Dedicated powerlines, how many?

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microstrip

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In your opinion.

Almost nothing we do in this hobby is susceptible of provable, objective, peer-reviewable, factual analysis.

An electrician measured the in-rush current of my VTL at 30 amps. It does not make sense to me to plug that amplifier into a surge suppressor.

Ron,

Yes, but many thinks are susceptible of provable, objective, peer-reviewable, factual analysis.

Probably your electrician had a poor measuring instrument or the pod-mods of your VTL 750's were defective. The MB 750s have three separate power transformers that would create a large in-rush current. So VTL people added two levels of anti surge circuits - two parallel 10 ohm resistors that remain in series for the first seconds and then are shorted by a power relay, and until you completely turn the power label the primaries are in series, reducing the inrush current by a factor of 4.

It was one of the amplifiers with less in rush current I have owned - although it was high-power it could be used with power regenerators without triggering them down at start-up. I could even power them simultaneously!

BTW, in-rush current has nothing to deal with audio performance or sound quality. I post these comments just as technical facts about the MB750's. :D
 

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Yuri Korzunov

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Just a handful of parts. Now let's look at its measured noise spectrum:


Thank you, Amir. This picture give common point for discussion. All can see it absolutely identically.

I suppose difference noise floor may be defined by low measurement number. Probably after 20 … 100 measurements difference will lesser. May be deviation of network voltage give different noise.

I understand phrase «Surge suppressor» as «safe electricity» - protect apparatus against damaging by short voltage surges, but not against noise from electrical network.
 

Folsom

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The SurgeX has an intelligently done filter that's separate from the grey box. The grey box is what provides the surge protection, but there's a few other important parts not in it.

If people were only worried about the audio spectrum of noise then we can clearly throw out almost all engineering practices of every sort. Why bother with balanced cables ever? Just toss all your **** in the trash because it has lots of care to reduce noise from a huge range, mostly above the audible level. Why? Because the audible signal that is the music gets modified by noise within and out of the audible region. It's not hard to understand. But by all means have it custom made equipment with no noise control at all, have fun with bleeding ears, explosions, fire, etc...
 

Yuri Korzunov

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Noise may impact to signal as:

1. Adding.

2. Modulation (multiplication).

Case #1 impact to noise floor. As example, module #1 radiate in air and received in module #2. The radiation added to audio signal in module #2.
Performed reducing of noise, that received to signal path (cables, amplifier scheme), and radiated noise (shielding, ferrite rings).
Checked by spectrum at audio output of defended system/module.

Case #2 impact to signal with noise, that passed thru audio way into system/module, and generate additional harmonics. As example, it is modulation (noise) of power voltage.
Test tone given to input tested system give more chance to view the harmonics.
Harmonics of modulated noise may be visible as increasing of noise floor.
If power-voltage spectrum have only zero harmonic without noise (DC only) there is no modulation and no impact to audio signal.
Checked by spectrum at audio output of defended system and spectrum of internal power buses of modules.

Possible control via oscillogram: in case #1 in silent playback node, in case #2 in all modes. Because probable self-modulation due issues of power supple unit.

Resume: impact of any noise is visible at spectrums of audio output and voltage bus as noise with/without harmonics.

P.S. Balanced signal cables is way for noise decreasing in case #1.
 

amirm

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The SurgeX has an intelligently done filter that's separate from the grey box. The grey box is what provides the surge protection, but there's a few other important parts not in it.
Seems like there is a lot of confusion as to what is inside SurgeX. It is actually a pretty simple box (although more complicated than a typical surge protector). And its RFI/EMI filter that you call "intelligent," is not. It is a textbook (balanced) Pi Filter (see https://en.wikipedia.org/wiki/Capacitor-input_filter and countless other references). It is an effective filter and as a result it is routinely used also in DC power supplies inside your gear. Because those DC voltages are far lower than mains and are DC instead of AC, their design is far more effective.

Here is what is inside a SurgeX device:



Focusing on the EMI/RFI filter section, as we see it is just a handful of components. It would stretch imagination to think this is an unknown "intelligent" circuit to any electrical engineer let alone one designing high-end audio electronics doesn't know or understand.

Mind you, it is a heck of alot more than a chinese special $20 surge protector. So don't want to put it down in that regard. But the notion that it has some magic that designers don't know is so out of line.

The innovation from SurgeX is in the left two circles. Here is a better block diagram of what is there:



The AC mains hot line goes through two air coupled inductors in series and hence the term, "series surge protection." What is an inductor? A spool of wire wound together. Inductors don't like current to change so when the surge comes, it will attempt to absorb most of that surge. The block on the right is an active clamping circuit using SCRs and threshold detection to shunt the rest of the surge. The result is a circuit that does not wear out (like MOV based ones) and doesn't rely on ground wire to dump the surge into. More on this in the next post.

For now, if you are the type who has bought expensive AC mains cable, etc., insertion of this device means your AC current now travels through ordinary wiring in those two inductors. Depending on impedance of those inductors, there will be a voltage drop and some power lost. And the higher the current, the more that drop is. Hence the reason I am suggesting to not plug high power amps into it. Would something blow up if you did? No. But that and the introduction of another outlet and IEC input jack means you have a less robust path to deliver current to your load.

If you have a problem to fix and this device fixes it, then the above compromise may be merited. If you can't identify an issue to fix -- noise reduction is not one -- then don't just jump to put such device in the path of your AC mains.
 

amirm

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If people were only worried about the audio spectrum of noise then we can clearly throw out almost all engineering practices of every sort. Why bother with balanced cables ever? Just toss all your **** in the trash because it has lots of care to reduce noise from a huge range, mostly above the audible level. Why? Because the audible signal that is the music gets modified by noise within and out of the audible region. It's not hard to understand. But by all means have it custom made equipment with no noise control at all, have fun with bleeding ears, explosions, fire, etc...
Balanced cables are used to stop the ground currents that are multiples of 60 Hz from getting mixed with your audio signal. SurgeX cannot and will not filter those low frequencies. If such ground loops exist, they will continue to exist. Balanced interconnects are indeed the right and powerful solution to ground loops/currents. This is why we bother with balanced cables. It has nothing to do with EMI/RFI filter that operates at far higher frequencies.

As to music mixing with noise, it does. The issue is that you have not demonstrated that there are noise problems to solve with a mains high frequency AC filter. As I have explained and shown, the power that drives your electronics is DC and that DC power supply has filtering. Such noise can readily be measured. I have shown such measurements. You have not. You are relying on FUD (Fear, Uncertainty and Doubt) to sell your idea.

Do a simple exercise if inserting ultrasonic noise into your music and then tell me if you can hear it. You won't. You absolutely won't. The best proof of that is that there is a ton of high-res music downloads that have such components yet people are not aware of them at all.

Funny example of this is a friend asking me about these tones that are sold online for therapy. I took one of the files and analyzed it and found this:



The tones on the left are the ones supposedly providing therapeutic effect. But if you look at far right, you see this other pure tone whaling at 16.58 Khz. If you search for that, you find that it is the scan rate of an Apple computer monitor that was used to capture these files from analog to digital! Countless people have been listening to this high frequency tone without knowing it!

So come back with some data to back what you say. Anything really that shows what damage is done with high frequency interference and why our dearly paid for high-end audio gear is incapable of filtering them.

Finally we get to the Fear factor with reference to "fire." I assume you mean the standard marketing line of these devices saving you from lightning. Nothing is further from the truth. Lightning has incredible amount of power. We had one hit our home in Florida and it shocked my wife on the phone and it literally blew up the Romex electrical lighting wiring inside the walls! You really think that kind of power can be contained in that little transformer? That is like wearing a Hockey mask and standing in front of traffic while a truck hits you and think you can walk away! :D

Nothing will stop a lightning that hits close to your home. If however it hits farther out, then the best place to deal with it is at your meter or mains entrance. There, you can shunt that power into the (earth) ground. Indeed that is why that earth ground exists. It is to lower the let through voltage into your home by making the differential voltage smaller between the distribution point of power and your home. And there you better get an industrial rated one with very short cables.

