@apogeum Wrote:

One dedicated circuit and all audio components connected with short and low impedance power cables in one power strip for digital/one for analog  to the outlets of a good power conditioner would fulfill most necessary conditions.

See article below, Middle Atlantic Products, Inc.

Power Conditioning
“Power Conditioning” is a very misused term, with no industry standards to allow adequate comparison. Numerous products are
marketed to “cure” AV system noise, lock-ups, reboots and various power quality issues. Many of these are sold partly by fear, partly by
swindling and mostly on misleading “education” that lacks any basis in accepted engineering principles, meaningful data or realistic
demonstrations.
Some people may install power conditioners because they are led to believe that “conditioned power” will improve the way the system
sounds or looks. However, except in rare and extreme situations, these attributes are determined primarily by the quality and
topography of the safety ground system and the integrity of the signal path of interconnected equipment, not by the quality of the AC
utility power.
Two examples of such extreme situations where power conditioning may make a difference include:
- when power is fed from a utility source that is shared by a nearby user of industrial machinery that injects high levels of RF
noise, such as some welding equipment
- when using electronic equipment with cheaply made and poorly designed power supplies, instead of higher quality equipment
that provides adequate noise rejection.
Most power conditioners are essentially low pass filters that are designed to attenuate high frequencies. However, for AV systems,
problematic noise frequencies are under 25 kHz and are essentially unaffected by power conditioners, whose filtering action is typically
effective only at frequencies over about 50 kHz.
The following common problems result in many undesirable situations, including hum, buzz and noise in AV systems, none of which are
solved by power conditioners:

Power Conditioners do not solve
any of these common problems

What actually does solve them

Effects of ground loops (hums, buzzes & video hum bars) Single-point reference ground (can be derived by an isolation transformer), balanced
interfaces, heavy braid shields on unbalanced signal interfaces (keep shorter than 3 ft.),
twisted power conductors
Power line common-mode noise Shielded isolation transformer
AC magnetic field induction (hum & video roll bars) Coaxial cables or twisted conductors within signal and power cables; separation of signal

and power wiring bundles
Cross phase coupling (doubles hums & buzzes) Same phase power
Shield current induced noise Heavy braid shields (instead of signal cables with drain wire)
Pops, clicks and noise from arcing contacts AV equipment powered from dedicated branch circuits, local arc suppression devices at

the appliance or switching device

Control system lock-ups UPS, surge & spike protection, single-point reference ground, avoiding AC electromagnetic

induction into control wires, opto-isolators for long RS-232 links

Hissing at loud volumes during quiet passages Tiered gain structure; higher quality equipment

39 Integrating Electronic Equipment and Power into Rack Enclosures © 2002-2010 Middle Atlantic Products, Inc.

The System Approach to Power Quality

The article form E. Juaneda which I posted earlier really explains the problem of possible ground loops. Anyone who is interested to understand causes and how to fix it will find the answers there.

'The current will take any path that is provided' but like in any voltage divider  more current will flow through the branch with less resistance. If that's the interconnect  it will still cause a problem.

Different potentials always try to equalize to the same potential thus there will be current flowing between the two (or more). It will always use the path of least resistance.

The current will take any path that is provided...

As for using more than one dedicated circuit, to feed audio equipment where signal feeding other equipment is by wire interconnects, in most causes where there is a ground loop hum problem the reason is the wrong type of branch circuit wiring was used and or the method of installing the branch circuit wiring was done incorrectly. Another problem can be the dedicated branch circuits were not fed from circuit breakers connected to the same Line, leg, in the electrical panel.

FWIW, I have two dedicated branch circuits that feed my 2 ch audio system. One for the analog equipment the other for digital. I installed 10/2 with ground NM cable, (Romex is a trade name). Length of the two runs are 75ft each. My system is dead quiet...

The OP’s three 12/2 NM cable dedicated Lines are 35ft each. IF he installed them correctly he shouldn’t have any problems at all.

.

