[KeithR]

Let's start a thread on obviously one of the "hot" trends in audio.  What kinds of power conditioning have worked for you, and which products do you recommend.  What differences have you noticed, both on audio and video products, and which was more significant.

I just got a Sound Application XE-12S in late last week, and going to start A/Bing it against my trusty Trip-Lite highly recommended on AA.  People have said the Sound App is one of the few that doesn't impede the current/sound, and friends of mine swear by it.  We will see, and of course i will post back soon hopefully...

[RussKon]

many people ignore the fact that power conditioners were created to "fix power problems"....

in actual practice, most people really have pretty good power...(at least in the u.s.)....

i doubt whether a power conditioner will greatly improve your sound in every situation.....

however, i do heartily recommend good surge protection in ALL SYSTEMS...

[Psychicanimal]

in actual practice, most people really have pretty good power...(at least in the u.s.)...

Dude,

I've never seen anything so out of contact with reality!

[RussKon]

in actual practice, most people really have pretty good power...(at least in the u.s.)...

Dude,

I've never seen anything so out of contact with reality!

out of contact with reality??? ....well let's see....... last year i sold over $1,000,000 in pro/commercial audio gear at the distributor level....i do know a little about what i'm talking about....

and just for your information....alot  of the "power conditioners" on the market consist of  four or five mov's (a grand total of $1.50 worth of parts)

so..."dude".... please explain your position....

[Rocket]

hi guys,

i can't comment about power conditioners but can talk about clean power.

i have an n.e.w. dc-66 amplifier which is a battery powered amplifier which is powered by 4 12v 33 amp hour panasonic batteries.  i have had the ac and dc version of this amp and cannot hear any differences in sound quality.

just my take on this.

regards

rocket

[Jay S]

Power quality can have a significant difference on sound quality if you are able to listen to details, particularly if you have a system of above average resolution.  Do you encounter this situation much in pro/commercial applications?  My limited exposure (as a consumer) is at concerts and conventions, where volume, rather than ability to recreate small nuances (vocal inflections, emotion, spacial cues, etc) is the prime consideration.  I ask this as a sincere question rather than an attempt to minimize the value of your experience as a pro/commercial audio distributor.

Personally, I have a balanced power supply at home, which feeds my entire audio system.  It uses common mode rejection to reduce power line noise.  Rather than MOVs it uses big heavy transformers.  Balanced power is recommended as part of the National Electrical Code (do check the exact name) so I do believe that is well based in fact rather than a heavy dose of snake oil.  I have found that supplementing this with bybee filters further reduces noise.  Now, I will admit that many are skeptical about the "science" behind Bybee filters.  I am in no position to evaluate its scientific merit, but I have heard a difference in my own system which make me comfortable spending my own money.  

I have also heard a capacitor based filter (the DeZorel Audio Reference Senior/GND) significantly help a friend's system.  A smaller version of that filter also produced worthwhile benefits in my system, though it didn't have enough outlets to plug my system in to.  

Another very interesting technology to me is parallel filters.  We have been very surprised at how big an improvement the Quantum Symphony Pro has produced in my home, Guan's and icefox's.  Bass tightened up, the midrange got clearer and purer, treble became delicate and airy and lost its stridency, soundstage got much wider and deeper, etc.  Best of all, parallel filters can't limit the current delivered to your equipment as they are, um, in parallel, rather than in series with the flow of current to your equipment (all power filters which are in series have the potential to limit current flow).  

The most expensive solution out there is power regenerators, which take in "dirty" AC, convert it to DC, then recreate a "perfect" AC sine wave which is then fed to your equipment.  Many people love them, but they do tend to be rather large, heavy, expensive and current limited.  Some also note colorations to the sound.  

In all cases, its best to try before you buy.  Changing power filters and cables don't always result in large changes in the sound.

[RussKon]

jay,

thanks for your reply..... i agree that balanced power and certain isolation transformers do clean up the power..... in some situations.... some of my customers pro installs required isolation transformers to solve sertain problems in the install...... but this pretty rare....

perhaps your closing remark is the best advice on any power conditioner/power cords...

"In all cases, its best to try before you buy. Changing power filters and cables don't always result in large changes in the sound."
 

the biggest problem out there is that many companies are marketing "power conditioners" that produce little or no change in the quality of the sound.....

and by the way.... i have over 15 different customers who install home theatres.... several of them have systems that start at $60,000 and go up from there..... so yes.... these are very critical and high end listening setups.... and they use minimal power conditioning...if any....

they do however offer a full warranty against all surges including lightning strikes if the customer opts for the surge-x surge protection.....

www.surgex.com

additionally..... how many high end amplifier companies recommend plugging their amplifers directly into the wall outlet???....bryston and krell are just a couple that have that recommendation in their owners manuals...

[KeithR]

Most amps, cdps, preamp makers don't recommend anything but stock cords etc.  This is more for liability sake than anything else i believe.

