# Advice on Power line Noise and Recommendation on Power Conditioners



## lag0a

Hi.
   
  I am wondering if there is an expert out there that knows about power line noise whether it is from RFI or EMI or recently I've just heard about impedance mismatch or whatever the hell else can be introduced into power line noise that could interfere with your headphone setup as in a computer as a source -> DAC -> AMP -> headphone. 
   
  I've heard about balanced transformers, power regenerators, double line ups, and power conditioners so which is the real cure for power line noise without contraining and restricting dynamics which I have experienced before in a monster cable power line conditioner. I have also tried an Equitech balanced transformer and it I loved how it gave a natural flow to the music and it drops the noise floor so I can hear details better, and for some reason a good power cable makes the Equitech sound better in my headphone setup, but it is really expensive.
   
  I am wondering if there is a cheap alternative approach to cleaning power line noise with respect to clearing up sounds in your source introduced from power line noise. Why do power line conditioners differ so much in price point when they all do different things to clean up sound? Are there cheaper alternatives with a better and right approach since technology is changing but are we left with only the same methods for cleaning up power line noise?


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## WarriorAnt

not exactly what your'e asking about but I thought you might be interested.  
   
  http://ep2000.com/uploads/EP-2050_SeriesSpecifications.pdf
   
  http://ep2000.com/uploads/EP_Ground%20Filter.pdf


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## Uncle Erik

First, you need to be sure that it is noise on the power line. EFI/RFI will get in through cables and sometimes _directly_ into the amp itself. If it is getting in directly, no power conditioner will remedy that.

Start by eliminating sources of RFI near your rig. Computers, cordless phones, cellphones, electric motors, dimmer switches, fluorescent lights, and much else radiate RFI. The best cure is distance. Get the equipment away from that stuff.

Also consider that your rig already has a power conditioner built in. Really. No one ever seems to pay attention to this, but the power comes in to a transformer. Then it is fed through a series of capacitors and diodes (sometimes tubes) and better amps will have chokes and regulation. The entire point of this is to remove noise from the line. Let me repeat that, _the entire point of this is to remove noise from the line._

Put in lay terms, most power conditioners are like buying a washing machine for your washing machine. It's like washing your clothes and then putting them through a second washing machine.

Which begs a question: why not just have one good washing machine? If your amp is permitting line noise, then you bought an amp with a lousy power supply.

People tend to buy anything where "someone hears a difference," so, of course, there are a bunch of unnecessary products out there backed by nothing more than testimonials. They don't exist to clean the power, they exist to clean out your wallet.

There are a few legitimate power-related products:

1. A surge suppressor. Meant as a backup to your fuse and well worth spending $10 on. Though if an electrical storm passes through, just unplug everything. Better safe than sorry.

2. An isolation transformer. Handy for solving ground loops, which most power supplies are not engineered to do. Do not buy some futzy "audiophile grade" isolation transformer. One for about $50 is fine; you'll find them built for hobbyists since they're also a good way to keep from frying yourself while working on electronics.

3. A RFI/EMI filter. Personally, I think this is best solved outside the amp, but I'll recommend it anyway because you can get one for $3-$5. Why not? It can't hurt.

But beware the bogeyman of power claims. A lot of nonsense is claimed to get your money. Just like anything else. You wouldn't buy the magic undercoating from a car salesman, would you? Same thing in audio. The difference is that audio is an order of magnitude more dishonest than car salesmen.


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## lag0a

I am not on a dedicated power line but a shared line so other electronics share the same power that should interfere with my system. Even if it is a dedicated line I fear that the power line noise comes from the power plant and the journey it takes to get to your home. The computer is my source so it can only be two feet apart from my DAC and my DAC is two feet apart from my headphone amp.
   
  My computer uses a switching power supply, my DAC a twisted pear linear regulated power supplies and power transformers, and no idea about my audio-gd c2c power supply. I just know my system can sound better since I've tried the Equitech balanced transformer but I had to sell it for various reasons. I don't know if it was because it was balanced or it was a transformer that weighed 20 lbs. I'm unfamiliar with how filters work.
   