Different potentials always try to equalize  to the same potential thus there will be current flowing between the two (or more). It will  always use the path of least resistance.

Because parasitic current is not only a single frequency like 50/60Hz but a band of frequencies we need to consider not only resistance (DC) but impedance (AC) which makes it even more complex.

The goal of correct grounding is to give different potentials in different audio components a path of least resistance to earth ground so that it wouldn't flow through the interconnect and cause hum or buzz.

Power cables have impedance and that's why it is not a good idea to connect the earth ground of two or more lines in the breaker box. The ground of the  interconnect might be an easier path for the current.

One dedicated circuit and all audio components connected with short and low impedance power cables in one power strip for digital/one for analog  to the outlets of a good power conditioner would fulfill most necessary conditions.

It can have different reasons If one doesn't hear any hum or buzz. Sometimes the potential difference is so small that it isn't audible (you got lucky!). Or the sensitivity of the speakers is too low. But as long as some currents are flowing through the interconnect there is a modulation of the audio signal and depending on the strength it will have some neg. effect on the SQ. If an audio system should theoretically sound better than it does (considering the expenses and efforts) I would always start measuring potentials and consider correct grounding.

I had a classic ground loop problem. I had one dedicated line to my power conditioner. When I would plug my amp into a nearby duplex receptacle  I would get a hum. The circuit my amp was plugged into had a number of outlets on them… I never fiigured out which. Solutions included replacing all the duplex receptacles  on the non-direct line or just adding another direct line. I added another direct line. Problem gone. There was ever so slightly greater resistance in the original installed  line which serviced many recepticals than the direct line… hence a trickle of electricity. A second direct line solved the problem.

@invalid wrote:

I don't know where all these ground loops are coming from with multiple dedicated circuits for your audio system, I have six dedicated lines of which I'm using four currently and do not have any ground loop problems. 

 

I agree!

I have four dedicated lines for audio, one for each monoblock amp, one for analog and one for digital. I do not have any ground loop problems or hum. 😎

Mike

See article below:

Ideally the connection of all the power plugs would be in a star ground configuration (analog and digital gear connected to separate isolated power outlets of the power conditioner) . Power strips  is the next best to star ground.

@apogeum , meaning on one circuit?

An audible ground loop happens when you have two or more paths to ground that are of different potential (voltage).

@cleeds  , what would cause that?

@cakyol , well, as I started this thread by typing, I originally did this 25 years ago before I had a PC and the internet, so I am sure that I probably read something in Stereophile about a dedicated circuit (or maybe more than one) for the gear, and with this, as with everything else in my world, I thought that if one is good more was better.

At the time I had a pair of ARC mono blocks, my pre, three pieces of digital separates, and a powered sub. This has changed, and I now am running a two channel Cary amp, a pre, a Maranzt SA10 as my digital source, and the same powered sub.

In this thread I posted I have read both sides of this coin, and I guess by flipping a couple of breakers to ’off’, I have the option of experimenting & trying it both ways. I pretty much finished up in the attic today, and tomorrow I have a couple of things to change around at the panel, and then I will start testing some stuff out.

I appreciate your interset & I thank you for your input.

Why did you see the need for 3 dedicated circuits ? What is your power requirement ?

This has been addressed above already in a few posts but just to re-iterate:

Connecting different sources to different power outlets MAY cause earth loops and is therefore it is much better to connect ALL your gear to ONE outlet, to reduce the stray resistance between their earth points, which otherwise may cause hum.  So in fact, use of multiple outlets increases the possibility of introducing earth loops.

This article gives a good explanation of the problem why there is ground current:

Because of the way a power transformer is constructed the parasitic capacitors have different values and because the neutral power line is connected to the safety ground, the amount of noise on the two sides of the power line is different.

Ideally the connection of all the power plugs would be in a star ground configuration (analog and digital gear connected to separate isolated power outlets of the power conditioner) . Power strips  is the next best to star ground.

I use horn speakers (105dB sensitivity) which are unforgiving of the tiniest noise problem in the system  but even if you don't hear hum or buzz with  less sensitive speakers the noise will modulate the audio signal  and will produce too much brightness and/or less dynamic sound.

