[Soundminded]

The main reason you need effective power line conditioning is simple.  Aside from voltage issues, there is a ton of distortion in the power line.  Some from the generation of the power, other from things plugged in on your nearby circuit. (i.e. your neighbors arc welder, your fridge, etc etc)  You can easily see and measure this with a Fluke AC distortion meter if that floats your boat.

The power supply in your component, depending on how good it is will take out some to most but not all of this, so the remaining distortion components get amplified by your gear, which leads to that "grainy" sound everyone talks about.

Removing this with a good power line conditioning system results in a grain free presentation.

While you can argue about this until the cows come home, you need only listen for about 30 sec to get the picture.

If the power line conditioning solution you choose, removes the noise from the system, does not compromise tonality or dynamics, you've got it right.

If you eliminate noise but affect the music negatively, you've got it wrong.

In all the time spent arguing about this, a demo could easily have been done.

I highly suggest a few auditions and to get some hands on experience.

The main reason you don't need a power line conditioner is that your electonic equipment doesn't operate on AC, it operates on DC. The first thing after the power on off switch is a rectifier that converts AC to DC. Then a large capacitor and sometimes and inductor filter out all ripples. And then if you have a really good one it uses a voltage regulator to assure that the output voltage to the rest of the equipment remains constant no matter what the input voltage variations (within limits.)) The larger the power supply compared to the load it will be required to supply, the less it is affected by variations in the input power. The problem usually doesn't stem from the input line voltage but from the inadequacy of the equipment's own power supply. If a power conditioner improves your equipment, a better power supply will do the same at far less cost. If that is the case, chalk it up to the shortcomings of the engineer who designed your equipment. He cut the wrong corners to keep the price at an acceptable point.  I improved the sound of my preamplifier just by replacing the power supply's filter capacitor with one three times as large.

[Netdewt]

I have been looking into this also. I'm getting hums from my 2 year old Jolida, and I'm thinking maybe if the power was cleaner...

[Geardaddy]

So voltage fluctuation is the only issue?  What about "distortion"?

[Soundminded]

So voltage fluctuation is the only issue?  What about "distortion"?

"What about distortion?"

Not really an issue. The filter network in a power supply, usually a large capacitor but possibly an inductor as well filters out harmonic products generated by other sources. The specifications of importance in a power supply include ripple (AC voltage superimposed on the DC output) which should be low, and line and load regulation. Line regulation refers to how much the DC voltage output changes with changes to AC input. Load regulation refers to how much the DC output voltage changes with increasing load current drawn from it. Brute force regulation relates to the degree of overdesign of the power supply for its intended load. This can vary all over the place. One measure of how good equipment can be is related to how much it weighs. A heavy transformer and large filter capacitors are a good sign the designer knew that no piece of equipment can be better than its power supply. Another specification of value is slewing rate, that is how fast the power supply can deliver current when the demand on the load changes.  Compensation for a poor power supply by trying to condition input power is invariably far less effective and far more expensive than designing a very conservatively rated power supply for its purpose in the first place. It's at best a poor patch.

[rollo]

  I will agree that the better designed  the power is the better the overall sound. If ones component is designed with that in mind a PC will offer little.
 Saying that our experience with PC has been a mixed bag. Not all are equal. Some components just do not like power conditioners or have little affect. Others are improved. Or they just sound different. 
  What we can all agree about is that clean power is what we want. In theory noise reduction in the power can be accomplshed in many ways. However does the end result in a different sound. Science says no but our ears say different. Everything you plug in has an audible affect on the music. Why ? Science can not answer that yet.
  We look at it this way. Our ears are our test equip. Subjective yes but thats all that matters. All the theory and proper engineering has an end result . THE SOUND. Yes the sound created with ones system in ones room.
  Theory is needed to design anything but the proof of the pudding is the sound created. Just try one in your system and determine the end result. really that simple.



charles
SMA
 

[grsimmon]

"What about distortion?"

