| Search | Login/Register
   Home » Audio Discussions » It’s mad, mad, mad... electricity. (* posts, 25 pages)
  Print Thread | 1st Post |  
Page 21 of 77 (1,917 items) Select Pages:  « First ... « 19 20 21 22 23 » ... Last »
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  What lives in Symmetric Sound?..  The beginning of our journey is ALWAYS symmetrical...  Audio Discussions  Forum     19  175375  05-28-2004
  »  New  Always check power-line polarity...  The Cost of Knowing...  Audio For Dummies ™  Forum     11  112491  07-10-2005
  »  New  RAAL “Water Drop” tweeter for Macondo...  Your comment takes me by surprise...  Horn-Loaded Speakers Forum     77  925470  02-16-2007
  »  New  My feelings about new exciting audio products..  Vacuumstate...  Audio Discussions  Forum     25  265035  04-30-2007
  »  New  Musique Concrete horns..  These are now sold as Kornhent products...  Horn-Loaded Speakers Forum     6  108335  06-12-2007
  »  New  Compression drivers and the “clean signal”...  The NEW “Compression drivers and the clean signal”....  Horn-Loaded Speakers Forum     14  163703  07-12-2007
  »  New  Digi Redux; Drive 1 transport and iDAT-44+ DAC..  Moray James SPDIF!...  Didital Things  Forum     27  230856  09-28-2007
  »  New  Metal domes..  Try the one Lansche is using...  Audio Discussions  Forum     6  79041  11-08-2007
  »  New  The power AC Outlets?..  Where to Pick Up the Gong?...  Audio Discussions  Forum     2  43223  10-31-2008
  »  New  The Avicenna's failure is the great Avicenna success!..  New life for Avicenna...  Audio Discussions  Forum     8  84053  02-03-2009
  »  New  Internet and electricity..  Suboptimal. . ....  Didital Things  Forum     1  29373  01-07-2010
  »  New  Electricity... power strips and ac improvements..  Electricity... power strips and ac improvements...  Audio Discussions  Forum     0  16702  03-30-2010
  »  New  Another example of energy..  Tehran 230v...  Audio Discussions  Forum     1916  9958007  01-29-2011
  »  New  I good spot-light for a turntable?..  Reply...  Analog Playback Forum     15  154838  10-24-2010
03-23-2010 Post does not mapped to Knowledge Tree
oxric
Posts 194
Joined on 02-12-2010

Post #: 501
Post ID: 13216
Reply to: 13215
Impurities.
fiogf49gjkf0d
 Romy the Cat wrote:
...I local guy that I know did buy 2 month back a new PP2000 and it was measured horrible  - a pure faulty production and no quality control at all. The PurePower admitted that it was faulty production run and promised to fix it. Now, how many people out there are going in the extend I do and demand proper operation, how many people out there are running faulty PP2000 and do not know about it? My estimate is that the majority of PP2000 out there are just broken and are not to the own specification. They do sound good however. Still my agenda is not promote or demote PP2000 or any other power de but a consumer advocacy and my desire to have for myself a better performing product.  I am with PurePower for 2 years, had 7 of their units and my current is still has a faulty operation.

I do understand that PurePower is a work in progress and they do take care about their customers but that way how they do all of it is a bit ridicules for me and insult me with amateurism. They have a great product in my view, they sell it very fast and I hope they do fine financially. I do not know how much time and money they west for support but I know a LOT of people who keep fixing their PurePower units. So, why PurePower would not heir a truly knowledgeable engineer who would chaise all bags that PurePower has and convert it in a stable product, virtually “support free”? I good engineer-contractor would cost them let say $30K-$50K, who care – that is a single rain drop in a whole ocean…

The Cat


Romy:

Given how little short shrift you had given to other manufacturers in the past, I must say I had been wondering about why you had not written the above more explicitly before. Not having dealt with the company myself as an end-user, I felt it was  not quite right for me to comment. I also kept in mind that I had placed an order for one and did not want to upset people (not a concern you ever seem to have, which is why, among other things, your site has such appeal to me).