A poor ground, say with 100Ohms of resistance to the outside ground rod, will still have ZERO volts unless a current is applied.

A poor ground point and a perfect ground point with no current will have the exact same voltage: 0 V. 

Connect a piece of gear to each and then have them connect together and there is still no ground loop until one of those pieces of gear causes actual current on the ground to flow.  One of the best ways to do this is often a laptop or PC power supply.  It is for this reason that USB isolators are IMHO something often needed to get the best out of a PC based music system.

An audible ground loop happens when you have two or more paths to ground that are of different potential (voltage). That's what causes the hum. If all your grounds are at the same potential - which isn't difficult to do when using proper dedicated lines - you'll suffer no ground loop issues.

Ground loops only occur if there is actual ground current, even if the grounds themselves are less than ideal, so this is not always a given.

@erik_squires  , could you expound on that for me (as I am somewhat electronically illiterate)?  By that, do you mean if something is causing current to return to the neutral bar via the bare ground wire (the 3rd wire)?  

Ground loops only occur if there is actual ground current, even if the grounds themselves are less than ideal, so this is not always a given.

I don't know where all these ground loops are coming from with multiple dedicated circuits for your audio system, I have six dedicated lines of which I'm using four currently and do not have any ground loop problems.

@apogeum  , thank you for that input. 

I am just about finished up. I did didn't do anything at all yesterday or Sunday, but I am just about ready to get up in the attic and wallow in the insulation and finish that part up.  I want to reroute some stuff at my electrical panel and then I will put the listening room back together

and then I will try it both ways.

What about the ground loops with 3 dedicated power lines to the breaker box?

Even if you have correct grounding in your gear, which is not always the case, you can still get problems  with ground loops if the connection of the ground of each unit is not made as close as possible like using one  power strip for example. Often some digital buzz can only be cancelled by connecting  the power cords of the problematic gear right next to each other in a power strip.

Running 3 long cables to the breaker box where the ground is connected will rather complicate things. Parasitic currents between safety ground and chassis of each unit which normally run through the interconnects and degrade the audio will always  use the shortest path.

I use one dedicated power line with power conditioner (Furman IT20 and PS audio) and power strips and still had to try many different combinations before I could eliminate all noise and ground loops. With my phono section balanced power of the Furman works better, with digital gear the PS audio sounds better.The positive effect on SQ was remarkable.

@ditusa thank you for that. There is a Fastenal store close to where I live that theoretically sells them.

@dodgealum don’t worry about a hijack (which it is not); I have had most of my questions mostly answered. But this type of thread seems to run it’s course fairly quickly & you may not get any more answers on this one. If you scroll down to probably withing the last couple of weeks or so, there are about three more dedicated circuit threads and I remember that they dealt with setting up a new listening room and you may find answers to some of your questions there. I’d post links, but it will be super simple to find them by just scrolling, as they are relatively recent.

And if you don’t find answers there, I think a new thread will yield better results than asking on this thread. (Not that I mind at all if you do, just trying to be helpful.)

Just want to point out that the Eaton 20 Amp and 15 Amp outlets are identical internally. A good thing.

However, only the Commercial/Residential outlets are tamper proof, now required of residential outlets. :)

My experience is the Commercial/Residential are really good, ESPECIALLY when mated to a hospital grade male plug.

Trying to parse from this thread so will pose a question which I hope is sufficiently related so as not to hijack. I am building a dedicated room over the garage from scratch—only drawings at the moment of a new structure. I plan to install a sub panel in the garage fed from the main panel in the basement of the house. The sub panel will only power the audio room and maybe the adjacent office space. I want to install 3 separate 20 amp dedicated lines in the bonus room, each on different walls. One will power 3 outlets between the speakers for amplifiers. One will power a box with 3 duplex outlets for the rest of the components in this system. One will power a box with 2 duplex’s that will power a second system in the room.

