Power conditioners?

Hi, all.

Does anyone have any experience using power conditioners, perhaps from Panamax or AudioQuest, with their active B&O gear?

Reviews of these products, for example, AudioQuest Niagara products, seem to be geared towards traditional passive speaker systems driven by large amplifiers. I run my BeoLab 17 and 18 through decent but run of-the-mill, not A/V-specific surge protectors for obvious reasons as my location is known for storms, power fluctuations and lots of interference in the power lines. So I imagine using an A/V-specific power conditioner with surge protection functionality would be wise. I just don’t seem to be able to find much information regarding using these products with active speakers, particularly those driven with efficient Class D amps such as ours. 

Has anyone noticed improvement in sound with use of these products? Or is their benefit primarily related to, and limited to, to surge protection? Or would anyone try to argue that even good surge protectors shouldn’t be used with modern B&O for some reason? 

Thanks! Cheers! 

Hi,

For Beolab 50 and 90, we specifically recommend that you do NOT use any filtering on the mains power. There is a discussion about this in the Technical Sound Guides for those loudspeakers.

(e.g. https://bang-olufsen.zendesk.com/hc/en-us/articles/360041571412-Beolab-90)

I'll ask our power people what their recommendation is for the 17 and 18 and get back to you here.

Cheers
-Geoff 

You’re the best, Geoff. Thank you!

Hi,

I have use Furman power conditioners/surge protectors since investing in a BV 7-40 in 2009. https://www.furmanpower.com/products/220-240-volt-region-home-theater-products

More for peace of mind than hoping to get any noticeable improvement in AV experience. No problems with their products.

Cheers,

Danny

I've been using Panamax 5400 for a couple of years as surge protection on 4x BL5, 2x BL8000 and 1x BL10.

I haven't noticed any improvement in audio quality, but have't got any burned chassis in the period as well.

It would be nice to know more about the effects of such equipment in the B&O speakers, specialy when they have output voltage regulators...

I’d like to know what’s been done to the beolab 50 and 90 to not recomend a power conditioner.

Hi again,

An explanation in 4 parts:

 

 

PART 1:

 

To start: There is a difference between a "surge protector" and a "power conditioner".

 

At the simplest level, a "surge protector" is a fuse or a circuit breaker. If the filament inside the fuse had too much current going through it, it melts and the circuit is opened - therefore everything downstream stops getting current and the lights go out. In this case, the "surge" is in the current - typically caused by the fact that it's being provided with 110 or 220 V RMS, and you (1) put in a too-small resistor somewhere (like a fork in a toaster, for example) or (2) put a bunch of resistors in parallel (say, 10 toasters making toast while you're heating up something in the microwave and using a hair dryer at the same time). Since I = V/R, then if R is very small, I gets very big and fuses get very unhappy - hopefully quickly enough to prevent something bad from happening somewhere else... That way the little filament gets hot and melts before the wires in your wall get hot and burn the house down.

 

The basic job of a "power conditioner" (a.k.a. "line conditioner") is to remove noise from the incoming power - so you get a perfect sine wave at 50 or 60 Hz (depending on where you live) with an RMS voltage of some level (say, 110 or 220 V RMS, depending on where you live) within the tolerance of whatever the power company promises. So, it should behave more like a bandpass filter. For example: the power company (in theory) delivers a sine wave to your house, and then your refrigerator and your air conditioning unit turn on and cause the sine wave to distort. The reason this would happen is that some devices (like motors and old-fashioned light dimmers, for example) use only a portion of the full sine wave in time - say, the first 90º out of the full 360º to get 25% of the light coming out of your lamp. So the load on your incoming power is varying in time in an unexpected way - which can cause the sine wave to have a slightly different shape (= distortion). When a sine wave is distorted, you typically have extra high-frequency components that are generated. In theory a "power conditioner" will remove those high frequency components and get you back to a sine wave.

 

HOWEVER: this is only a portion of the story, so let's look at some of the other portions.

 

 

PART 2:

 

You wouldn't buy a surge protector or a power conditioner without some device to protect. For the purposes of this discussion (because it's the question that started the thread) we'll assume that that device is a B&O active loudspeaker, so let's look at what's inside there.

 

On a basic level, a B&O loudspeaker contains the following (in reverse order of signal flow):

- loudspeaker drivers

- "power amplifiers" (which would be better called "voltage amplifiers that can deliver as much current as the driver demands" - at least theoretically)

- digital signal processing (with an ADC at the input and DACs at the outputs. This also includes a little analogue circuitry before and after to make the ADC and DACs happier about "talking" to other devices)

 

To keep all this running, we either have

- a battery (that provides a number of DC voltage "rails" generaged by chemistry)

- a power supply (that provides a number of DC voltage "rails" by converting the mains AC input somehow)

 

Without knowing HOW they work, the amplifiers and the analogue inputs and outputs of the processing (in an older loudspeaker like a Beolab 8000, the processing itself is analogue) do the following:

- "look at" an incoming signal (a voltage that changes in time)

- create a new version of that signal (i.e. in the amplifiers, a bigger version) using a constant voltage source (the battery or power supply delivering the DC), modulating it, and sending that to the output.