Not really an issue. The filter network in a power supply, usually a large capacitor but possibly an inductor as well filters out harmonic products generated by other sources. The specifications of importance in a power supply include ripple (AC voltage superimposed on the DC output) which should be low, and line and load regulation. Line regulation refers to how much the DC voltage output changes with changes to AC input. Load regulation refers to how much the DC output voltage changes with increasing load current drawn from it. Brute force regulation relates to the degree of overdesign of the power supply for its intended load. This can vary all over the place. One measure of how good equipment can be is related to how much it weighs. A heavy transformer and large filter capacitors are a good sign the designer knew that no piece of equipment can be better than its power supply. Another specification of value is slewing rate, that is how fast the power supply can deliver current when the demand on the load changes.  Compensation for a poor power supply by trying to condition input power is invariably far less effective and far more expensive than designing a very conservatively rated power supply for its purpose in the first place. It's at best a poor patch.

Agreed.  Thank you for the sanity.   And this, dear reader, is why well designed products from a reputable company like Bryston specifically state (to the effect of)  'do not plug this amp into a power conditioner,  it will do nothing to improve the sound,  we already built the power supply and internals to remove line noise before it exits the amp.'

There have been no magical "advances" in power delivery or management since 1990.   The only thing that has changed (exploded, actually) is cable and 'power' marketing,  and plenty of poorly designed/executed products on the market.  There's a sucker born every minute,  and many a company loves nothing more than a sucker with money to burn.   Now,  let's see how long my post lasts before it is considered "problematic" and deleted 

[Nyal Mellor]

Agreed.  Thank you for the sanity.   And this, dear reader, is why well designed products from a reputable company like Bryston specifically state (to the effect of)  'do not plug this amp into a power conditioner,  it will do nothing to improve the sound,  we already built the power supply and internals to remove line noise before it exits the amp.'

There have been no magical "advances" in power delivery or management since 1990.   The only thing that has changed (exploded, actually) is cable and 'power' marketing,  and plenty of poorly designed/executed products on the market.  There's a sucker born every minute,  and many a company loves nothing more than a sucker with money to burn.   Now,  let's see how long my post lasts before it is considered "problematic" and deleted 

Bryston do market a power conditioner (an isolation transformer) made for them by Torus. Having compared a PS Audio P5 to a Torus RM5 in my system I have to say the isolation transformer approach SOUNDS better. I strongly believe it is related to ability to supply the system with the current draw it needs. My theory at the moment, which it should be possible to measure given the right set of test equipment (I am just waiting on a current probe suitable for the task to be delivered), is that it is the limiting of current peaks which is one difference across the power conditioning technologies.

[mr_bill]

Good for me - I just bought Wig's Torus CS15 and am eager to try it in my system!   I have had no power conditioning in my system to date, so this will be a first and I have a high end 2 channel system.

[grsimmon]

Bryston do market a power conditioner (an isolation transformer) made for them by Torus. Having compared a PS Audio P5 to a Torus RM5 in my system I have to say the isolation transformer approach SOUNDS better. I strongly believe it is related to ability to supply the system with the current draw it needs. My theory at the moment, which it should be possible to measure given the right set of test equipment (I am just waiting on a current probe suitable for the task to be delivered), is that it is the limiting of current peaks which is one difference across the power conditioning technologies.

I could be wrong but I believe that Bryston and Torus are no longer 'joined'.  Regardless,
agreed,  and I too use an isolation transformer to power my entire system.   But for the uninitiated, it is important to point out that this is a different ballgame than magical "power conditioning."   

[Folsom]

I disagree that removing AC fluctuations is more important than filtration. In fact if rectification and DC side capacitors where good enough by themselves then the Bybee Music Rails wouldn't do anything (and not testimonials have yet to show they don't, that I have found). Furthermore good power filters remove more than "grainy" sound. A lot of what you are hearing that doesn't sound ideal, is not audibly detectable. You can only realize it is different when you remove a power conditioner, and notice the difference. It takes several days before you adjust to the subtleness of it, but you may never be able to do without again.

One of the fellows who got a power conditioner from me has a Bryston amplifier. The rest of his gear is Bel Canto's higher end stuff. I almost couldn't get my prototype back from him... Bryston can say whatever they want, ears dictate more.

[Diamond Dog]

For the sake of clarity, here is Bryston's current (  I made a funny ! ) position on the use of power conditioners with their gear. This is directly from the 7B SST2 manual:

A/C POWER CONDITIONERS
Bryston urges caution in choosing a power conditioner for your audio/video system. Large power amplifiers can draw very
substantial current from the wall plug, and many so-called power conditioners can in fact hinder the supply of current by
inserting resistances in series with the line cord. However, there are now power conditioners that can reduce or eliminate
RF and 'hash' from the AC supply and may actually improve current delivery to your system. This type of power conditioner
(exemplified by 'TORUS' Power Conditioners) uses the energy storage in a large toroidal transformer to provide high
instantaneous power and reduce the substantial AC output resistance of the wall socket and house wiring. This resistance
can be in the range of 0.5 to 1 Ohm and is typically reduced to only a few milli-ohms by the Power Conditioner. That in turn
considerably reduces Voltage drop in the power line on high current surges and quite substantially increases the stability
of the power line improving audio (and video) focus, precision and clarity.

D.D.

[Soundminded]

For the sake of clarity, here is Bryston's current (  I made a funny ! ) position on the use of power conditioners with their gear. This is directly from the 7B SST2 manual:

A/C POWER CONDITIONERS
Bryston urges caution in choosing a power conditioner for your audio/video system. Large power amplifiers can draw very
substantial current from the wall plug, and many so-called power conditioners can in fact hinder the supply of current by
inserting resistances in series with the line cord. However, there are now power conditioners that can reduce or eliminate
RF and 'hash' from the AC supply and may actually improve current delivery to your system. This type of power conditioner
(exemplified by 'TORUS' Power Conditioners) uses the energy storage in a large toroidal transformer to provide high
instantaneous power and reduce the substantial AC output resistance of the wall socket and house wiring. This resistance
can be in the range of 0.5 to 1 Ohm and is typically reduced to only a few milli-ohms by the Power Conditioner. That in turn
considerably reduces Voltage drop in the power line on high current surges and quite substantially increases the stability
of the power line improving audio (and video) focus, precision and clarity.

D.D.

Bryston got it wrong. The impedance ratio is directly related to the turns ratio. Since the output and input voltages must be the same, 120 volts the ratio must be 1:1

http://nuclearpowertraining.tpub.com/h1011v4/css/h1011v4_46.htm

Good try though. 

[Speedskater]

Bryston got it wrong. The impedance ratio is directly related to the turns ratio. Since the output and input voltages must be the same, 120 volts the ratio must be 1:1

This may be one of their automatic line voltage adjusting units, if so it will work. That is, it will keep changing the transformer tap to keep the output voltage steady. Now the question is - can the unit do it with high power audio amplifiers? A big power amp only draws high current through a small part of each AC power line cycle.

I went to the 'TORUS' Power Conditioners web page and it's mostly marketing claims!  No real technical tests or specs.  Oh, and nothing about NEC, UL or CSA testing and listing.

[Mitsuman]

They are part of Plitron Industries, a long-time and respected company. They certainly have approvals for their industrial products anyway. 

Plitron works closely with safety agencies to ensure all products meet applicable standards.  Plitron products are approved to the following UL, CSA, and IEC standards:

Toroidal transformer construction:  UL506, UL1411, CSA 22.2 No 66-1988
Medical transformers and power isolation units:  UL 60601-1 (IEC Standard), CSA 601.1
CE & RoHS compliant
In Ontario, ESA

[Soundminded]

This may be one of their automatic line voltage adjusting units, if so it will work. That is, it will keep changing the transformer tap to keep the output voltage steady. Now the question is - can the unit do it with high power audio amplifiers? A big power amp only draws high current through a small part of each AC power line cycle.

I went to the 'TORUS' Power Conditioners web page and it's mostly marketing claims!  No real technical tests or specs.  Oh, and nothing about NEC, UL or CSA testing and listing.

There's lots of talk lately about using an isolation transformer with an ungrounded secondary. That is not legal for this type of transformer in the US unless it is built into the equpment itself, as part of a power distribution network it does not meet NEC requirements. It is technically classified as a "derived source."

Some people claim that a large electrolytic capacitor such as is used in power supplies will not shunt RF noise. I'm not getting into that debate but the cheapest and easiest way to remedy that if it's so is to connect a low value capacitor, say 0.47 mfd across the power supply output, that will be an effective shunt. (This technique is also used by some speaker designers for polypropylene caps in crossover networks who claim polys don't function at voltages near zero volts either.) This will surpress any rf noise superimposed on the DC side. All that is required is that the capacitor have at least as high a voltage rating as the power supply caps and if it is a polarized type that it be connected in the same sense. It should take no more than five or ten minutes for anyone who can handle a screwdriver and a soldering iron and it should cost under $1. Not much profit to be made from it though.

[Folsom]

For the sake of clarity, here is Bryston's current (  I made a funny ! ) position on the use of power conditioners with their gear. This is directly from the 7B SST2 manual:

A/C POWER CONDITIONERS
Bryston urges caution in choosing a power conditioner for your audio/video system. Large power amplifiers can draw very
substantial current from the wall plug, and many so-called power conditioners can in fact hinder the supply of current by
inserting resistances in series with the line cord. However, there are now power conditioners that can reduce or eliminate
RF and 'hash' from the AC supply and may actually improve current delivery to your system. This type of power conditioner
(exemplified by 'TORUS' Power Conditioners) uses the energy storage in a large toroidal transformer to provide high
instantaneous power and reduce the substantial AC output resistance of the wall socket and house wiring. This resistance
can be in the range of 0.5 to 1 Ohm and is typically reduced to only a few milli-ohms by the Power Conditioner. That in turn
considerably reduces Voltage drop in the power line on high current surges and quite substantially increases the stability
of the power line improving audio (and video) focus, precision and clarity.

D.D.

Depending on the power conditioner it is easy to have filtration and a zero resistance option. (I prefer it with certain amplifiers, especially high powered ones). I usually like to offer low resistance, and no resistance options on a conditioner along side the high filtration sockets. It depends though, different people will want different things for different setups. This one of the problems with something like an Audience Adept, all the sockets do the same thing.

[Speedskater]

They are part of Plitron Industries, a long-time and respected company. They certainly have approvals for their industrial products anyway. 

I thought that they just used Plitron transformers, but I see that they both have the same address. Which by the way is only a few blocks from the CSA office. Notice how well documented the professional products are.

[Speedskater]

Depending on the power conditioner it is easy to have filtration and a zero resistance option. (I prefer it with certain amplifiers, especially high powered ones). I usually like to offer low resistance, and no resistance options on a conditioner along side the high filtration sockets. It depends though, different people will want different things for different setups. This one of the problems with something like an Audience Adept, all the sockets do the same thing.

How do you do that and still have an effective low frequency filter?

[Soundminded]

Depending on the power conditioner it is easy to have filtration and a zero resistance option. (I prefer it with certain amplifiers, especially high powered ones). I usually like to offer low resistance, and no resistance options on a conditioner along side the high filtration sockets. It depends though, different people will want different things for different setups. This one of the problems with something like an Audience Adept, all the sockets do the same thing.

I for one would like to know how to get zero source impedance. When I learn that I can set Thevenin's theorum aside.

http://en.wikipedia.org/wiki/Th%C3%A9venin's_theorem

BTW if a source really did have zero source impedance it would be able to supply an infinitely large current and no circuit breaker made could protect against a short circuit in it. Well maybe a vacuum breaker...and then again....

[Speedskater]

BTW if a source really did have zero source impedance it would be able to supply an infinitely large current and no circuit breaker made could protect against a short circuit in it. Well maybe a vacuum breaker...and then again....

Not really. "zero source impedance",  "infinitely large current" and "circuit breaker" are three different things.  If a circuit has the same supply voltage at zero load and at full load it has "zero source impedance".