I’d welcome comments on wrongheaded thinking AND suggestions to minimize noise, hum, etc. 

@immatthewj wrote:

The duplex receptacle came from Lowes and were therefore nothing special.

I have had good results with the plugs below for audio.

Mike

@jea48 thank you for the added input. A couple of things with a question(s) added:

About my breaker arrangement on my panel:

I typoed again in previous post. There now are FIVE breakers on the leg I used for the 3 circuits I just added.

From the top working down

1) I discovered what the unknown breaker was for. The washing machine. Which I assume is a pretty hefty draw? However, I am relatively confident that the machine is usually not in use when I am listening. So that should be good?

2) In my previous post, I said "TWO of the three original dedicated circuit breakers were on that leg"; in reality, only ONE of those breakers is on that side, and when I finally reach completion up in the attic it will be very rarely in use. So that should be good? If not, I can turn that and the washing machine breaker off when listening.)

3, 4, and 5 are my for the new and truly dedicated lines that I ran directly from my outlets, up the wall, across a section of the attic, and down into the panel.

Besides the sub-questions I raised above, 1) would you say that what I have described make that a pretty good leg? 2) Especially if I turn those other two breakers on the leg to ’off" when listening? 3) And is there any need to do that if those circuits are not being used when listening? 4)And would there now be a need to move my three new breakers down?

(I guess that was more than one question.)

On the outlets: thanks for providing that, and I actually did buy some of that brand at Lowes.. I know because I have a n extra one. The back strap is magnetic. However, I also have them mixed & matched with another brand Lowes sells (I don’t have the box on that one), and it has a magnetic back strap as well. I am pretty sure that they are different brands as there are small differences in their construction. I can easily go to Lowes & finish up this job by buying all one brand.

Anyway, thank you for your helpful input.

@erik_squires   thanks for getting back to me.  Only 4 things will be on these/this circuit(s).  My SA10 SACD player, my pre, my amp and my powered sub.  So going by your above post, nothing really needs to be segregated from anything else?  And I did go to the link you had for surge protection . . . my memory gets shorter every day, but I believe that was the Tripp Lite?

With that typed, I was ASSUMING that a 20A breaker should not only be in front of, at minimum, 12 gauge wire, but also a 20A breaker.

@jea48 thanks for getting back to me. The above was a bit of a typo that I can no longer correct on the post it was posted to, I meant that I was ASSUMING that a 20A breaker should be in front of 12 gauge wireand a 20A outlet.  But I'll leave that alone for now.

The duplex receptacle came from Lowes and were therefore nothing special.

Cover plate is plastic.

I installed the breakers myself and I put them on the leg the window AC and the drier and the kitchen is not on. 

I JUST NOW went to my panel to refresh my memory.  On the leg that I put those THREE DEDICATED LINES on, there are only three other breakers.  Two of them (and this may be confusing) are for TWO OF THE THREE dedicated lines I put in 25 years ago.  I have been up in the attic working with them and they are now going to be three dedicated lines in my living room.  Meaning they will basically not be used for anything or be used infrequently.  So I don't see a problem with them, and, as a matter of fact, when I finally finish up in the attic and hook them up to their three breakers, I can turn them 'off' and they will definitely be out of the picture.  There is one other breaker on that leg, and I just turned it 'off' and did a walk through, and for the life of  me, I canot find anything that isn't working!  And this is a small house!  So I am leaving 'off' as well (unless I accidentally figure out what it powers) , and it should be out of the picture.

I was thinking about putting them at the bottom of that leg, and now I don't know why I didn't.  I think I left myself enough Romex available in the attic that I can move them down and block off those openings in the panel.  But now, after that last paragraph I just inserted, I am thinking that I probably don't need to?

I can check voltage with a MM, anyway.  I am assuming to select AC volts on the MM for that.

I have one more session up in the attic (I keep saying 'just one more) (this is NOT a fun attic to work in) and then some rerouting at the panel itself, and then I can put my listening room back together (the panel actually resides in that room and I am also using that room as a staging area of sorts for all the work I am doing, therefore crap is all over the place in there) and then I can start listening, as you suggest, and try to make some determinations.