I am cancelling my order for the PP2000, not because of what you had written above -I decided to do that yesterdy already when I read PurePower's recent post in this thread ignoring  the service issues you had repeatedly raised, and just blather on about how other equipment must be at fault. I would probably have done so anyway given the quality control issues, and in the hope that the  next line or generation will have addressed these.

I have had dealings with a rather prestigious and reputable British company recently, and had to start a thread on an  internet forum to get their attention and correct some blatantly overpriced  service charge. That thread was then deleted by the forum administrator. At least the beauty of your site is that this thread cannot simply vanish into thin air. I think it is very wrong when organisations, whether audio or not, use their insidious influence to achieve such results. This was one of the very few occasions I have posted online and I was so shocked that an issue of interest to all consumers could be swept under the carpet in such a fashion. I have fortunately saved the thread and would one day post it again somewhere where it will not run the risk of being removed without justification or notification.

If you have read my previous  posts, I hope that it is clear that I think that manufacturers should also be treated fairly, whether by you or anyone else. Nonetheless, for anyone to have gone through 5-6 units and to have someone from PurePower post on your website in the same thread and completely ignore your less than positive experiences displays such a complete disregard for existing and potential customers, and for their public image, that I am still reeling from it.

PurePower presumably got quite a few sales as a result of this thread, which was in spite of its honesty and the criticism, fairly complimentary of their flagship product. Potential buyers of the PP2000 ought of course to reflect on whether they want to order now or whether they opt to wait and hear some official confirmation from the company showing that they are aware of the quality control issues, that these have been investigated  and have been resolved. I know I am choosing the second option.

Kind  regards
Rakesh
03-23-2010 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #: 502
Post ID: 13217
Reply to: 13216
Better sounding and better functioning prodacts.
fiogf49gjkf0d

Rakesh, first of all I have expressed the same sentiments a few times before in this threw. Second, I have to admit that is other company would have the same problem with ratability and support as PurePower does then I would behave differently. However, in case of the whole PurePower saga there are a few moments that I am considering.

1)    PurePower is the only know o me de that sound good. That set all other arguments apart.

2)    PP2000 is working flawlessly in my playback for 1.5 year and now in Bill’s playback. In it faulty as it has the fizzing effect but it sound perfectly fine.

3)    The topology of the PurePower units is that no mater what you do it WILL be dependant from the characteristics of the load. Do not forget that PurePower run global feedback from output and type of the load is the factor for this topology.

As you understand I am not in the business of sealing PP2000. My motivations are way more egotistic and all that I would like to have is better performing power solution in my own home. I do not give as damn about their sales numbers. I would like to have more folks that I know who use PP2000 and who might discover a new perks how to get better sound from it but it is all interest I have.

I do not know is your decision to buy or not to buy is good or bad. I have no idea how 220V PP2000 would sound and if it worthy for you.  I think to make class D amp to swing more voltage is different amp is needed, but I am not sure.  I personally very welcome any criticism toward to PurePower that would enable us the users to end up with better sounding and better functioning generators.

The cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
03-23-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #: 503
Post ID: 13218
Reply to: 13217
The Ghosts in the Dirty Laundry
fiogf49gjkf0d

Sure, there's plenty APS or any hi-fi component "manufacturer"/seller won't say, and one of the most common misunderstandings they quietly exploit is the die-hard audiophile notion of the "universal component", the old "plug-and-play" gambit.

If there is a "universal approach" to power supply, one that works equally well for inductive, capacitive and resistive loads of all stripes, then I am unaware of it.  And this is true all the way up to giant laboratory grade power systems, and the power grid, itself, for that matter.  Although some "empirical" research has been done on wave forms, load ratios and frequencies versus load types, I know of no rational, systematic, "subjective" evaluation of any of this power treatment/regeneration stuff as it relates to serious listening to complex music via hi-fi, bullshit "testimonials" notwithstanding.  I assume this is because there has so far been no need to go this far; rhetoric and hype alone have done fine for sales, to date.

Of course, I'm dying to let loose with another flurry against APS' "QA"; but the truth is I'm only venting my personal frustration at feeling so close -  yet so far away -  from a personal solution to this most infernal of hi-fi poltergeists.