  I've heard of AC isolation transformers like topaz but have never tried one. Do they make a buzz sound or overheat? I have a very old isolation transformer that is really loud and is very hot when you turn it on and use it.  Are they not energy efficient in how they work?
   
  Is an isolation transformer what I'm looking for? Should I try an Topaz isolation transformer? Should the capacity be twice than what I'm looking for? I have heard the capacity should be 10x than what you need to create a better soundstage for music with a very black background.
   
  You're talking about an isolation transformer with AC outlets but not built each one specifically into the wiring of my computer switching power supply, dac, and headphone amp, right?


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## DaveBSC

Quote: 





lag0a said:


> Hi.
> 
> I've heard about balanced transformers, power regenerators, double line ups, and power conditioners so which is the real cure for power line noise without contraining and restricting dynamics which I have experienced before in a monster cable power line conditioner. I have also tried an Equitech balanced transformer and it I loved how it gave a natural flow to the music and it drops the noise floor so I can hear details better, and for some reason a good power cable makes the Equitech sound better in my headphone setup, but it is really expensive.
> 
> I am wondering if there is a cheap alternative approach to cleaning power line noise with respect to clearing up sounds in your source introduced from power line noise. Why do power line conditioners differ so much in price point when they all do different things to clean up sound? Are there cheaper alternatives with a better and right approach since technology is changing but are we left with only the same methods for cleaning up power line noise?


 

 Line noise could be a number of factors - distortion of the AC waveform, small amounts of DC, or airborne noise such as EMI or RF. The idea that you get nice, steady, beautiful 120V from your socket is laughable, and the idea that only an exceptionally poor component power supply cannot "fix every problem" is a myth, as you've noted with your Equi=Tech experience.
   
  If you're comfortable with a bit of DIY, you can make your own "Hydra" power conditioner very much on the cheap. Shunyata uses Vishay noise suppression caps in their standard Hydra models that only cost a few dollars. You can buy a nice chassis and use your own outlets and wiring, or buy one with the outlets, wires, and IEC already there, and just add the caps, total cost $150 or so. The sound will be pretty much identical to a Hydra 2/4/6.
   
http://www.vt4c.com/shop/program/main.php?cat_id=1038&group_id=2&hit_cat=
   
  If you want a commercial product, you need to spend at least $500 or so on a B-P-T CPC or MajikBUSS to see real results. The Monster units and other cheap "conditioners" (should be read current stranglers) just make things sound worse. Computer style simulated sine wave UPS units a big no no.
   
  I use a B-P-T BP-1 Signature, which is a 7.5 amp balanced transformer, but also employs caps on each outlet and a few other tricks as well. The BP-1 has more than enough current available for headphone use, and the pricing is pretty reasonable. The Audience Teflon conditioners and the Running Springs Dmitri and Maxim are also exceptionally good, but they cost 5X as much as the B-P-T.


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## WarriorAnt

Quote: 





davebsc said:


> Line noise could be a number of factors - distortion of the AC waveform, small amounts of DC, or airborne noise such as EMI or RF. The idea that you get nice, steady, beautiful 120V from your socket is laughable, and the idea that only an exceptionally poor component power supply cannot "fix every problem" is a myth, as you've noted with your Equi=Tech experience.
> 
> If you're comfortable with a bit of DIY, you can make your own "Hydra" power conditioner very much on the cheap. Shunyata uses Vishay noise suppression caps in their standard Hydra models that only cost a few dollars. You can buy a nice chassis and use your own outlets and wiring, or buy one with the outlets, wires, and IEC already there, and just add the caps, total cost $150 or so. The sound will be pretty much identical to a Hydra 2/4/6.
> 
> http://www.vt4c.com/shop/program/main.php?cat_id=1038&group_id=2&hit_cat=


 


  you have a schematic for the DIY?


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## DaveBSC

Quote: 





warriorant said:


> you have a schematic for the DIY?


