Why do I need power management if I have a great power cord?


Isn't it kind of unnecessary to additionally add a power conditioner if I have an expensive audio file grade Power cord connected to a component?

So you buy a Power conditioner from a hi-fi store and they say oh, you need a really good power cord to go with that and then another one to go from conditioner to the component. Do you need it all and why? Seems the last couple of feet before the component should be more than enough.

jumia

Would love to see your system, or know what’s in it. Do you use power management in anyway?

I don’t (but have a number of customers that do). My preamp employs heavy power supply regulation, which helps out immensely, and my amps employ over 35dB of feedback and are able to reject power supply noise and also employs regulated power supplies. Both also have built-in DC blockers. Equipment that lacks that sort of feedback and/or regulation needs all the help it can get.

I did rewire the audio room AC wiring, complete with Hubble AC outlets.

I’m a power supply guy and it occurred at a show in a discussion with Nelson, who is also a power supply guy.  I, too have read about that number in reviews...

OK. What is far more likely is that the 48 Amp value is actually how much current is present when the power supply of the amp is shorted. Its available to the output section in the form of charged capacitance. This is used to help reduce IMD in the output section and is not something that the output section can pass to the loudspeaker (if you see what I did there 😁).

You don't need any of it, just a complete waste of money that enriches audio dealers. 

To atmasphere: I’m puzzled by your comment that this Nelson Pass quoted 48 Amps is “how much current is present when the power supply of the amp is shorted. It’s available to the output section in the form of charged capacitance. This is used to help reduce IMD in the output section and is not something that the output section can pass to the loudspeaker.” Perhaps I failed to see what you did there; but I thought that the extended time that my tube amp can drive my speakers from the source when I turn the tube amp off (while the source is still playing) was, in fact, the capacitors discharging through the speakers. At least that was a comment I remember John Atkinson making in a Stereophile review of a tube amp that I read online. Other contributors to this forum also seem to assume that the capacitor banks are there to help the amplifier deliver transients to the speakers outside the range of their normal current demands. I’m not (yet) experienced in building amplifiers, but I am intensely interested in understanding how they work. If, as you say, the speakers are in series with the amp’s output terminals, and I never considered them that way before, but I guess they are, then they would definitely need current to drive them. Of course, your linked discussion clarifies their rather intimate relationship (you can’t have one without the other [current without voltage] if power is being produced or consumed). Further, the ‘transients’ at lower frequency, i. e., the ‘attack’ of a bass drum strike would require more power than a ‘transient’ of a high-hat cymbal strike because its relative duration would be longer. Just thinking out loud, here.

On second thought, if ‘what you were doing there,’ is saying that if the power supply is being shorted to produce 48 Amps; there isn’t going to be anything near 48 amps at the output terminals —at the same moment in time; then I totally get ‘what you did there’ —you made a joke, which this discussion sorely needs. 👍

 

Alternatively, if you are saying that 48 Amps cannot be used both for Intermodulation distortion AND output at the speaker terminals, then I accept that as well, as current can only be ‘consumed’ once in any circuit, I suppose.

I must be really really stupid not to understand much of these past several posts. I would hope the people commenting in such a technically proficient way would recognize that most readers have no clue what they’re saying.

There in lies a huge challenge, very very technical issues confounded buy those who don’t explain themselves very well. Very unfortunate as what they say is of value but lacks clarity.

They exhibit tremendous effort to achieve improved Sonic Quality I hope, and yet it has limited value to me because I am really really stupid I guess.

The marketing of these products can be horrible as the manufacturers don’t really do much to improve an understanding of technical information. Most dealers don’t understand all this. There have been noted exceptions along the way but still it is not explained very well.

I just installed a dedicated circuit for my system.  I installed 10 awg solid copper.  Although 10 awg supports up to 30amp, I used a 20amp breaker.  More than I need.  I also installed a 240V circuit.  I needed it since I bought a European amp that only uses 240V.  But I'm glad to have it for any future amps as doubling the voltage cuts the current in half for the same power.  This makes your amp feel like it is just sitting next to the power plant with a huge cord.  I too highly recommend running your amp at 240volts instead of 120 if possible.

To install 240V circuit the marginal cost increase compared to the 120V circuit is not much.  An extra breaker (perhaps $10) and 3 conductor vs 2 conductor wire, and then a slightly more expensive outlet.  the main cost of the circuit is all the labor and work inside the wall and cutting wallboard and replacing it.  All of that doesn't change when you install the 240V circuit with your 120V circuit.

Doubling the diameter of a wire increases cross sectional area, and approximate power carrying capability, 4 times, not 2.

The power delivered to the speaker is almost irrelevant to the power the amp needs, especially for class A.  Not sure why that discussion broke out.  My class A 35 WPC amp, that I run at about 1 wpc 99% of the time, uses 400 wpc, either at idle or at max volume.

I reference people back to page one to the post I made with a quote from the AR user manual where Audio Research requires a 20 amp, 12 awg circuit for a 75 wpc class AB tube amp.  I know many of you don't believe it can be true unless you hear it from an OEM so it is there in black and white.  I copied and pasted it.

Jerry

I have yet to hear a conditioner that didnt take away as much as it gave. Far better to start with dedicated lines properly done and then experiment.

U think you are right...

By definition electronic engineering is about trade-off craftmanship...

In some case a conditioner is postive addition in some other case negative... And with the same gear it can also change in time if we change other factors in mechanical, electrical and acoustical working dimensions...

I have yet to hear a conditioner that didnt take away as much as it gave. Far better to start with dedicated lines properly done and then experiment.

@rtorchia

Your system? It would be good if put photos of your system on line under your user ID. Your experience? What components and power components have you tested?

Other contributors to this forum also seem to assume that the capacitor banks are there to help the amplifier deliver transients to the speakers outside the range of their normal current demands. 

  1. Capacitors are the are the only source of power to the speaker. It is not the power cable coming in. It is the capacitors via the tube or FET or whatever output valve that draws from the well which is the capacitor.
  2. There are no transcients outside of the normal current demands. All are inside “normality”… if the amp is not clipping.
  3. A speaker is not a shorted amp… that is what he did there.
    1. If fact shorting an amp will often fry an amp,

I bought a PS Audio Stellar mainly to protect my 50k+ electronics from damage. But i heard zero difference in sound quality. We must hear out all the expert opinions but be guided by our own experience. I think my system sounds amazing, with or without the PSA unit. I dont mind a $2500 outlay for the protection it provides. But we should all get off this crazy wagon and just buy records to support our favorite artists. 

I must be really really stupid not to understand much of these past several posts. I would hope the people commenting in such a technically proficient way would recognize that most readers have no clue what they’re saying.

They don't either.

OK. What is far more likely is that the 48 Amp value is actually how much current is present when the power supply of the amp is shorted. Its available to the output section in the form of charged capacitance. This is used to help reduce IMD in the output section and is not something that the output section can pass to the loudspeaker (if you see what I did there 😁).

Yup, caught that. Shorted or driving Acoustats 😁 Talk about a vicious load for an amp. They were the reason for Ampzillas and Crown DC300 amps! The DC 300 would drive a cast iron pipe or a welder! 🤣

Yup, caught that. Shorted or driving Acoustats 😁 Talk about a vicious load for an amp. They were the reason for Ampzillas and Crown DC300 amps! The DC 300 would drive a cast iron pipe or a welder! 🤣

I have a 300A welder.
However I do not use it for speakers.

And I would not consider a Pass amp for use as a welder, but it might be cheaper than some welding machines.

I just went from one to two subs and my wonderful monitor speakers along with an integrated upgrade. Just a couple of days a gi I realize I’m not getting any change in bass response and while my monitors sound great my home concert hall was lacking. Sure enough both sub fuses blew, yes power surge( Florida go figure) I had upgraded my wall outlets and power cord but simply forget to plug into my McIntosh power conditioner.  My one piece of Mc gear left. Simply over looked and now back to glorious sound. Yes that was an expensive piece but it will stay put

How much did the fuses cost?
Are ythe subs working with the new fuses installed?

To Holmz: Thank you for the clarification regarding ‘what he did there.’ I lost sight of the fact that the amp’s input signal is used to modulate the power supply being output to the speakers via tube or transistor.

After digesting the Audio Science Review vs. PS Audio ‘debate,’ I’m no longer considering the purchase of a power conditioner for the purpose of cleaning up my sound, but I am going to look into a decent, audio-grade power strip to protect my equipment, as recommended by Amir at ASR and by a link posted earlier in this thread.

To the original poster: My take-away from the discussion thus far is that you don’t need a power conditioner, but you do need to be confident that your equipment is getting the power it needs. A dedicated line from the fuse box would be best, but short of that, try to keep computers, WI-FI routers, dish-washers, air conditioners, washing machines and the like off line if they are on the same circuit. (Hopefully, they aren’t.) You probably need to invest in a ‘better’ quality surge protector. The jury is out for me regarding the use of isolating transformers, unless you are experiencing issues with ground hums (and I hope you’re not).

I’m not convinced of the need for 240 volt service, personally, but I might consider it as an alternative to pulling 10 AWG solid conductor wire. I would think that 12 AWG would be plenty at that voltage. 

For me, I have tried different interconnects, speaker cables, power cords, power conditioners. Each has sounded different, for better or worse. So anyone who doesn't hear any change either has a low fidelity system, or insensitive ears. 

 

But late last year, I purchased a stand alone surge protector from Zero Surge, a company that makes OEM for other manufacturers. I discovered that running my integrated amp through it reduced the dynamics. I called ZS and spoke to a guy named Jim (if I got the name correctly). I told him what I heard, including that I had done an A/B/A listening test. 

 

He told me he has a degree in physics and that what I heard was impossible. "It's just wire", he said.  I told him that there was no mistake in the difference between plugging into the ZS and plugging into the wall. I responded that if what he knew didn't explain the sound difference, then there's something he is not aware of in the product's design.

For me, I have tried different interconnects, speaker cables, power cords, power conditioners. Each has sounded different, for better or worse. So anyone who doesn’t hear any change either has a low fidelity system, or insensitive ears.

We can have opinions about interconnects and speaker cables.
However…
It is exactly opposite wth power cords and power conditioners.

The higher fidelity systems usually have the better power supplies in them and are more immune to what power is coming in. That is part of what makes them higher fidelity, but it also is a sign that they are not cutting corners in one area, and likely also not cutting corners in others.

I would believe that on some lesser quality systems, that these snake oil things might work, but they should work less (If even at all) on systems that are designed right.

We can paint the Camry red, but it only identifies as a Ferrari, it doesn’t actually become one… much the same as a fancy cord does not fix an inadequate power supply design.

You are right about power cords and power conditioners, and i concur with your metaphor about painting red a Camry to pass it for a Ferrari... 😁😊

But when these common sense and common place facts are said and well said by you, there is other alleged "snake oil"devices which cannot be put under the rug and be treated as useless because the owner of the costly price tag of some higher end audio system decide that it is the case...

These are the electrical various possible control over the part of the gear and of the room/house electrical grid but also the mechanical vibrations/resonance controls but also the more important acoustical passive treatment and especially the mechanical acoustical control devices...

These are not ALL snake oil creations ...

This is where a low cost system can exceed in S.Q. or rival not far behind it some costlier one, it is here where your Ferrari metaphor ALONE did not work anymore...

Audio experience does not result DIRECTLY from the gear system coming from the store heaven but audio experience result also from the gear system IN A SPECIFIC acoustically controlled or not controlled room...

That is the limit of this popular Ferrari metaphor....It takes a DESIGNED RACE TRACK for the Ferrari to perform , put a Ferrari in a sahara desert caravan track it will not work well...In my metaphor the acoustic control of the room is the DESIGNED track and specifically for it, where the Ferrari perform... Any system without acoustic control is like a car in the deep sand track of the desert ...It did not work well....

Then all acoustic devices are not snake oil or secondary artefact we add or not to a system, they are fundamental like the designed track for the Ferrari...

In my set of acoustic controls devices i use classical Helmoltz method and devices yes , but also unorthodox devices to help my low cost system to not be so far away from SOME highly costlier one... None of them are snake oil...

Yes my system is NOT high-end at all , but yes my ratio quality/price is very high and my experience is not so far AWAY behind system costing 100 more when these system are put in an uncontrolled  room in particular... Thanks to Helmholtz among others...

Acoustic is the key not the price tag....

And all added devices around a system are not ALL snake oil....

Exemple out of acoustic field : tuned mechanical vibration control devices....They are ESSENTIAL....

 

 

For me, I have tried different interconnects, speaker cables, power cords, power conditioners. Each has sounded different, for better or worse. So anyone who doesn’t hear any change either has a low fidelity system, or insensitive ears.

We can have opinions about interconnects and speaker cables.
However…
It is exactly opposite wth power cords and power conditioners.

The higher fidelity systems usually have the better power supplies in them and are more immune to what power is coming in. That is part of what makes them higher fidelity, but it also is a sign that they are not cutting corners in one area, and likely also not cutting corners in others.

I would believe that on some lesser quality systems, that these snake oil things might work, but they should work less (If even at all) on systems that are designed right.

We can paint the Camry red, but it only identifies as a Ferrari, it doesn’t actually become one… much the same as a fancy cord does not fix an inadequate power supply design.

@mahgister I was just opining on the topic of ”Why do I need power management if I have a great power cord?”

I am not saying that we need, or do not need, Helmholz resonators if we have a power cord.
Nor that we need, do not need, a power cord if we have a Helmholz resonator.

And not anything about Helmholz or Shuman resonators or pyramid shaped devices.


The main/only that I am saying is that the power cord delivers eneryy to the amps power supply, and that quality amplifiers usually are largely immune to what is happening on the city side of the chassis.

Perhaps some low quality amps would benefit a power conditioner or a power cable. But I try not to use those amps, and I don’t prefer to spend money on cords and conditioners if one could use that money on better amps.

 

These are not ALL snake oil creations ...

I have seen the nice looking “boxes of dirt” grounding systems. Those seem like snake oil.

The Helmholz resonators have a theory.

The other copper disks and pyramid shaped jobs, I will not comment on.

I apologize then but i reacted also to the word "snake oil" in your post...

I apologize because sometimes i react too much to some words..."snake oil" for example associated to pyramidal objects ... 😉

I was ok with your post about power cord and power supply , i think the same as you, but the comparison of a costly audio system with a Ferrari is a comparison which had some limit if not completed and a comparison which ask to some addition to be accurate... A gear system so luxury and high tech it is cannot sound at his potential peak in any room no more than a Ferrari on any track will perform the same...

I did it....

 

The other copper disks and pyramid shaped jobs, I will not comment on.

These devices you see are SECONDARY now for me.... They work but their effect is small compared to my others created devices in acoustic in the last 2 years...

The photo you see in my virtual page is many years ago already.... None of my main acoustic grids of devices are there ...

Why ?

Because i dont want to be ridiculed by people ignorant of acoustic when they will se straws, cardboard empty paper rolls and plumber discraded tunes etc...

And anyway it is not esthetical ....

My dedicated acoustic room was my research room so ti speak.... It is now finished...

My point in my audiophile journey was the creation of an audiophile experience at no cost or very low one... I succeed....It is not necessary to believe me... All my homemade  devices are not equal in degree of improvement for sure but they cost peanuts...The more powerful without doubts  are the acoustic devices...

My discovery that for example acoustic control exceed in power " most"  gear upgrade is a measurable objective  fact easy to verify and which is known by all acoustician......The room is if not the ONLY the MAIN luxury in audio...

😁😊

I apologize then but i react to the word "snake oil" in your post...

I apologize because sometimes i react  too much to some words..."snake oil" for example associated to pyramidal objects ... 😉

What I actually think cannot be proved by what I actually wrote.

The pyramid power has dated back a long time with claims of keeping food fresh, razors sharp, and other things. (I use a refrigerator and have a beard.)

I do not personally use those pyramids, but it’s possible that I have a Bangles LP… I should do, as I like the gendre.

There is also a huge difference between making ones own resonators and foil covered pyramids, and selling magical boxes of dirt and other things at obscene prices.
No one would buy the pyramids at $1, but at $1000 it is more likely that a queue might start forming.

By the way the pyramidal shape of the device in my photo is a red herring for some who judge easily , i also used other forms because the form is of no importance here, the device is made by 2 materials : shungite +copper tape... The essential fact is the specific minerals here and his mass... But some shungite dealer send me pyramids and i bought them because they were cheaper ...I also have spherical one, plate one cubical one , the form does not matter save for easier placement...I used them all along my electrical grid...It is only one of my experiments...

Then this "pyramidal" shape is not my "tin foil" hat... 😁😊 And i cannot sell 1 dollar of shungite material to someone else 1000 thousand bucks...By the way....

i sell creativity not "snake oil" ...

I do not personally use those pyramids, but it’s possible that I have a Bangles LP… I should do, as I like the gendre.

There is also a huge difference between making ones own resonators and foil covered pyramids, and selling magical boxes of dirt and other things at obscene prices.
No one would buy the pyramids at $1, but at $1000 it is more likely that a queue might start forming.

Here you are more right than with your Ferrari metaphor...

Most people indeed laugh at my 1 dollars homemade devices, pyramids or not... they will not laugh so much for sure if they were costly and esthetical... You are right about that...

I laugh the last though... 😁😊

I dont bought  tweaks nor upgrade...

I dont need to....

Some experiments and some knowledge could spare big money....And yes my car will never be transformed in a Ferrari but it roll on the same designed track very well and perform at his best there not so far away than some can think behind the Ferrari .... After all my gear (car) was well chosen... 😊

And i am not jealous of all those who put their Ferrari on ordinary undesigned road anyway...An ordinary car can beat a Ferrari in the desert...