Paul S

03-23-2010 Post does not mapped to Knowledge Tree
clarkjohnsen
Boston, MA, US
Posts 298
Joined on 06-02-2004

Post #: 504
Post ID: 13219
Reply to: 13204
Methodological “CLEANNESS”
fiogf49gjkf0d
Methodological “CLEANNESS” is difficult to achieve. As the co-designer of several sets of tests involving several actual astronauts (this was some time ago), one had to do it right owing to their busy schedules. So thinking-it-through really counted.

Later when we were doing stuff like that at The Listening Studio I tried to apply the same principles, but it was well-nigh impossible. How to stabilize RFI/EMI, just for instance? Or, as we are discussing here, AC power.

In audio one must pretty much learn to live with DIRTINESS and adapt one's methodologies to that situation.

clark
04-01-2010 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #: 505
Post ID: 13249
Reply to: 2931
The electricity in my suburb.
fiogf49gjkf0d
The holly shit! How bad my electricity was in downtown and it was bad! However, here in suburb it is not even bad but 10 times worse. In city it just produced bad sound. Here, in West Woburn, it not just does bad sound but it almost translates the things in Spanish.

I set up Injection channels with a full range Milq – just to play something while I am unpacking and it was beyond any imagination – the music is hardly recognizable, the words are badly recognizable. How the hell they do it? I feel that here in new place it will be a big electricity fight.

The Cat


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
04-02-2010 Post does not mapped to Knowledge Tree
Bill
Kensington, NH
Posts 117
Joined on 03-15-2010

Post #: 506
Post ID: 13250
Reply to: 13249
Suburban shitty electricity
fiogf49gjkf0d

I've been fighting the electricity for 30 years in the woods of Kensington, NH. but nobody believed me that it copuld be worse than in the city with all of its problems. Even guys I've had up here from New York couldn't believe how bad it is. And its not voltage sag but just horrendous noise on the lines.
Sounds like Romy needs his PurePower unit back again. Guess it'll be my loss until my units arrive. When do you wnat it back Romy?

 

Bill

04-02-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #: 507
Post ID: 13251
Reply to: 13250
Will We Ever Learn?
fiogf49gjkf0d
Bill, if you have fearlessly ordered a PP2000, and if you actually receive a functioning unit at some point, I hope you will find a way to test and compare it directly to Romy's repeatedly and selectively modified (yet still not correct...) unit.  This might be interesting to both you and Romy, and I hope it will also demonstrate - if just this once - that APS can ship a randomly-selected, regular production unit that meets its own specs and also gets the job done.

Regarding suburban BEP misery, I mentioned way up this thread that my previous (suburban) house was fed directly from a large, pole-mounted transformer, and that power was still mostly horrendous (although it was better more often than it is in my present suburban house...).


Best regards,
Paul S
04-02-2010 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #: 508
Post ID: 13252
Reply to: 13250
Nothing until I put a bigger bathtub in….
fiogf49gjkf0d
Thanks, Bill, I do not need it yet. I estimate that I am a good 2-5 weeks away from the time what I might just stat play with my playback at any more or less refined level. Also, I would like as well you to compare your PP2000 with mine, not that I support Paul’s attitude toward to PurePower but I feel that the comparing does has some merit.

I got the motor-generator assembly today. I have no use for it for now and it will be sitting in my driveway from the time being. I need to fund an electrician who wiling to work with it….

The  caT


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
04-23-2010 Post does not mapped to Knowledge Tree
Bill
Kensington, NH
Posts 117
Joined on 03-15-2010

Post #: 509
Post ID: 13338
Reply to: 13252
PP2000 evaluation
fiogf49gjkf0d
Have purchased two of the units for evaluation, using them for right and left channel and sources. Have also been using Romy's unit for the surrounds. Each running at about 35-45%. Sound is phenomenal; best I've ever heard from my system.
One problem was that when they firwst arrived, one unit would only run on wall current and wouldn't charge the battery, but would run off of them. Opened the front to check the battery connections and they all looked okay, and when I reclosed the unit it was running normally. Go figure!
Romy was over last night to retrieve his unit and brought along an oscilloscope. Results were interesting. One new unit had an almost perfect sine wave with the second only showing a mild distortion on one peak.
Even more interesting, when Romy tested his unit, the sine wave was better than what he had seen and recorded at this site. Guess my house has both positive and negative gremlins.
Anyway, am happy with the results, but they have brought out some problems with my speakers that were masked by the crappy electricity that I'll have to look into.
Romy also brought along some phenomenal russian recordings that blew my socks off. Wish I had had time to copy them but maybe next time he's here.
Thank you Romy for your help.

