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

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

I must be one a roll.

@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 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.

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,

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.

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.

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.

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

I’m going to go ahead and cautiously hazard that invoking the works of Kafka in this context is a bit, um… ambitious? 

I would agree on general principle @rfnoise.

At least by providing the list of the 13 reasons is appearing like more than Kafka got during his trial.
And Kafka was the one trail “without reason”, whereas what we have here is a trail, but no actual dependent having been nominated.

So maybe it’s just forward thinking to come up with the arguments against the naysayer(s), before they had even appeared in the thread?

I am sure that there are a few people somewhere in the middle, that want to know if the devices work, and when they are needed… Rather than reading vilifications against people who discount the devices who are not yet even present. It seems like it sets a bad tone for dialogue to start out with an attack using the baker’s dozen.

• How are we to know when to use a device?
• How are we to know which style of device to use?
• How are the devices designed to work?
  • Noise suppression
  • Voltage stability / reshaping
  • Under/over voltage protection
  • etc
• How does one know when they do not need such a device?

I assume that I do not need one because I have a lack of any noise/hiss etc when it is on, but not playing any music.

And when it is playing simple sounds it is clear and sounds pretty good.
Or is there more to it?
And if so what is it?

@nonoise Agreed. Are you ready for none of them to answer my two questions? They won’t, I predict. (Bracing for powerful challenge in 3...2...1...)

Queue the response, 1…2…3…<and>…4

People who say it’s all snake oil raise two questions for me:

1. Do you think that these cords and conditioners have just been fooling everyone for decades? And they are too stupid to realize it and too deluded to know that they are not hearing a difference? If your answer is "yes" then you have a very low opinion of thousands of audiophiles.

2. Have you tried it? And if you had and it made no difference *to you* are you then just willing to extrapolate from one example to everyone else who does hear a difference?

People spruicking power conditioners have the onus on them to show that their product does something.

It is not intellectually appropriate to do a Greco Roman reversal, set up a Kafka’esque trail for the non-believers to offer some testimonial based counter point against the largely testimonial group that likes the power conditioners.

For one it is hard to disprove/prove a negative.

The ifi, for instance, shows the wall noise decreasing with one of their units.

How hard is it to show that some product works as described?

Everybody wants to sell more stuff. But if a power conditioner comes with a 14 gauge cord on it, then I would suggest passing, it isn’t designed to provide power for the spikes. The exception would be if a power conditioner has provisions to store power internally to address the spikes. Need to makes sure impedance doesn’t limit the ability to address fast spikes.

Note to future self @holmz
“When you make a product, then use a large cable, so it looks like it should really work.”

 

Naysayers’ reasons include:

1) they don’t know what they don’t know

2) they think they know more than they know

3) arrogance

4) ignorance

5) savior complex

6) fear - that their structured world will come crashing down if they’re wrong

7) poor hearing

8) low resolution audio system

9) old guy ’get off my lawn’ stubbornness

10) learning something new requires curiosity and humility

11) they don’t really understand what ’noise’ and/or ’black background’ is

12) they think that proper wire gauge is a panacea

13) ?

^This broad ad hominem attack^ is really nice. It shotguns out wide, and points out all the possible flaws that one can have. Plus it stays emotional, which is more powerful than facts.

It is so encompassing that it also hit the OP, so he is either (pick 1-13) , or needs the gear to be in the “in crowd”.

At least a few people just want to have a factual way to know if something will work before buying it. And I assume that the OP may be somewhat in that group.

But instead of offering any reason or fact, y’all convert it into a circling of the wagons against a naysayer attack, before the attack even began. It is pretty intellectually shameful, but it is great psychology to get everyone in locked step and the coherent message out early.

 

@holmz "I assume that I do not need one because I have a lack of any noise/hiss etc when it is on, but not playing any music."

Thank you Holmz, brilliant point, assuming you run it loud.

I do when I am assessing whether or not there is a noise issue.

You are quite lucky if you hear nothing at all at top volume setting. My system and most others has a little low level white noise at that level. One can measure how far down it is. And test if a $1500 power cord removes or reduces it. It won’t, so try a $15,000 cord. A mains conditioner might …

…

I have had some issues in the past.