Thanks again for getting back to me, you are always most helpful.

Hi OP,

The idea between dirty and clean power has more to do with the power supplies. The extremes are things like LED lights and Ethernet switches.  These tend to have really noisy power supplies which clutter up the AC line.  So even with just 1 power strip I'd try to keep those out of the audio zone. Now a high end SACD player doesn't use these noisy wall warts so I'd prbably be OK with it in the clean zone.

I should also point out that these issues tend to be noticeable after a couple of days.  Try in and out and see which sounds best to you.

But also, I am paranoid about surges so I keep all my audio and video gear on a surge protector.

@immatthewj said:

I was ASSUMING that a 20A breaker should not only be in front of, at minimum, 12 gauge wire, but also a 20A breaker.

That is correct. The breaker determines the ampere rating of the circuit. 20A breaker, 20 amp branch circuit. (#12awg bare minimum wire size.)

.

@erik_squires  I often read to hastily & miss detail.

I was back into your blog and rereading some more, and after clicking on links that took me to Amazon, I note that the PST-8D at MD has a couple of digital outlets (obviously to put a CD/SACD player in a different zone than the clean stuff?) versus the PST-8 at Amazon.

Thanks, @jea48 , as I previously typed: electrical is a weak subject for me.

After that first of about three ’dedicated circuit’ threads, one of the things I THOUGHT I came away with was that a 20A breaker meant a 20A circuit & needed a 20A outlet (along with a minimum of 12-2 in between). I do remember stating that I had THOUGHT that I was legitimate with a 15A breaker protecting 12-2 wired to a 20A outlet (which I thought was even safer, as a 15A breaker should trip even earlier), and it finally being beat into my thick head that the 15A breaker meant a 15A circuit, regardless of what size wire, so the outlet should be 15A as well for legal reasons. With that typed, I was ASSUMING that a 20A breaker should not only be in front of, at minimum, 12 gauge wire, but also a 20A breaker.

Regardless, thank you for clarifying that for me.

@immatthewj

, on page 3 of the instruction manual (pdf) is where it says to connect it to a 15A outlet.

"4. The PST-8 should only be connected to a 120 VAC, 60Hz, 15
amp grounded electrical outlet."

"Connected to a 120V 60Hz 15 amp grounded electrical outlet...

Doesn’t say anything about the ampacity of the circuit. Two or more 15 amp receptacles can be installed on a 20 amp branch circuit. A 15A duplex receptacle is two 15 amp outlets.

The plug on the power cord of the PST-8 is a NEMA 5-15P 15A plug. The NEMA 5-15P plug will plug into a 20 amp outlet.

You meet all the requirements:

120V -------- Yes

60Hz -------- Yes

Grounded -- Yes

15 amp outlet --Yes. (20A outlet will accept a 15A or 20A plug.)

You are good to go.

.

@erik_squires  I have been reading &rereading through your blog, and thank you for providing it, as I am finding it informative.

Forgive me for some of the stupid questions I am probably goingto ask.

I will start with this one

From your blog:

Furman as having the least expensive and most feature packed, which is why as a starter solution I strongly recommend Furman PST-8 with LiFT and SMP as the best. The $180 power strip includes this and is also great add-on to fancier units. While it is a great unit it only has a single zone, so you want to keep noise sources outside of it if you use only one. 

Previous to that is a diagram showing DAC, pre, amp, & TT as being in the "clean zone."  A streamer and Blue Ray are shown in the "dirty zone."  My only source is the Marantz SA10 SACD player.  I don't understand streaming, & really have no wish to, but I understood when I bought it, that if I ever wanted to stream (which I won't) the SA10 is compatible with streaming.  (I guess that refers to the SA10's DAC?)  Does this put the SA10 in the "clean zone"?  Meaning I would only need one PST-8 if I went that way?

Thanks again for the blog.