[RussKon]

Most amps, cdps, preamp makers don't recommend anything but stock cords etc.  This is more for liability sake than anything else i believe.

they recommend that because there is no scientific way to measure any differences in power cords.....

i know that the above comment will bring about many people claiming to hear "wonderful" improvements in their systems with aftermarket power cords....

but the simple truth is that there is NO ELECTRICAL DIFFERENCE THAT IS MEASURABLE!!!! if there was a measurable difference, it would be published as "proof" that that particular cable was better....

and besides....what manufacturer would recommend any product over his own product???....

liability is not an issue if the power cord is removable..... if the replacement cord is rated for the same amount of power as the original there is no liability issue....

[satfrat]

many people ignore the fact that power conditioners were created to "fix power problems"....

in actual practice, most people really have pretty good power...(at least in the u.s.)....

i doubt whether a power conditioner will greatly improve your sound in every situation.....

however, i do heartily recommend good surge protection in ALL SYSTEMS...

                 Hi,  First my position, I`m glad I was never a customer of yours (no offense) and second, you are definitely in the minority in your beliefs on clean power and the need of power conditioners in one`s system. The reason for my position is clear to my ear. I had no noise in my sound, never had. No problems, I was happy with my sound because it was what I as use to. A year ago after being introduced to the internet and scanning the forums, I learned of balanced power. I took a chance on www.b-p-t.com , mainly of their 30 day guarantee and my life has never been the same. I went from a sports junkie to an audio enthusiest overnight. My ancient speakers took on a new life and I was hearing things that ROCKED MY WORLD! Since then I`ve had my BP2.5 maxed out with upgrades and further lowered my ground noise (funny, never thought I had any!) with extensive use of Bybee`s thruout my system from the outlet to the speakers. I`ve gotten to the point where I`m wondering what I`d be hearing with real speakers because I`m hypnotized from these 18yr. old senior citizens. And to think that I would have missed out on all this if I`d been a customer of yours with a "good" surge protector. My suggestion to you is listen to Psychicanimal, you might learn something. Hell, listen to anyone here that has had the same experiences that I have had with the absense of ground noise in your so called "clean power". BPT BP2.5/maxed out and Bybee`s,,,, lot&lots of Bybee`s, that`s what I use. I`m done! Regards, Robin

[Mad DOg]

i didn't believe in power conditioning...thought it was just a bunch of baloney...after all electricity is electricity, right? and i was VERY happy with my system...

that is until another member brought over his Shunyata Hydra and we plugged it into my system...OMG!!! what i experienced was very similar to Satfrat's experience...the same member brought his Hydra over to John Casler's place and the difference it made was not as great as it was at my place. this experience made one thing very clear to me...power varies from home to home. in my case, i can really benefit from a good conditioner.

so bottom line is to try it yourself and see if it works for you.

[RussKon]

Hi,  First my position, I`m glad I was never a customer of yours (no offense) and second, you are definitely in the minority in your beliefs on clean power and the need of power conditioners in one`s system. The reason for my position is clear to my ear. I had no noise in my sound, never had. No problems, I was happy with my sound because it was what I as use to. A year ago after being introduced to the internet and scanning the forums, I learned of balanced power. I took a chance on www.b-p-t.com , m ...

ok...glad you can hear some difference.... but what is actually happening??? what is the measurable difference???   where can i hook up my 'scope or multimeter and see an electrical difference????  

how can you "lower the noise floor" if you never had any noise??????

"I`m glad I was never a customer of yours (no offense)"

in case you misread my posts..... i am a pro audio distributor... i do not sell to the public... only to dealers, contractors, and installers

maddog,

"the same member brought his Hydra over to John Casler's place and the difference it made was not as great as it was at my place"

this is one reason why power condtioners, power cords, etc. get no serious respect from electrical engineers..... LACK OF REPEATABILITY!!!

 one of the tennants of any scientific experiment is that it can be repeated at different locations - over and over.... if it can not be repeated, then it is not scientifically valid.....

and that is why you don't see any high end manufacturers of audio equipment incorporating "power conditioning" into their equipment...whether it's "balanced power" or whatever.... and most manufacturers go out of their way to tell you to plug the amplifier (for example) directly into the wall outlet....

[Jay S]

Hi Russ,

There was an interesting discussion on this topic a couple of months back, though unfortunately it generated rather quickly.  You are right that quantifiable differences are more robust than qualitative ones.  

That said, I believe that resistance and capacitance will vary from cable to cable, particularly when you measure terminated cables.  Empirical Audio's site speaks about this, and they publish measurements for all of their cables.  Audioengineer/Steve has made numerous posts here about measurements.  

There has been further discussion that the critical parameter can vary depending on the application.  In general, resistance is a critical parameter for power cables (as capacitors in power supplies need to get an instantaneous slug of current to rapidly charge them when they discharge).  Capacitance is critical in interconnects as energy storage can cause high frequency rolloff and phase errors.  

RFI/EMI also needs to be taken into account.  Many people ask critically (and rightly so) why a 6 ft power cable matters when you've got miles of cabling in the wall, in the mains, etc.  The answer seems to be that nearby electrical components in the system (e.g. a TV, a DVD player, a dac) can put out lots of EMI and a good power cable keeps EMI from other components out and keeps EMI produced by the connected component from spreading.  

