally flipped the control electronics power switch off before the power amps.   That was a $3000 repair, with freight and insurance.   Then, it morphed to $6000 when I discovered the manufacturer upgraded the speakers and the original drivers were no longer available, so both heavy speakers had to be shipped cross country.   Granted, it was a pretty significant sound improvement, so I didn't feel so bad when I got them back.  I ordered two of these units for 16 controlled outlets, I will check them out, and report back here on how well it works.  https://smile.amazon.com/Outlet-Power-Sequencer-Conditioner-Controller/dp/B07P76C2PF/ref=sr_1_6?crid...

You are right, I did word it in a most ambiguous fashion.   My bad. 

My real intent was to find out the number of outlets that other folks are using and try to figure out what I would need in the future for more expansion.   My APC has 16 outlets but I can only use about 10 of them since they are so close together.   Plus, one of them has a wall wart power supply so that covers up two more outlets.  I am sure if I had a full 16 I would be good with that.  

The other part of the question is separating digital and analog.   Most conditioners have separate digital and analog outlets since the filtering is usually more aggressive on digital components than analog. 

Power outlets usually have different filtering as well, although I would find it hard to believe I would need more than 6 power outlets, assuming I had monoblocks on everything.  

@vegasears  Thanks for that, I had to chuckle: yep, I hear you.   If your are going to do it, why not overkill it and never but never have to do it again!  Gotta love that philosophy!

@mitch2 The only reason for having separate digital and analog receptacles is whether or not the receptacles are independently filtered.   Analog gear doesn't usually pollute the lines with noise but is rather susceptible to it while digital gear usually pollutes it quite well.   If the receptacles are independently filtered, then noise from digital gear won't get into the analog stuff.   If you have no filters, then you are right, it doesn't much matter.   Note that some analog gear now uses switch mode power supplies, so they have their own pollution issues to deal with and from a noise standpoint, are not exactly pure analog.

Also, in researching this a bit further, I noticed that the Pangea Audio line of AC receptacles do not have isolated grounds while the PS Audio receptacle is an isolated grounded unit.   A point to consider when buying one of these upscale receptacles.

@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.  

@mitch2 @audioguy85  Thanks for the info, it was very helpful. 

The two units from Amazon arrive today - these are the two I mentioned before .  For $250, I am not expecting much in the filtering but the sequencing will be much appreciated.  I will report back on the innards and performance.  Hopefully it will serve as a stop gap for now until I find something suitable for long term use.

The two Pyle PS1000 units arrived today.   The PS stands for Power Sequencer and it will sequence 8 outlets  Overall, it is a clean build and well worth the $125 price for each.   The sequencer can be daisy chained so up to 100 outlets can be sequenced, although each unit requires a connection to the AC mains.   See it  here - https://smile.amazon.com/Outlet-Power-Sequencer-Conditioner-Controller/dp/B07P76C2PF/ref=sr_1_6?crid...

The sequencer, voltmeter, temperature gauge, and relays are all controlled by a microprocessor.  Looking at the manual, I see a 24 dBm / octave filter on each outlet.  The filter is made up of two X caps and two common chokes so there are two 12 dBm / octave filters back to back on each outlet, making up the 24 dBm filter.  No values are specified, so I can't sim it in Cadence.

That is the good news.  They somewhat bad news is they also have the typical Y capacitors from line and neutral to ground,  Although the Y caps can improve noise filtering somewhat, it also bleeds some line current onto the grounds, so it may induce a low level hum into the system.   In general, I dislike inducing any current onto Earth ground, but it is a very common practice.  [UL codes are pretty disgusting in this respect, as they allow multiple milliamps of bleed current.]   The primary difference between regular line filters, like this one, and hospital grade line filters, are the lack of Y caps in medical grade filters.
I'll do some more involved listening tests this weekend and next weekend, if I get some time in the lab, I will see how much of that microprocessor clock bleeds onto the outlets and what the filter bandwidths are like.   Hopefully, it is better than the APC unit I have now.

@jafreeman  I agree, when you have a ton of money invested in a system, why skimp on dedicated 20A line? In general, it isn't too expensive to have an electrician install one and usually it's free to get a quote.

@clearthinker Those torridal transformers really do have a hefty turn on surge.  We have some big ones at work which will blow a 30 A, 240 VAC breaker every single time the units are powered on if they didn't have a soft start circuit.  That plus the higher cost of a torridal over a E Frame is the main reason they are not used for audio as often as they should.   For power amps, they are just the perfect transformer.   The reduced EMI footprint and better line noise immunity is also a big plus for both power amps and small signal devices. 

So, I installed the Pyle PS-1000 unit and have been playing around with it for a while now.   The very low level hum that was evident from APC unit is gone and with it there was a noticeable sound quality improvement.   I'm not saying this Pyle unit is the end all of all EMI filters, but clearly it is noticeably better than the APC unit it replaced, which was significantly more money in a major way, too.   I do believe this is a great, low cost, stop-gap fix while I experiment with higher end line filters.

I did notice that since the equipment is completely powered off now, it has a warm up time of about 15 minutes.   The equipment is well broken in, only the Pyle unit is relatively new. 

As for the number of outlets, it has 8 switched and one unswitched.  For the home theater I need 11 switched outlets, so I piggybacked one outlet with this unit:  https://www.homedepot.com/p/Yellow-Jacket-2-ft-12-3-SJTW-Multi-Outlet-3-Outdoor-Heavy-Duty-Contractor-Adapter-Extension-Cord-with-Power-Light-Block-64824501/303020524  

I ordered another unit so I won't need to piggy back anything.