 

My deepest respect to you for your patience... And my best....

No one would buy the pyramids at $1, but at $1000 it is more likely that a queue might start forming.

Here you are more right than with your Ferrari metaphor...

I must be one a roll.

No by any chance, but sometimes some metaphor are more deep and simple and more useful than some other...

There is more evident truth or more evident direct similarity about the lenght of a waiting queue and an the alleged value prize justifying it and the waiting time at the end, than comparing an audio system to a Ferrari but forgetting about the designed track under the wheels...

For sure you know all that and yes i speak too much...

My deepest respect for your kind humor...And patience ....

😁😊

I must be one a roll.

I had another typo

It should leave been:
“I must be on a roll.”

But “I must be one, a troll.” Is at least english; whereas,  “I must be one a roll.” Reads as nonsense.

i already "partially"catch it...If you roll my post and read it  without trolling it ... 

😉

 

my deepest respect....

 

To atmasphere: I’m puzzled by your comment that this Nelson Pass quoted 48 Amps is “how much current is present when the power supply of the amp is shorted. It’s available to the output section in the form of charged capacitance. This is used to help reduce IMD in the output section and is not something that the output section can pass to the loudspeaker.” Perhaps I failed to see what you did there; but I thought that the extended time that my tube amp can drive my speakers from the source when I turn the tube amp off (while the source is still playing) was, in fact, the capacitors discharging through the speakers.

I thought it was funny to use the word 'pass' when talking about a Pass Labs amp...

At any rate, all that extra capacitance used in so many amps is there to reduce IMD at high volumes (so the amp will sound smoother). The amp isn't going to be able to make any more power since the voltage in the power supply plays a direct role in that- to make more current you'll need more voltage. All the excess capacity does is prevent the voltage from sagging over a short period of time when the amp is making higher amounts of power.

Many solid state amps have response to DC. This means that the low frequency timing constants in the amplifier go lower than that of the power supply (unless its a battery)- thus low frequency noise can cause the amplifier to modulate its power supply. When this happens, IMD increases. This can be avoided by having enough feedback in the amplifier circuit, allowing it to reject power supply noise, but that amount of feedback is a rather large value (+35dB), outside the reach of most current (and certainly vintage) amplifier designs. So for amps having lower amounts of feedback (or none at all) excess capacitance is used.

Because that current rating is actually a rating of how much current will flow if the power supply were to be shorted out (IOW nothing to do with the actual full power of the amp) you wind up with some advertised claims of 'current' which are pretty outrageous. The article I linked from a prior post explains in simple math how outrageous those claims would be if they were meant to be the actual current the amplifier is able to make into a speaker load!

Post removed 

Here is the latest video from Amir on power cords.

This statement is false. Amirm is testing a particular cable- an Audioquest, not all power cords. It would be correct to say 'Here is the latest video from Amir on an Audiquest power cord'.

However, there is a flaw in his testing regime, which is that all power cords obey Ohm's Law; the conditions he set up for testing did not have a great power draw on the cable. As a result, negligible voltage drop across the cord and quite naturally: negligible results.

The benefit of a good power cord IOW has to do with the current drawn through the cord which won't happen with lower powered equipment (for example, an Audio Precision tester).

Power cords that can make a difference don't have to be expensive however! I agree with Amirm that $5,000 should only be spent if it makes you feel better somehow... IMO/IME there's not much use in messing with power cords unless you have equipment that draws enough power to result in a substantial voltage drop across the cord.

I've seen a power cord result in a loss of 40 Watts at full power from one of our amps (the MA-1). That's a pretty measurable result! But the MA-1 draws a bit of power, being a 140 Watt class A triode amplifier.

Put another way, if you want to get the most out of some amplifiers a power cord can really help, and with other amps maybe not at all. The power that the amp draws from the wall plays an enormous role in this which cannot be ignored as we see Amirm doing in this video.

 

I have a 300A welder(like it).
However I do not use it for speakers.

And I would not consider a Pass amp for use as a welder, but it might be cheaper than some welding machines.

Can you recommend to me some cheap options? As far as I know, most of them are unsuitable for thin metal and cables

All the best! 

 

 

Clearly the ultra high endcables are a scam.

There has been little herein to justify spending so much money on a power cord.

The lower end Power cords being well shielded, better connectors, and focus on impedance are likely of value. Buy lower end I mean spending $500 or so.

It’s not rocket science