 

The error that CAN occur is in the assumption in that last statement that the voltage supply really is DC. Poorly-designed audio circuitry (for example, an amplifier) is designed based on the assumption that the power supply is delivering DC (in this case, constant voltage - with as much current as is required as its needed). If you make this assumption, AND the power supply does not deliver "perfect" DC (for example: 15 V DC that modulates ± 0.15 V AC at 120 Hz - this is called "ripple" in the voltage rail, in one common example), then this modulation in the voltage rail MIGHT cause the audio output to also ripple by some amount, possibly at the same frequency.

 

So:

 

IF

you have a poorly-designed power supply  

AND

the input of that power supply is anything other than a perfect 110 V RMS / 60 Hz (or 220 V RMS / 50 Hz) sine wave

THEN

the power supply's output MIGHT have a modulation in its "DC" output

 

AND 

 

IF 

you have an audio circuit (for example, an amplifier) that is intolerant of variations in the voltage supply (therefore it is poorly-designed)

AND 

you have a power supply that does not deliver "perfect" DC (for some reason) (therefore it is poorly-designed)

THEN

You MIGHT be able to hear (or at least measure) some artefact at the audio output of the device.

 

 

 

PART 3

 

There are two basic types of AC-to-DC power supply

 

1. the good'ol' "linear" power supply, which used 

- diode-based rectifiers to convert +/- sine-wave AC to positive-only (and/or  negative-only) "rectified" (absolution value of a sine wave) AC at twice the frequency of the input

- big capacitors as tanks of electrons to smooth that wave to something that looked a little like DC with an AC ripple added to it.

- regulators to hold the output at some voltage that's lower than we had, burning off unnecessary power as heat

 

2. a switch-mode power supply which:

- generates a square wave that has an adjustable pulse width

- smoothes that pulse wave into a DC level with capacitors

- adjusts the width of that pulse wave so that its average voltage over time is the voltage you want

- optionally: some microprocessor-based monitoring of the output voltage and/or the incoming current, to make sure things are behaving, and the power supply doesn't ask for too much from the mains and blow a fuse in the basement.

 

In both cases, the power supply doesn't produce "perfect" DC - but the "error" (the AC component) is different between the two design philosophies - and will also be different from design to design, and with different loads on the supplies.

 

Note that the modulation on the DC output of a power supply can also occur because it can't deliver what's being required of it. So it's not ONLY the fault of the mains input "signal" quality.

 

 

 

PART 4

 

Having done all of the setup listed above, I'll make a bit of a blanket statement:

 

These days, if you have an audio device (say, a fully-active loudspeaker that has an analogue input, for example) that needs a power conditioner, then someone didn't do a very good job designing the device.

 

In other words:

- the audio circuit (i.e. the amplifier inside the fully-active loudspeaker) should be designed to accomodate some modulation of its power from the power supply 

- the power supply should be designed to accomodate something other than a perfect sine wave from the power company (because it's a very safe assumption that it won't be a perfect sine wave)

 

So, if these are done well, then "conditioning" the incoming mains power with an external device is only removing something that would have been removed inside the device anyway...

 

This is especially true of a Bang & Olufsen loudspeaker, because we have designed the entire device, knowing the behaviours of the amplifiers, the analogue circuitry AND the power supply. So, we don't need to make any assumptions about how each of those things behaves (with respect to the voltage rails inside the product). Measuring those behaviours to their worst-case limits is on the basic list of the "things-the-engineers-do" to make sure that the audio output is not audibly infected by these issues. So, when I asked the electrical engineers here about whether you need a power conditioner for Beolab 17 or 18 (or 19 or 20) their paraphrased answer was "It probably won't make things worse, but why would you bother?"

 

(Don't get worried about the fact that I just said "audibly" in that last paragraph - I'm not trying to weasel out by saying "you can't hear it anyway, so it doesn't matter." I'm saying "any such artefact is measurable - but if it's at a level that is significantly below the signal level, or the noise floor of the system, then it is of no concern..." I'll never say "it's not there" - I'll just say "perhaps there are more important things to worry about than this particular issue.")

 

Cheers

-geoff

 

P.S. This doesn't answer the specific question in this thread about what's in the BL50 & 90 power supplies that could result in a "power conditioner" making things worse - but I think that I've written enough here - and besides, I wrote enough about that in the Technical Sound Guides for those loudspeakers - so best to find the answer there.