• I recall once a slight ground hum that was cleared up with rerouting wiring and star grounds.
• I had a bad hum on the that was the result of the lighting circuit in the ceiling above that room
  • But only affecting the TT
• Most of my gear is still on a 230–>115v transformer, so maybe that acts like a choke to limit noise or harmonics?

Or is my current preamp or amp just an odd ball low noise case?

It does make a hum on the TT input, with that starting at about 2-3 o’clock on volume (6:30 to 5:30 is the total swing of the volume… so starting ~ 3/4.)

I usually never run it past ~1 o’clock as that is about 95 dB(A) in the slow setting… depending on the music.

However on other inputs there is no hiss even at max volume.
This is with the head down in front of the left speaker.

The inside SPL is ~40-45 dB(A) with the front door shut, and the refrigerator running in the other room is the majority of the humming background sound.

With the front door open is 52 dB and the with the AC on is ~55dB ambient SPL background noise level.

I can hear the buzzing of the outside insects n such. But relatively quiet.

It‘s not a question of removing audible hum hiss and noise. I have no such issues yet have garnered definite audible improvements with the use of a PS Audio P10 and an industrial 1KW isolation transformer (used individually) upstream on certain system components.

• Which “industrial 1KW isolation transformer”
• Which “certain system components”

... I really didn’t sign on to audio Gon tonight looking for a beef. I guess some of you guys are hearing something, I tried to hear it and spent a bunch of money in the process and nothing...

Money that may have been better spent on things that do make a difference

My answer is yes to your first question, but your own conclusion is incorrect. It doesn’t require a detailed knowledge of logical and/or formal fallacies to understand why that may be so.

…

People often will spend a few hundred or more on questionable things, and do it multiple times. And often not spend teh same total amount in a single “upgrade”.
Hope rings eternal.

@atmasphere do you have experience with your amps benefiting from using the two example of power conditioning units that you mentioned?

Basic physics. Everytime you double the size of a conductor, you reduce the resistance of the conductor by half. Output impedance is the product of LCR. Reducing any aspect of the impedance allows the available current to increase (the current well). Instantaneous power demands in audio are not often spoken about. Take the Telarc recording of the 1812 Overture as an example. Someone smarter than me did the calculations on the reproduction of the cannon shots in that recording. To accurately reproduce that event considering the average listening level of 2 watts would require 10,000 watts of instantaneous power.

The capacitors only get filled up when they are at or below the voltage coming out of the transformer-rectifier-regulator. That physically is happening in a rectified sine wave that operating at 120 Hz. So there is a great deal of time (maybe a 1/4 of the time), where the AC is NOT feeding the capacitors any DC.

The power supply in an amplifier is holding DC and buffering the AC to provide that energy reserve..

This is pretty much analogous to how a toilet works. The thing flushes very quickly, but takes many seconds to fill the bowl. The pressure and size of the pipes coming into the house do not go directly into the flushing… they merely keep the bowl filled for subsequent flushes, thereby buffering the demand for water.

The power distribution cable from the transformer to the entry service is #2 wire.

For the entire house… running an electric oven, AC, etc. It is not for a single (0r pair) of MB amps that draw 900W (~9A) each.

It just makes sense, logically and mathematically, to supply a dynamic system with huge instantaneous current demands as much current as possible.

Do the lights in the house flicker whenever the bass drum hits?
If not, then the amp is not pulling that output power directly from the input AC.

It is buffering the energy in the capacitors.

A Class A PASS XS300 monoblock will dump 48A on demand.

How do we arrive at 48A? Are you using 8 ohm speakers? Or what is their impedance?
300W at 8 ohms implies “rails” at ~50V, and at 8 ohms that is about 6 amperes.
(Driving a 1 ohm load can get us to 48A - so I guess you have 1 ohm speakers?)

In any case that amp is a device providing voltage amplification and impedance matching. It is not forcing 48A into the speaker, it is only providing up to 50V. The speakers get whatever ohms law translates into in terms of current.

You need two of these. See where this is going?

Not exactly… no.

 

Holmz, there is no future in trying to have a cogent discussion with a person that misses 90% of the conversation to dwell on 10%. You are obviously so much smarter than I am.