A point of use device like what we are talking about is not about that.

Again, I want to say that SurgeX in that class of device is a cadillac. It is just that in the context of high fidelity sound or stopping a lightning, it doesn't make sense.
 

Yuri Korzunov

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Hi Amir.

Thank you for published information. What is point of measurement the spectrum (audio circuits, power lines into audio modules, other)?
 

amirm

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Hi Amir.

Thank you for published information. What is point of measurement the spectrum (audio circuits, power lines into audio modules, other)?
Hi Yuri. My pleasure.

On your question, the reason is that so much of what we know about psychoacoustics is in frequency domain. By converting time domain to frequency we can do a better analysis of audibility of things. This is why lossy music codecs like MP3, WMA, AAC, etc. all transform to frequency domain and perform their lossy conversion there and then transform back to time.

The exception is acoustics where time becomes important although frequency domain still plays a strong role.
 

MtnHam

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Hello,

as i moved to a new place which boasts a sever lack in available outlets i am forced to install new power lines for the audio system (a thought which i anyway considered also based on the various threads regarding dedicated power here and elsewhere).

My question is on suggestions/experience regarding the # of lines. As i run rather "lower" powered amps (7-20 Watts), could these be also fed from with the source/pre line to make it two lines (1 digital, one rest) or would you still go with a dedicated line for the power amps (thus 3 in total)?

Side consideration is the "power conditioner" (i use a Bybee) which then would not be available anymore for the power amps ( so either running w/o or need for an additional unit.

Thanks for your thoughts
antelion

It seems this thread has gotten way off topic! My answer to the OP's question is to run at least 3. You may not need them all today, but they could well be beneficial in the future. Once you hire an electrician to run the 1st one, the cost of 2 additional lines is negligible.
 

Yuri Korzunov

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Thank you for published information. What is point of measurement the spectrum (audio circuits, power lines into audio modules, other)?

On your question, the reason is that so much of what we know about psychoacoustics is in frequency domain. By converting time domain to frequency we can do a better analysis of audibility of things. This is why lossy music codecs like MP3, WMA, AAC, etc. all transform to frequency domain and perform their lossy conversion there and then transform back to time.

The exception is acoustics where time becomes important although frequency domain still plays a strong role.

Hi Amir.

Sorry for my English. I missed translation issues.

I meant "point" as "place into electrical scheme", not "point" as "sense".

AC > [amplifier or other internal DC bus] > [analog output of the amplifier ot other]

I know what is sense of measurements and I like what you show these things, because it give practical information about noise for certain equipment.
 

amirm

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Off topic?
OP specifically asked about power conditioners and that is what we are discussing:
Side consideration is the "power conditioner" (i use a Bybee) which then would not be available anymore for the power amps ( so either running w/o or need for an additional unit.

Thanks for your thoughts
antelion

Folsom has recommended a device and says its filtering is intelligently done. All engineers know about Pi filters so I am at a loss as to why he thinks it is intelligently done. What is the innovation he is pointing at?
 

amirm

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Hi Amir.

Sorry for my English. I missed translation issues.

I meant "point" as "place into electrical scheme", not "point" as "sense".

AC > [amplifier or other internal DC bus] > [analog output of the amplifier ot other]

I know what is sense of measurements and I like what you show these things, because it give practical information about noise for certain equipment.
I see :). The measurement I showed earlier was the output of a DC regulator as to show how it is able to be filtered there instead of doing so at AC terminal.

Measurements of analog output of the audio device would surely show no effect for these devices.
 

Yuri Korzunov

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I see :). The measurement I showed earlier was the output of a DC regulator as to show how it is able to be filtered there instead of doing so at AC terminal.

Measurements of analog output of the audio device would surely show no effect for these devices.

Thank you for expalnation! :)
 
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