 

 This is from 10 audio's description on what's in the Hydras and how to do one yourself:
   
  "There were also Okaya noise suppression capacitors on each AC outlet (the black rectangular blocks in the images), which cross referenced to Vishay/Roederstein part number F17104101000. These were installed with one lead attached to the AC outlet "hot", and the other lead was connected to "neutral".
  In summary, the “7-element Venom filter” was a varistor and three (or two) noise suppression capacitors. If we include the AC outlets and circuit breaker, we arrive at a parts count of 7."
   
  "I first installed the Vishay noise suppression capacitors across the AC outlets, one capacitor per outlet as seen in the Shunyata units. (The Vishay units are grey in color where the Okaya part is black.) This required drilling small holes in the rear plastic of the outlet to allow the wires to fit easily and neatly. The wiring was replaced next. It was soldered in place on the IEC receptacle and I used the screws on the AC receptacles. I made the decision to not wire the circuit breaker as it certainly could not improve the sound of the unit. I then secured the capacitors to the outlets with RTV 66B clear silicon adhesive. Although RTV 66B has a rather unpleasant odor when first applied, after it dries to a rubbery consistency it is completely odorless. RTV is useful for many different applications: even though I buy it at an auto parts store, I doubt I have ever used it for any car repairs. I left intact the stock green/yellow ground/earth wiring."
   
  "And the results? After using the two power conditioners with different components – both tube and solid state – and at different times of day and night, I reached the conclusion that the "DIY Hydra" was a sonic twin to the production Shunyata Hydra 4, taking into account the additional purity provided by eliminating the varistor in my "DIY Hydra". I found that similar performance to a $700 manufactured product could be obtained for an expense of roughly $100 and some time and effort."
   
  The author then adds: "For a very inexpensive, "bargain basement" power strip with significant noise reduction, I simply added one Vishay noise suppression capacitor across each AC outlet in a Home Depot-sourced 6-outlet metal enclosure power strip with excellent results. Although this basic strip does not have any cryo or hospital grade audiophile-approved parts inside, it comes quite close to the performance of the "DIY Hydra".
   

   

   
  Link: http://www.10audio.com/diy_power_conditioner.htm


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## WarriorAnt

Kool, Thanks.


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## lag0a

Does anyone have a link to buy the caps? Are they the best noise suppression caps for audio purposes you can buy?


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## DaveBSC

Quote: 





lag0a said:


> Does anyone have a link to buy the caps? Are they the best noise suppression caps for audio purposes you can buy?


 

 Mouser electronics carries them. They are definitely not the best caps available to use in a line conditioner, I think this was just an attempt to show that 1: the standard Hydra models are kind of a rip off and 2: you can make your own cheaply and easily. Making your own Audience AR conditioner with Aura Teflon caps would likely sound considerably better.. but would be quite a bit more involved.


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## lag0a

http://www.laventure.net/tourist/caps.htm#A
   
  Would it be too extreme to use a mundorf supreme capacitor as an ac line filter? I don't know if it does noise suppression.


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## fubar3

2 questions: (1) how do you know that noise you hear is from the power line?  (2) Why does noise from the power-line or anywhere else want to flow through your equipment?  Every piece of wire in the world is an antenna so noise on the power line is a given, but this noise only becomes a problem when there is a path for it.


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## lag0a

1) Well, A few examples would be my headphone system plugged into the Equitech, underclocking and undervolting my CPU in my computer affected the sound in my headphone system, and using a separate power supply for my hdds and fans cleared away this annoying sound I had in my headphone system.
   
  2) I think when the power is delivered to your home from your local power plant it goes through this long journey that is susceptible to noise (noise as in a host of nasty things that affect power that isn't harmful enough to prevent you from powering your equipment) then the power is shared in your neighborhood and also shared in the same circuit in your house.
   
  Has anyone heard or tried of this product?
http://arraysolutions.com/Products/nqnaclinefilter.htm
   
  You can use 9 different noise suppression capacitors and 4 toroidal core in one power line? How does this work? Is this product more effective than using one super expensive capacitor as an ac line filter?
   