MD sells the Furman PST-*D Power Station (8 outlets) for $269 + tax which is withing my range, but it says to use only on 15A circuits

Where did you read that?

@jea48  , on page 3 of the instruction manual (pdf) is where it says to connect it to a 15A outlet. 

"4. The PST-8 should only be connected to a 120 VAC, 60Hz, 15
amp grounded electrical outlet."

@immatthewj using them all now.  But not for large plugin items like wall warts 

@immatthewj 

I found out that three dedicated lines was another mistake I made. 

Not really... If the correct type of branch circuit wiring is used, and the correct method of installing the branch circuit wiring is used.

I have two dedicated 20 amp branch circuits that are 75ft each. I used 10/2 NM sheathed cable, (Romex Trade name). Both circuits are fed from breakers on the same Line, leg. I use one for front end digital equipment and the other for analog. My system is dead quiet. Theory for keeping digital equipment fed off a different circuit than analog is  to decouple the power supplies from one another. 

 

MD sells the Furman PST-*D Power Station (8 outlets) for $269 + tax which is withing my range, but it says to use only on 15A circuits

Where did you read that?

This?

• Maximum Current Rating15 (Amps)

That means the maximum FLA of the "power Station" not the branch circuit rating. You can plug it into a 15A (Duplex) or a 20A outlet that is feed from a 20 amp branch circuit.

@jea48  thank you for clarifying the current rating.  For me, electricity is an abstract subject . . . I know how to remove & replace but I don't understand how it works.

On the multiple vs 1 dedicated lines, on the previous thread on the topic, I read that the RFI introduced from multiple dedicated lines for the same system would come from the neutral bar?  I will need to go back & reread that.

My three dedicate lines for my system that I have been referring to are now direct from outlet(s) to panel, on the same leg, they are about 35 (+ or -) feet long, brand new 12-2, 20A outlet and 20 amp breaker. (Which was clarified by, I believe, you and others, on a previous-previous dedicated line thread. 

Those 3 lines are not nearly as well segregated as how you described to me, off line, that yours are.  I can fix that at the panel, but in the attic and in the wall it would/will be some major rework. 

@immatthewj I have an extra Audioquest power cord.  For my use that is fine.  For yours, I personally wouldn't invest too much in a power cord but would use this temporarily until I could get better power conditioning.

I have not noticed any degradation.

I am with Matthew, above, and I wrote about it, below.  Personally I believe that a good power conditioner can be better than dedicated lines:

@erik_squires  , well, the dedicated line is now in existence so I may as well use it, but I do need additional outlets.  The Furman PST-8 is within my budget. . . .

I suppose I was concerned that a budget product might actually degrade the situation. . . .

@immatthewj 

I found out that three dedicated lines was another mistake I made. 

Not really... If the correct type of branch circuit wiring is used, and the correct method of installing the branch circuit wiring is used.

I have two dedicated 20 amp branch circuits that are 75ft each. I used 10/2 NM sheathed cable, (Romex Trade name). Both circuits are fed from breakers on the same Line, leg. I use one for front end digital equipment and the other for analog. My system is dead quiet. Theory for keeping digital equipment fed off a different circuit than analog is  to decouple the power supplies from one another. 

MD sells the Furman PST-*D Power Station (8 outlets) for $269 + tax which is withing my range, but it says to use only on 15A circuits

Where did you read that?

This?

• Maximum Current Rating15 (Amps)

That means the maximum FLA of the "power Station" not the branch circuit rating. You can plug it into a 15A (Duplex) or a 20A outlet that is feed from a 20 amp branch circuit.

@jgoldrick  , for now I can live with only adding more outlets.  Were you able to use all three of the audioquest's outlets?  I take it you noted no perceptible degradation by using it?  And lastly, what are you using for a power cord to connect it to the wall?

I have the Audioquest. It would certainly be a way to add more outlets. It doesn't do anything.  No filtering or protection, but it is a quality product.

I am with Matthew, above, and I wrote about it, below.  Personally I believe that a good power conditioner can be better than dedicated lines: