Experience with power conditioners?

[kennyb123]

44 minutes ago, gmgraves said:

 

How, pray tell, is a power conditioner going to impede an amp or preamp's ability to adequately handle transients. The very job of a power conditioner is to not have any high-frequency capability. In a perfect world, a power conditioner would pass 50-60 Hz and no other frequency. That's how it cleans up the mains. It strips away switching transients, line noise and RF interference, by not letting them pass the conditioner. 

 

Tell us then how you would implement a power conditioner that passes only 60 Hz absolutely perfectly - with no reactive losses whatsoever.  I can't wait to hear this.

 

Now back to the real world, I've attached a photo of a well-regarded power conditioner.  How could forcing a component to draw power through this not impede instantaneous current delivery relative to drawing the current directly from the wall?  

 

 

And as a point of contrast, here's the inside of the Denali:

 

 

This is the Denali model I have:

 

 

Shunyata places no reactive components in the signal path.  So no reactive losses.

[gmgraves]

4 hours ago, kennyb123 said:

 

Tell us then how you would implement a power conditioner that passes only 60 Hz absolutely perfectly - with no reactive losses whatsoever.  I can't wait to hear this.

 

Now back to the real world, I've attached a photo of a well-regarded power conditioner.  How could forcing a component to draw power through this not impede instantaneous current delivery relative to drawing the current directly from the wall?  

 

 

And as a point of contrast, here's the inside of the Denali:

 

 

This is the Denali model I have:

 

 

Shunyata places no reactive components in the signal path.  So no reactive losses.

Did you not see where I said "...in a perfect world"?. Last time I looked, we don't live in one of those. Of course, no filter will pass only 50 - 60 Hz. That doesn't mean that such a filter isn't a desired goal. It just isn't an achievable one.  

 

None of that means anything. All your power supply in your amplifier circuits wants is 50-60 Hz at enough current to properly operate the amplifier. If the power conditioner doesn't supply enough current, it's too small for the job. It's that simple.

[kennyb123]

1 hour ago, gmgraves said:

If the power conditioner doesn't supply enough current, it's too small for the job. It's that simple.

 

I would rephrase that: if the power conditioner doesn't provide sufficient current quickly enough, it could be sucking the life out of your music.

 

You seem to be avoiding any mention of the speed of power delivery.  Why is that?  Do you not think it's important for an amp to be able to respond instantly to meet the demands of the music?  Have you never heard how a system benefits when efforts are made to improve transient current delivery?  

[STC]

29 minutes ago, kennyb123 said:

I would rephrase that: if the power conditioner doesn't provide sufficient current quickly enough, it could be sucking the life out of your music.

 

+1

 

IMO, power conditioner affects the bass. It can be good or bad depending on your room acoustics. Generally, most audiophile users system output more bass than necessary for music which can be nice depending on the type of genre you like but at the same time it can make your system's sound muddy. By adding power conditioner, the bass is slightly attenuated and this would make your system a little better.

 

I used to have Watsford stabilizer connected to constant voltage Cetronics in series. It sounded really good but after room acoustics treatment I do not use them anymore. YMMV.

[Speedskater]

3 hours ago, kennyb123 said:

 

I would rephrase that: if the power conditioner doesn't provide sufficient current quickly enough, it could be sucking the life out of your music.

Look inside a power amp, see those big can shaped things? They are called capacitors, they store DC, enough DC to get the amp through many power line cycles.

[Speedskater]

9 hours ago, kennyb123 said:

Tell us then how you would implement a power conditioner that passes only 60 Hz absolutely perfectly - with no reactive losses whatsoever.  I can't wait to hear this.

Unfortunately most audiophile power conditioners don't do a very good job of filtering anything much below 100 kHz.

[Speedskater]

On power conditioner's line filters, Bill Whitlock writes:

 

Virtually all AC power-line filters, whether very simple or complex, have trivial attenuation below 30~50 kHz

 

A power-line filter that might help would be as big as a refrigerator.

 

Serious attenuation would need to begin at a few hundred Hz, not tens of thousands!

[kennyb123]

3 hours ago, Speedskater said:

On power conditioner's line filters, Bill Whitlock writes:

 

Virtually all AC power-line filters, whether very simple or complex, have trivial attenuation below 30~50 kHz

 

 

That may be right. 

 

One counterpoint:  Richard Marsh designed the parallel conditioners for both MIT and Monster Cable at one time.  He claims attenuation by 25-30 dB at 1 KHz:

https://www.google.com/patents/US5227962.  I used to own the conditioner he designed for MIT.  It was about 3% as effective as my Denali.  (I'm being facetious with that number - the Z-Stabilizer offered a very subtle improvement.  The Denali's improvement was easy to hear.)

 

Shunyata argues that the what's more important to address than incoming noise is the harm is done by our components themselves, that dump all kinds of noise onto the line.

 

The Denali features component-to-component filters that isolate noise from one component to another component.  The spec they publish for noise suppression between Zone 1 and Zone 2:

 

> 60db (500 Khz - 10 MHz)
> 24db (100 Khz - 30 MHz)

 

As far as noise suppression from the inlet:

 

Between inlet and Zone 1 or Zone 2:

> 25db (500 Khz - 30 MHz)

 

Zone 3 is the high current outlet meant for amps, so even less suppression is applied there:

 

> 15db (100 Khz - 30 MHz)

[gmgraves]

8 hours ago, kennyb123 said:

 

I would rephrase that: if the power conditioner doesn't provide sufficient current quickly enough, it could be sucking the life out of your music.

 

You seem to be avoiding any mention of the speed of power delivery.  Why is that?  Do you not think it's important for an amp to be able to respond instantly to meet the demands of the music?  Have you never heard how a system benefits when efforts are made to improve transient current delivery?  

 

I wouldn't re-phrase it. Current doesn't work that way. It's not the conditioner that needs to supply enough current fast enough, it's the design of the amp's DC power supply; in particular the filter capacitors that need to be able to supply the current "fast enough" to recover after a fast, high-power transient.

[Speedskater]

It's tricky and complicated to measure power line filters.

Different branches of electricity use different definitions for differential and common mode noise.

Richard Marsh was using a different type of measurement for a different type of problem.

[kennyb123]

1 hour ago, gmgraves said:

 

I wouldn't re-phrase it. Current doesn't work that way. It's not the conditioner that needs to supply enough current fast enough, it's the design of the amp's DC power supply; in particular the filter capacitors that need to be able to supply the current "fast enough" to recover after a fast, high-power transient.

 

Are you telling me that if I intentionally place a high impedance and highly reactive load between the amp's power supply and the wall outlet - this won't impact in any way the amp's ability to draw current quickly?

[gmgraves]

58 minutes ago, kennyb123 said:

 

Are you telling me that if I intentionally place a high impedance and highly reactive load between the amp's power supply and the wall outlet - this won't impact in any way the amp's ability to draw current quickly?

 

Yeah.. but why would you do that? But it shouldn't matter. A well designed amp will have huge filter caps in the power supply, and all the mains is doing is keeping them filled. A very crude analogy would be that of a trickle charger on a car battery. There's no way that the charger can supply enough current to light a headlight, much less turn the motor over, but the trickle charger can, over time, charge the car's battery enough that it can easily start the car, and run all the car's appliances. Why? Because you aren't relying on the charger to start the car, you are only relying on the charger to fill the reservoir. 

 

[kennyb123]

55 minutes ago, gmgraves said:

 

Yeah.. but why would you do that? But it shouldn't matter. A well designed amp will have huge filter caps in the power supply, and all the mains is doing is keeping them filled. 

 

 

First off, you've just acknowledged that placing a device between an amp and the wall outlet could impact the amp's ability to draw current quickly.  I used the extreme case just to get you to agree that it is possible - something you denied.

 

Secondly, there's really no point in me continuing from here.  You live in a world where everything is perfectly designed such that real world constraints don't exist.  

 

In your world:  

 

- amps can always perfectly draw current instantaneously - no matter what impedance is seen by the amp's power supply 

 

- power conditioners can't present an impedance to power supplies that can harm instantaneous current delivery in anyway

 

In my world neither of these are true. It's as if we live in different universes. I don't see how anything I've learned or experienced in my universe can apply in yours, so no point in continuing this.

 

I was wondering though if you could direct me to a portal that would allow me to move to your universe.  I could build a far better system in your universe as every component would work perfectly.  

[gmgraves]

48 minutes ago, kennyb123 said:

 

First off, you've just acknowledged that placing a device between an amp and the wall outlet could impact the amp's ability to draw current quickly.  I used the extreme case just to get you to agree that it is possible - something you denied.

 

Secondly, there's really no point in me continuing from here.  You live in a world where everything is perfectly designed such that real world constraints don't exist.  

 

In your world:  

 

- amps can always perfectly draw current instantaneously - no matter what impedance is seen by the amp's power supply 

 

- power conditioners can't present an impedance to power supplies that can harm instantaneous current delivery in anyway

 

In my world neither of these are true. It's as if we live in different universes. I don't see how anything I've learned or experienced in my universe can apply in yours, so no point in continuing this.

 

I was wondering though if you could direct me to a portal that would allow me to move to your universe.  I could build a far better system in your universe as every component would work perfectly.  

First of all, I don't know where you get the idea that I "live in a world where everything is perfectly designed..." Secondly, I have neither stated nor implied that "amps can always draw current instantaneously - no matter what impedance is seen by the amp's power supply". What I did say was that in a properly designed amplifier, instantaneous current delivery from the mains is simply not all that important, but steady current delivery is all that important.

 

And I agree that this is a useless discussion. I am not interested in pursuing this.

[jabbr]

1 hour ago, gmgraves said:

First of all, I don't know where you get the idea that I "live in a world where everything is perfectly designed..." Secondly, I have neither stated nor implied that "amps can always draw current instantaneously - no matter what impedance is seen by the amp's power supply". What I did say was that in a properly designed amplifier, instantaneous current delivery from the mains is simply not all that important, but steady current delivery is all that important.

 

And I agree that this is a useless discussion. I am not interested in pursuing this.

 

Yes, the current delivery capability of an amplifier PSU has to do with its output impedance -- this is generally dependent on caps & ESR. Well designed power supplies may have input chokes (google input choke filter power supply) which expressly limits the inrush current. The concept of instantaneous current delivery having to do with power "conditioning" is generally very misguided.

[fas42]

Getting conventional power supplies to work reasonably is not trivial - if one  ignores the gross over-simplification one reads in textbooks and investigates what actually happens in a real power amplifier, then it becomes quite a challenge to make them work properly. The Philips HT box I played with with years ago had most of the work done on the power supply feed area, getting it to run as cleanly as possible - which allowed the low powered amps to give of their best. A DIY chip amp I designed and built was 90% power supply, because getting the voltage rails super clean was key to making the sound work well.

 

This is why doing almost anything to the mains coming into a component changes the sound - the lack of attention to detail of the design of the supply circuit means that the rest of the circuitry inside is extremely sensitive to what the mains is like.

[Ralf11]

what actually happens in a real power amplifier?

[fas42]

19 minutes ago, Ralf11 said:

what actually happens in a real power amplifier?

 

The amount of energy needed to drive speakers with music having heavy bass content overwhelms the ability of the mains-transformer-smoothing caps to maintain delivery - the voltage rails sag, and modulate, badly; parts of the supply circuit ring with very high frequency rubbish. This is why amplifiers like Krell get such a reputation - monster transformers, etc, get around this issue to a good degree; the alternative is to have self powered subwoofer, or similar - transfer the problem to electronics that only worry about the bass region.

 

I've done much playing with Spice modelling real power supplies handling typical mains, with realistic power supply parts, feeding an amplifier handling big bass frequencies - the voltage rapidly collapses, and can cause the amplifier to clip, it runs out of headroom.

[cjf]

On 7/16/2017 at 4:16 PM, gmgraves said:

That's what I have. It's a big medical equipment transformer, weighs about 60 pounds (27 Kilos). Each huge end bell contains oil-filled capacitors. The secondary side end bell has a medical-grade mains receptacle on it with two plugs. NOTHING other than 60 Hz 120 Volt AC mains gets through it. The primary, viewed with an o'scope might look nasty, with all kinds of switching spikes, and line noise riding on it, but the secondary is as clean as a new penny. No spikes, no switching noise, no line noise, just a pure 60 Hz sine wave. And yes, you can hear the difference! Expensive line cords as big as a newborn baby's leg and costing thousands of dollars might be mouse milk, but believe me a big medical grade isolation transformer is for real! I bought mine, after looking longingly at it for years in a surplus electronics shop. When said shop was going out of business, I paid them one last visit. They had a US$175 price tag on it which is why it never sold in all those years. The last time I was in the shop, there was a big sign over the counter: "Everything must go - no reasonable offer refused!" I went back, picked up the transformer and plopped it on the counter. "Fifty Bucks!", I said. "Sixty", said the proprietor. "Done!" said I, pulling out my wallet. Best $60 I've ever spent (on audio, that is!). 

Do you happen to have any measurements that you've done yourself your willing to share with the peanut gallery on this miracle $60 "Medical Grade" ISO Transformer?

 

Given all the mention of one only needing a properly built amplifier to begin with to avoid the need for such a power cleansing contraption we may be inclined to think your feeling the need to own one yourself is an admission of guilt that your own amp must not be properly designed like the rest of us poor slobs.

 

Do you really think this $60 ISO Transformer is as good as you think it is easily outclassing everything else on the market regardless of how much research,time and money was blown during the creation of its more established competitors products?

 

Please pass me whatever your smoking, I need to experience the same high

[AudioDoctor]

I have a few Shunyata products.  A few days ago in a big storm my home was hit by lightning.  Not a single thing connected to them was damaged.

 

Take from that what you will.  I do think they increase sound quality too, for a few reasons.  1 being common ground, and 2 being, isolation of computer noise from audio gear.

[jabbr]

1 hour ago, cjf said:

Do you happen to have any measurements that you've done yourself your willing to share with the peanut gallery on this miracle $60 "Medical Grade" ISO Transformer?

 

Use of isolation transformers is very well established. This has nothing to do with "instantaneous current delivery" rather reduction in leakage current (among the other things). Generally the interwinding capacitance is specified by e.g. Topaz. Mine have 0.0005 pF  giving common mode noise attenuation > 100 dB =>

https://books.google.com/books?id=OtXLBQAAQBAJ&pg=PA217&lpg=PA217&dq=0.0005+pf+capacitance+transformer&source=bl&ots=wf6fxXGSYf&sig=Vnm-U1csYZOIbOkd-OkuMjXrqxI&hl=en&sa=X&ved=0ahUKEwj45Mjl7ZvVAhUEZCYKHQrYAfIQ6AEIJDAB#v=onepage&q=0.0005 pf capacitance transformer&f=false

https://coefs.uncc.edu/mnoras/files/2013/03/Transformer-and-Inductor-Design-Handbook_Chapter_17.pdf

 

[Speedskater]

The 60 pounds refers to the weight of the transformer (that's about 27 kilograms) not the price.

Transformers similar to this are standard good-engineering-practice in industrial R&D labs.

While I haven't checked, the new price may be well over $1000 US.

[jabbr]

14 hours ago, fas42 said:

The amount of energy needed to drive speakers with music having heavy bass content overwhelms the ability of the mains-transformer-smoothing caps to maintain delivery - the voltage rails sag, and modulate, badly; parts of the supply circuit ring with very high frequency rubbish.

This would be readily apparent in THD measurements. If your SPICE model shows "high frequency rubbish" then you probably need better snubbers. DIYAudio has endless discussions on amplifier design and a subforum on power supply design -- if you post your SPICE model there folks would help you out.

[jabbr]

11 hours ago, Speedskater said:

While I haven't checked, the new price may be well over $1000 US.

Yeah I'd like to reiterate that @gmgraves score of a 60lb trf for $60 is a great deal --- anything under $2/lb is --- that's used surplus of course  --- I have a too large collection of the 0.0005 pF Topaz that I've been acquiring on eBay -- you need to look for low shipping prices also. There's a guy in Indiana who's been slowly unloading some.  My wife is mystified as to why these superheavy boxes keep arriving from Indiana. These industrial isolation units can be wired balanced and/or floating but you need to know exactly what you are doing to avoid danger.

If you'd like a premade ready to go unit I highly recommend the Equi-tech "Q" also very very heavy but waay more than $60  

[jabbr]

20 hours ago, kennyb123 said:

Are you telling me that if I intentionally place a high impedance and highly reactive load between the amp's power supply and the wall outlet - this won't impact in any way the amp's ability to draw current quickly?

It might not -- typically there are many miles/km & many Trf between power plant and your amp. By   Thevenin's Theorem:  adding or removing a slight impedance at the end of a long chain has minimal if any effect. The way to actually reduce output impedance is, once convert to DC add low ESR output capacitance -- one can also use active measures such as high bandwidth capacitance multipliers.