  I also just found this article.
http://lampizator.eu/AC%20FILTER/SILK/FILTER.HTML
   
  I'm getting a headache. How many AC filter designs can you come up with? Which is the best method so far?


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## DaveBSC

Quote: 





lag0a said:


> I'm getting a headache. How many AC filter designs can you come up with? Which is the best method so far?


 

 A lot. I don't believe there is a "best" method, any more than there is a "best" type of loudspeaker design. Magnepan, Soundlab, and Dynaudio would all answer that question very differently. Balanced transformers are effective, and 7-8 amp versions support enough current to power headphone systems. I like B-P-T units because they use high quality Piltron transformers and let you decide what other additions you want, even down to wiring. There's also no dealer margins as with brands like Silver Circle. The downsides are that some transformers can hum if too much DC is present, and 15 or 20 amp capability means putting up with 70+ pounds. 
   
  Audience conditioners are the best of the all-cap models. The standard versions are good, but not incredible, mainly due to Auricaps being good, but not incredible. The Aura Teflon caps are a different story, but the price premium is considerable.
   
  Running Springs and Isotek go yet another route with inductor based filter networks. The lower end models are decent, but it seems like you need to spend $3K+ with these brands to really get anywhere.
   
  Then you've got the AC regenerators. My personal experience with this type has been generally negative. Active AC regeneration is not any kind of holy grail, despite the marketing materials.
   
  Yet another route are the oddball conditioners like the Audio-Magic acrylic boxes, and the Synergistic Powercells. I don't have any experience with these, but I tend to prefer products that are a bit more grounded in terms of what they actually claim to do.
   
  Finally, there's the purely passive "noise compound" conditioners from Acoustic Revive, and the new Shunyatas. I'd probably skip these.


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## lag0a

Have anyone tried a balanced power transformer with an AC line filter or RFI filter? Does it clean more power line noise and make your audio system sound better than using the balanced power transformer by itself? I know some balanced power transformers have filters been in but how would that compare to some standalone AC line filters or RFI filters?


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## lag0a

The more I read about AC line filters it all seems like a game to me that adding more makes the sound in your audio system sound better to no end. It seems like no one knows exactly how much noise and what kind of noise, and how to get rid of the noise completely. It seems you can only lower the noise but not completely capture and trap it then dissipate it through heat or something.


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## DaveBSC

lag0a said:


> The more I read about AC line filters it all seems like a game to me that adding more makes the sound in your audio system sound better to no end. It seems like no one knows exactly how much noise and what kind of noise, and how to get rid of the noise completely. It seems you can only lower the noise but not completely capture and trap it then dissipate it through heat or something.




I've actually noticed a significant decrease in performance from having two different types of noise reduction that were incompatible on the same circuit. The Audience conditioners and the PS Audio Noise Harvesters do not get along. Awhile back I was using an Audience Ar1p, and when I plugged in only a single Noise Harvester, the sound worsened substantially. It wasn't even close. I sold the Noise Harvester the next day. I wish there was an easy "just get this and you're done" answer, but there isn't. 

For my setup, my BP-1 works very well, and for the $330 or so that I paid for it, it's untouchable. A new one would be roughly $1200, and there's a few other conditioners I'd like to check out at that price level, like the UberBUSS. Still, even at $1200 I think the BP-1 is a good buy.


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## zilch0md (Jan 7, 2018)

Late to the party:







*UPDATED* this post on 7 January 2018, to withdraw my prior, misleading contention that isolation transformers with Floating-Neutral Secondaries attenuate Normal-Mode noise, instead of Common-Mode noise. After a great deal of research, I'm now convinced that Floating the Neutral of the Secondary neither prevents Common-Mode noise reduction, nor allows Normal-Mode noise reduction. *In short: All isolation transformers attenuate Common-Mode noise, whether the Secondary's Neutral is Floating or Grounded. *(Keep reading.)


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