How do you arrive at concluding that I am smarter than you?
I am just trying to understand here, and make sense of the physics.

What is wrong with me only needing further explanation of 10%?
Maybe I got the other 90%

Let’s take your analogy to the opposite side of your argument. 900W represents 7.8A @ 120VAC. 24AWG wire has a current rating of 8A. Are you willing to use 24AWG on the Xs300?

No!
would probably use whatever cable Nelson provided, or I would ask him.

Ask yourself why Nelson would use a Neutrik powerCON rated for 32A @ 250VAC.

The output of the amp needs to be larger speaker cable because the voltage is lower and there the current is higher for the same wattage.

The PowerCon is a great connector. I think that they only come in 32A, and that covers most all professional needs. Is that between the seperate power supply and the amp? Or is it from the wall to the amp? If it is “between” then it makes sense as the separate box is probably supplying 50V “rails”, so it needs be higher current capability than the 120v side is.

If one is using a 12 gauge wire for the speaker, then the incoming power, being at 120v, should not need to be bigger than 12 gauge (If we assume that the amp was 100% efficient). The amp is not 100%, but the 120v is a lot higher than a 50V rails so the current will be lower on the AC side.

The whole thing about 2 gauge coming to the house, is to cover things like ovens and dryers which need huge amounts of power/current.

a 1kW hair drier or 900W amp does not need 2 gauge.

 

@atmasphere

Thanks for that link. My next acquisition may have to be some high impedance speakers! But tell me, can we cheat and just add a resistor in the line to a lower impedance speaker and get the same enhancement of performance from the amp?

@piaudiol

^No.^

I think a better test would be to add the 4 ohm resistor on the incoming power plug cable between the amp and the wall.

• At 4 ohms and 120v that limits the incoming current to 30A.
• If we assume that the spec sheet about 900W draw is correct, then we have 8A of RMS current draw.
• At 8A the voltage drop with 4 ohms is 32v, so we go from 120 (which is like 170 at the peak) down to 88v (which is really 138).
• The effect is that we significantly cut down the angular time over which the capacitors can be filled.
• I would doubt it could be heard at anything below really loud levels, but it would be interesting to try it.

The impedance difference between a 10 gauge and a say a 18 gauge feeder cable is in the milli-ohms., 4 ohms is a wildly high value.

But it is a great test to go way beyond the scope of reality to see if there is a benefit in the theory of the input cable driving the speaker.

Note: 8A at 30v drop would be a 240w so it would need to be a large resistor, or a few 100W resistors in parallel… like maybe 4x 8 ohm ones to get to 2ohms.
And a fan cooling them would be great to have. 

Yes, but the resistor will work against you than for you. It will absorb power too- for example if a 4 Ohm resistor in series with a 4 Ohm speaker, the resistor will absorb about 1/2 the power! Its not practical, and the speaker will see a vastly reduced damping factor.

@bruce19 

And the 4+4 (system) will result in half the power at the same level that the sole speaker at 4 ohms would have gotten

So the speaker will get 1/4 of the power, and the resistor 1/4 of the power… and the 1/4+1/4 sums to halving the power.

It may be good to try for a listening test, and cranking in and extra 6 dB on the when comparing it. But we would have to see what you get.

Mr atmaspere,

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

Thanks

I suspect (guessing here), that he does.
But…

Solely Inside of the amplifier.

I’m a power supply guy and it occurred at a show in a discussion with Nelson, who is also a power supply guy.

But whatever the minimum impedance is for your speakers, then divide the 50V rail by that impedance… and whoo-la… we get the maximum amperage that the amp can deliver to YOUR speakers.

A theoretical (or real) 1 ohm load is the only way to get 48A.
It is quite possible that he designed it to be able to push a 1-ohm load, but that has little to with what it will actually provide in a specific use case.

I, too have read about that number in reviews...

Perhaps the reviewers could be repeating what others say, or what the specs say?

If they measured it, then it gets to be more towards facts, than being more like “lore”.

It would probably be more productive to reach out to Mr. Pass for clarification as to what it means, and what it means with a a specific speaker.
(I, and likely others, would be interested in what he says… I suspect that it means he has a monster of overkill in the power supply… which is great.)