Bill
04-24-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #: 510
Post ID: 13346
Reply to: 13338
Slop Factor
fiogf49gjkf0d
Bill, what I find interesting is not the fact that the units vary one from the other in terms of measured performance, or each in its (in)ability to charge its own battery, rather I notice that you seem "happy" with the performance of all the units in your system, irrespective of their [measured] "faults", and you do not describe any problems or even any differences, unit to unit,  in the waySleep the units are doing their respective jobs in your system.  May we assume from this that, practically speaking, all units are equal in terms of aural in-system performance, and that all are equally acceptable, now that the "delivered bad" one is charging its battery, after all?

It almost sounds as if the "problems" (other than the totally debilitating problems) with these units are not getting in the way of their positive contribution to the the sound of a given system that can reveal the contribution.  If this is so, so far, then there would seem to be a "slop factor" built into the design and/or execution of the PP2000.

A big slop factor would certainly bode well for APS (and its customers), since it has not escaped notice that one of Bill's two units was not functioning properly when and as he received it; ie, maybe APS can yet get by on a 50% self-spec failure rate, as long as the unit none-the-less "gets the job done".

Bill, I hope you will refine your observations.  If nothing else, I hope you will comment on any differences (or not...) between wall and battery sourced power via the PP2000.

Best regards,
Paul S
04-25-2010 Post does not mapped to Knowledge Tree
clarkjohnsen
Boston, MA, US
Posts 298
Joined on 06-02-2004

Post #: 511
Post ID: 13350
Reply to: 13346
What this tells me is...
fiogf49gjkf0d
...once again listening outpaces measuring. Still, the measurements are good to have.

As I know all three of you who have these units, I am totally inclined to accept your results -- and put a PP on my want list.

clark
04-25-2010 Post does not mapped to Knowledge Tree
Bill
Kensington, NH
Posts 117
Joined on 03-15-2010

Post #: 512
Post ID: 13351
Reply to: 13350
Pp2000
fiogf49gjkf0d
Clark: You heard what units can do in my place.
Romy: Took your advice and added high frequency rolloff to the woofers. The sound did clean up the way you predicted. Now if I can get my subwoofer amplifier back asnd rebalance the system.
Paul: Am erxtremely happy with the results of adding the two units. Best sound I've had from my system. Much tighter bass, souindstage thicker with air between the instruments, wider sound stage, and on certain recordings, ambiance information extends behind and above my listening posiution, almost as if the surrounds were turned on. Have never heard this before in my system. 
Fnially, some harshness in the upper mids and highs has been erased.

Am going to try to get a third unit so I can also power the video and subwoofer amp to completely isolate my system.

Bill
04-25-2010 Post does not mapped to Knowledge Tree
clarkjohnsen
Boston, MA, US
Posts 298
Joined on 06-02-2004

Post #: 513
Post ID: 13352
Reply to: 13351
For the record...
fiogf49gjkf0d
...I heard only the one (Romy's) unit at Bill's. Your descrip of the sound stage reminds me of that one peak day we had at The Listening Studio, so long ago.
04-29-2010 Post does not mapped to Knowledge Tree
maxzimum
Posts 9
Joined on 07-06-2009

Post #: 514
Post ID: 13378
Reply to: 13352
Load on the PP?
fiogf49gjkf0d
Is anyone using their Purepower unit with Power amps? If yes, what load?

 I hear loud buzzing when I plug in my tube amps - each uses about 30% load on the PP. AM wondering if this is an issue with my amps power supply or the PP or my mains voltage.

Thanks
04-29-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #: 515
Post ID: 13381
Reply to: 13378
Par for the Course, Apparently
fiogf49gjkf0d
Max, are you saying that your unit does not hum in use until it is loaded >60%?  Does it hum even when running loaded but unplugged (ie, when it is running from battery power only)?  Would you please describe the hum?

You should be able to find the info you are asking for, up the thread, although I cannot conclude from your question whether you have properly addressed generic grounding issues, per se.



Best regards,
Paul S
04-30-2010 Post does not mapped to Knowledge Tree
maxzimum
Posts 9
Joined on 07-06-2009

Post #: 516
Post ID: 13384
Reply to: 13381
Buzz
fiogf49gjkf0d
Hi Paul,

It's more a buzz than a hum. It buzzes when I put either amp on. ie: at ~30% load. I have not tried other loads since I don't know what would be a appropriate load to test it with other than audio equipment, of which I have nothing other than what's connected.

The noise is from within the unit itself and not from the speakers.

I have a dedicated ground for my setup. It is a copper rod that goes about 60' into the ground and has been made taking all considerations. We have a high water table in the area, hence the soil is always moist. This ground is tied with the common house ground at the mains (have tried it both ways). The Neutral to Ground Voltage at the setup is <3V (I have 220-230V supply). I have a dedicated circuit from the mains for my audio. I also have a captive diesel generator (we have frequent power cuts) and the hum/buzz is audible when using the generator too.

I am trying to determine whether its a problem with my Amplifier power supply or something else.
04-30-2010 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006

Post #: 517
Post ID: 13390
Reply to: 13384
$3k Crap Shoot
fiogf49gjkf0d
Max, it sounds like this is not a case of ground (loop) hum, although 3V might well cause problems with HE speakers, depending on how the system grounding is stacked.  As a control, try running the APS off its battery while it's loaded (ie, the amp is plugged into the unit, while the unit itself is unplugged).  You may have to deal with your amp grounding separately during the course of this experiment.  According to reports from other users (available for your perusal, above), unplugging the APS generally stops the buzz, which often seems to be +/- "mechanical", generated by the unit's self-charging system.  Others also say that they plan to put their units someplace where they can't hear the self noise, since, although APS agrees that the noise is a problem, yet APS do not actually correct the problems they periodically acknowledge.

Not having $3k to simply piss away these days, I have held off on purchasing one of these, waiting until I get some sense that APS gives a damn and has instituted a meaningful QA/CS program.  But the more I hear about it, the more it sounds like a $3k crap shoot.



Best regards,
Paul S
04-30-2010 Post does not mapped to Knowledge Tree
beachbum
New Orleans area
Posts 16
Joined on 02-19-2009

Post #: 518
Post ID: 13391
Reply to: 13390
No reply from APS
fiogf49gjkf0d
I ve had my PP2000 for more than a year now and could not be any happier with the job it does for the sound my system delivers. I emailed them last week asking about any updates to the unit. As of this time no response. I believe and my ears back it up PP2000 is a vital part of the presentation and delivery my system gives and i would not be a happy audiophile if it had to go but i dont understand APSs business practice and treatment of paying customers.
Mike



I Think the Volume needs to be Turned Up
04-30-2010 Post does not mapped to Knowledge Tree
Bill
Kensington, NH
Posts 117
Joined on 03-15-2010

Post #: 519
Post ID: 13394
Reply to: 13391
PP2000 buzz
fiogf49gjkf0d
One opf my amps buzzed when connected to the Pure Power but it was due to the fact that the manufacturer forgot to laquer the lams on an inductor.
Have run bot my and Romy's units up to 100%, and even shut down Romy's unit overdriving it with as Crown Maxcro Reference. Have never heasrd any buzzing or hum from the unit itself. 
On the other hand you cvan get some buzzing from your amps if you have not adjusted the little screw on the front of the unit. 

Bill 
04-30-2010 Post does not mapped to Knowledge Tree
PurePower
Ayr, ON
Posts 44
Joined on 05-26-2009

Post #: 520
Post ID: 13395
Reply to: 13391
PurePower Customer Service
fiogf49gjkf0d
Hi Mike,

I'm happy to hear your PurePower listening experience is great, but it upsets me to hear anyone felt they didn't get responsive customer service. That's my personal responsibility and I'm always available by email or phone. I apologize if your email went astray. PurePower is small enough that you can always reach a principal directly. Our personal email addresses are on our contact pages at www.PurePoweraps.com. We do not take customer service or technical support lightly - it's  literally our livlihood.