Anyway, let's see if this discussion that go to the next level.  There is a lot that we still need to better understand.

[Dan Banquer]

The term Power Conditioner has really been misused from what I can gather. Most of this answer will hopefully address Russ Kon's concerns.
I will generally advocate High Frequency filtering on the AC line for the following reasons. Linear power supplies ( most of what we use in audio) have poor rejection at high frequencies. Semiconductor designed for low frequencies and the linear designs we put them in also suffer from poor rejection at high frequencies. This has been well documented by Analog Devices and the AES Journal.
In today's world with the proliferation of anything from computers, to wireless phones, and the overall increase in RF traffic; high frequency filtering of the AC line is now a must for anyone living in a suburban or urban area. This is not exactly expensive. The Dezoral filters have some of the best spec's I have seen to date, and the Tripplite Isobar Series is a good bang for the buck.
Power Line stabilization, (regulating the AC line voltage) should not be an issue for well designed equipment.
Isolation transformers should really only be used when then there is no alternative. If you have to use one, then what that is really telling you is that you have a ground loop somewhere in the wiring of your AC line or a miswired piece of equipment. The key thing to remember about an isoltion transformer is that it isolates hot and neutral from what ever you are connecting it to. The next key thing to remember is that neutral is connected to earth ground at the box. If wiring is crossed and hot is going to neutral and vice-versa than the best idea is to fix the wiring. Isolation transformers are expensive, drop a fair amount of AC line voltage especially during current peaks, and the big ones have a tendency to make you want to see a chiropracter after you have lifted one.
Hope this helps.

BTW: One of the major reasons that we can have so much high frequency content on the AC lines is that the utilities use transformers with a very wide bandwidth. This was done in the attempt to read meters using the AC line as a the "cable". If they used a much lower bandwidth, much of the high frequency content that can be on an AC line would be greatly reduced.

[Jay S]

Dan,

Do you have similar concerns re: balanced power supplies, which use transformers to reject power line noise?  I wonder since I decided against the DeZorel and got a balanced power supply instead.  I guess I could get the cheapest DeZorel (they aren't current limited anyway) and plug my balanced power supply into it and get a double benefit, though I would have more connectors in the AC path.  

My current plan is to "double up" on the benefits of balanced power and bybees by getting a bybee Nitro power cord (1 bybee for live, 1 for neutral) for my balanced power supply.

[DVV]

...the biggest problem out there is that many companies are marketing "power conditioners" that produce little or no change in the quality of the sound.....  

Russ, if you want changes BIG time for the better in ANY system you can put together, try a DeZorel PS3 or, better yet (but also more expensive), their Audio Reference and RP series. ESPECIALLY with tube gear, though big Krell, Levinson, etc, stuff will also benefit like you wouldn't believe.

I am not going to describe it again, because it's not my job to advertise and/or sell them, look over the thread on the group test. It will show you that they are merciless in exposing both the good and the bad; they can't make a poor system sound better, all they can do is enable your system to the best it can do.

Cheers,
DVV

P.S. I totally agree with you on the hype surrounding line filters - but these guys have been making them since 1975.

[Dan Banquer]

"Do you have similar concerns re: balanced power supplies, which use transformers to reject power line noise? I wonder since I decided against the DeZorel and got a balanced power supply instead. I guess I could get the cheapest DeZorel (they aren't current limited anyway) and plug my balanced power supply into it and get a double benefit, though I would have more connectors in the AC path.

My current plan is to "double up" on the benefits of balanced power and bybees by getting a bybee Nitro power cord (1 bybee for live, 1 for neutral) for my balanced power supply."
 
Hi Jay;
     One of the more interesting things about these "balanced" transformers that split the AC line voltage is that the transformers they are connected to in the equipment being used are not balanced. I am dubious at best about this stuff. And the same goes for "designer cords"
My advice is go with the DeZoral, use standard IEC power cords that are shielded, and a surge suppresor of some type. Use the surge suppressor in front of the Dezoral.

[JohnR]

BPT sounds better than DeZorel. Or at least, it did when I heard them.

[Jay S]

Hi Dan,

Thanks for the reply.  I don't have enough of an electronics background to see why it may be a problem that the downstream transformers in my equipment are not balanced.     As far as I know my balanced power supply supplies +110 on the Live line and -110 on the Neutral line, for a total voltage of 220v.  I was told that polarity is no longer an issue when components are plugged into a balanced power supply.  Given that balanced power has been written into the U.S. National Electrical Code, and is recommended for noise-sensitive applications, I feel like there must be something to the technology (though I continue to learn).  

On a practical level, I heard improvements in my system with both the DeZorel (an entry level model) and the Blue Circle Music Ring balanced power supply.  Plugging the Blue Circle into the Bolder Quantum Bybee power strip further improved the sound.... hence my overkill solution to triple-up!!  

[DVV]

BPT sounds better than DeZorel. Or at least, it did when I heard them.

A matter of taste. My experience is exactly the opposite, though I must add that I have heard an A/B comparison with just one model by BPT, owned by a friend of a friend. I would have preferred to have been able to compare them head to head in my own room, on my own system.

Cheers,
DVV