 

 

 

 

Amazing. We’re so lucky to have you here as a resource, Geoff. Thank you!

Curly:

Amazing. We’re so lucky to have you here as a resource, Geoff. Thank you!

I couldn't agree more

 

Geoff is a diamond from and for B&O

 

I've used one of these before. Normal 0 false false false EN-US X-NONE X-NONE I didn't find any special miracles. An ordinary surge protector, but handy. I connect sources and TV to it. I also got rid of a few extra surge PSU's I`d been using to charge my phones. I use my own 4 USB plugs for that. I connected the amplifier through another filter with DC locking.  I didn't notice any special sound improvement. This thing is more like another plaything. I quickly changed it and bought a decent model at airconservicing.org I like the new one more. All in all I decided not to bother with such small devices anymore. As my experience has shown - they don't work for long. Normal 0 false false false EN-US X-NONE X-NONE

Hello there

I have been struggling for months with my setup.

Since moving to my new house my home system eclipse with lab 5 and lab8000 and 4000 have a low level ground electric sound along with high hissing

I have had the power company monitor the electric and say it’s within tolerance

I have changed every PL cable

I have disconnected and reconnected the speakers

I have bought power conditioning surge protected leads

I have isolated wall speakers via insulation.

I have tried different devices and swapped Beolab speakers.

Bang and Olufsen changed the DSE board and power supply of the eclipse.

My screen sometimes flickers when I use the remote and sometimes the remote can be heard when volume changes but this seems to be fine now.

I have tried everything upon everything to stop this awful sound coming through my speakers

I had the power company install a 4amp socket directly from the incoming cables to eliminate the house cables and nothing has worked.

My next step might be to try and use a online / double conversion UPS to ensure a perfect voltage and perfect sine wave with no harmonics or dirty electricity.

Didn’t do any of this in my old house.

With what Geoff says the speakers can handle some variation but not what seems to be coming into my house in a semi rural area and the power company just say it’s all within tolerance.

Frustrated and ran out of ideas.

Seanie_230:

My next step might be to try and use a online / double conversion UPS to ensure a perfect voltage and perfect sine wave with no harmonics or dirty electricity.

Maybe buy an old oscilloscope (or "rent" an old stereo repairman, who owns a scope) to have a look at your power yourself?  If you're going to fix something that the utility says doesn't need fixing, it would be good to know if they are right or not.

Debugging: If you don't want to check the AC waveform yourself, or buy a regenerating AC power supply first thing, the easiest debugging step is to simplify: use line-in on one Beolab with a short cable to your phone (battery powered!) as source component.  Presumably when you plug earbuds into your phone it doesn't make noise, does it?  Likewise a cheap way to isolate a speaker is with a "true sine wave" UPS -- not a full regenerator but much, much cheaper and readily available -- but nevertheless it runs 100% from battery when you isolate by pulling the UPS's plug from the wall.  (The purchase won't be wasted; you can use it for your computer or something regardless of outcome.)

Seanie_230:

the power company install a 4amp socket directly from the incoming cables

Suspicious: I don't know the U.K. but that seems like a really odd, low, amperage -- and not to code if it doesn't go through your main feed.  Regardless, your own breaker box, and your neighbors', are still directly connected to it!  So if the milking machine is putting noise onto the wires, there isn't much that adding a new outlet, regardless of where it is connected **along the very same wire**, can do.  Versus if you're in the middle of coastal defence warning systems then you need the tin-foil hat and Faraday cages, not an AC regenerator.  I'm only being half-way humorous here: "low level ground electric sound along with high hissing" are not usually both from the same cause. [Edit: Actually, maybe one way you can get both: A power spike that ruined the power supply can cause the low-level sound from the speaker cone, but the hissing will be coming off the power supply itself.  Yet unlikely to be identical damage across multiple speakers.]

A PS Audio brand fancy-schmancy regeneration power supply here in the USA at 12 amps costs $5000 (15-amp $7000).  I guess compared to the price of an Eclipse that doesn't matter so much, but if all you need is to filter high-frequency noise from some rural industrial user, it's overkill.  And if your power supplies were damaged by an (un-)Lucky Strike, it's useless.  Anyway, good luck with the "isolation experiment": I may be full of nonsense about the cause(s), but at least have not run out of ideas!

@seanie_230:

Hi,

I'm afraid that I can't short-circuit B&O's customer service, however, I can help you to help them diagnose the source of the problem.

• Start by disconnecting all devices (EVERYTHING - loudspeakers and sources, including antenna connection if you have one) from the Eclipse. If the hum+noise is still there, then the problem is either inside the Eclipse, or some interaction between the Eclipse and your power+grounding situation.
• Add devices ONE AT A TIME and listen again. If the hum+noise appears when you add one device, then you've at least narrowed down the source of the problem, but not necessarily why it's happening. This will help customer service in trying to figure out the root of the problem.

The screen flickering may be an indication of something - but it might be unrelated to your hum+noise problem. I don't know about this.

The comment about "sometimes the remote can be heard when volume changes" - this may be a totally normal behaviour, depending on what, exactly, you mean. For example, if you play a sine tone - or a very constant tone in general - and change the volume while it's playing, you'll hear a small "bump" in the sound as the gain changes. This is typically not audible with most kinds of signals, because the signal is varying faster than the volume change.

Cheers
- geoff

Morning Trackbeo

thank you for your reply, it gives me some things to think about and test

I was reading your comment about connecting my phone to the speaker and this is a good idea, i was kind of thinking to do this with a Receiver 1 but the phone would do it for sure.

I am thinking of buying an online UPS that constantly cleans the power by converting AC to DC and then back again with a perfect sine wave.

Sorry for the 4amp socket it was only installed as a test to eliminate the house wiring, the power company had to install their monitoring device and it connected to the mains supply before the meter using a 4amp socket which they let me plug my kit into via an extension lead for a few minuets, the socket was removed when the device was removed.

Interestingly the low level humming was still there when my fise box was switched off and only the B&o kit connected to it.

Frustrated but more tests to do.

Thank you kindly

Sean

Geoff Martin:

@seanie_230:

Hi,

I'm afraid that I can't short-circuit B&O's customer service, however, I can help you to help them diagnose the source of the problem.

 

• Start by disconnecting all devices (EVERYTHING - loudspeakers and sources, including antenna connection if you have one) from the Eclipse. If the hum+noise is still there, then the problem is either inside the Eclipse, or some interaction between the Eclipse and your power+grounding situation.
• Add devices ONE AT A TIME and listen again. If the hum+noise appears when you add one device, then you've at least narrowed down the source of the problem, but not necessarily why it's happening. This will help customer service in trying to figure out the root of the problem.

 

The screen flickering may be an indication of something - but it might be unrelated to your hum+noise problem. I don't know about this.

The comment about "sometimes the remote can be heard when volume changes" - this may be a totally normal behaviour, depending on what, exactly, you mean. For example, if you play a sine tone - or a very constant tone in general - and change the volume while it's playing, you'll hear a small "bump" in the sound as the gain changes. This is typically not audible with most kinds of signals, because the signal is varying faster than the volume change.

Cheers
- geoff

Morning Geoff

thanks for coming back to me

I will try these tests this weekend, I have tried removing speakers PL cable one at a time but didnt remove the power cable, who knows maybe one of my speakers has a bad transformer so I will try that.

Just for info the weekend just gone everything was disconnected from the TV including the screen and the hum was still there, I also cannot hear it from the Eclipse speakers only the PL connected speakers which also hum when connected to an Essence MK in the same place or on another socket.

I will for sure try these tests and see if I can borrow a UPS from work just to put on Battery and see if the noise stops.

Another weekend of spaghetti :)

 

Hi 

Can the noise be triggered by other equipment in your house ?

I would shut down every electricity group except the one used by your TV + speakers.

It will rule out that other equipment (fridge, heating, air conditioning etc.) in your house is the root cause.

Good Luck 🤞

 

Hello there

thats been done, switched off all fuses and connected TV just to the cooker socket with all speakers to rule out the ring the system is on.

Also the house was disconnected from the “grid” and just incoming supply, smart meter and a socket.

The noise is there if using essence or TV with speakers.

The common thing is only the speakers which I need to follow Geoff’s plan and see if that helps.

Failing that it must be time to try a Online UPS

thanks for your thoughts 

I had a problem with a super-quiet but just audible hum on the BL90’s in between tracks. I went to pain to identify the cause….cables, the AURALiC’s, household appliances etc. 

The issue was the AURALiC DAC/XLR cables interacting with the Labs and the only way I could remove the problem was to install a PS Audio Steller P3 Regenerator (not Conditioner) to isolate the digital sources from the mains. I believe this achieved a number of solutions:-

a) it provides very clean power to the digital sources and eliminated the hum

b) it protects the equipment

c) clean power allegedly improves the sound, whereas a conditioner arguably is known to dull the dynamics.

d) the BL90’s have their own protection circuits and it is not recommended to add further protection (besides a Conditioner/Regen for each would be very expensive). The Stellar 3’s are probably the cheapest Regens on the market and are good for sustained 300w clean power supply and 750w short term/peak load.

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To add.

Adding a £2000 Regen to the BL90s and an AURALiC stack may be not to silly, adding it to a Essence/BL17 is not a cost-effective solution.

I would say the same to some of the power conditioner mention in this thread too.

However, be careful on using a PC UPS. PCs and a lot of PC equipment is designed to run at speed and is not necessarily the quietest of appliances in terms of electronic noise. They may add more to the problem than reduce?

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