The short answer to your question is that there have been no upgrades to the 2000 since yours was built that would affect its sonic performance. We do make minor improvements on a continual basis, and we are always willing to bring a customer unit up to the latest revision. You are more than welcome to call and we can determine the production date of your unit and if there is any benefit to you to sending it in.


04-30-2010 Post does not mapped to Knowledge Tree
Meiko41
Posts 9
Joined on 07-17-2009

Post #: 521
Post ID: 13396
Reply to: 13395
PurePower Customer Service still exists ?
fiogf49gjkf0d
I am glad to hear that APS plans to reply to its customers. So I can hope myself to have some answers one day. I am waiting for only few months... ;-)
04-30-2010 Post does not mapped to Knowledge Tree
PurePower
Ayr, ON
Posts 44
Joined on 05-26-2009

Post #: 522
Post ID: 13397
Reply to: 13378
Maxzimum's buzz needs to be minimised.
fiogf49gjkf0d
Hi Max,

If you have buzzing that is audible outside the PurePower case, or audible from a listening position, the behavior is not normal. The probable source is a capacitor. Caps can hum in the same way as transformers - the foil expands and contracts and can vibrate at 60 cycles in an effect that is similar to transformer magnetostriction. You should contact us to arrange for service.
05-01-2010 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,160
Joined on 05-28-2004

Post #: 523
Post ID: 13398
Reply to: 13397
The nonsense of Buzzing capacitors?
fiogf49gjkf0d
 PurePower wrote:
Hi Max,

If you have buzzing that is audible outside the PurePower case, or audible from a listening position, the behavior is not normal. The probable source is a capacitor. Caps can hum in the same way as transformers - the foil expands and contracts and can vibrate at 60 cycles in an effect that is similar to transformer magnetostriction. You should contact us to arrange for service.

I am sorry but it is nonsense! I am not electronics wizard but from a very commence sense it sounds to me absurdish that a capacitor can buzz.  The whole idea of a capacitor is a sequential layering of conductor and dielectric. If the layering is not done tight then the conductors might move up to the point but it happened ONLY in failed capacitors that must not be use anyhow.  However, if a layer moves up to the point that it auditable buzzes then the capacitor is way passed the moment when it might be safely used. The point is that if a cap is so bad in quality that the layers buzz then the cap does not perfume it’s capacitive duty sand most likely will be shorted very soon. Still, I do not believe that commercially made caps, that wounded by high tension-machines would buzz.

The Cat
 


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
05-01-2010 Post does not mapped to Knowledge Tree
beachbum
New Orleans area
Posts 16
Joined on 02-19-2009

Post #: 524
Post ID: 13400
Reply to: 13395
PurePower thanks for the reply
fiogf49gjkf0d
Will get in touch this week and thanks for the quick response.
Mike



I Think the Volume needs to be Turned Up
05-01-2010 Post does not mapped to Knowledge Tree
PurePower
Ayr, ON
Posts 44
Joined on 05-26-2009

Post #: 525
Post ID: 13401
Reply to: 13398
Yes, Romy, most AC capacitors buzz.
fiogf49gjkf0d
In the world or audio you learn new and interesting facts every day.
 
AC caps (ceramic, electrolytic, polyester and polypropylene metallized foil types) can buzz at various frequencies. This is not nonsense, and is quite normal behavior; it is common sense if you stop to think about it. As the voltage switches from positive to negative in the presence of AC the film stretches and shrinks with each cycle, just as a transformer lamination stretches and shrinks. 

Transformers, coils and capacitors  are all capable of acting as little door buzzers.
 
Unfortunately cap manufacturers do not include specifications for audible noise in their technical data, so those of us using AC caps in applications where audible sound levels are critical have to test each type carefully and specify only those that meet our own QC procedures for audible noise.

Interestingly, the tendency to hum is entirely unrelated to the quality, price, or electrical specifications of the cap. So a noisy cap does not indicate a failing or low quality cap at all.
 
For many of the AC caps in PurePower units we have worked with a small custom manufacturer that has developed a unique folding configuration to reduce the tendancy to vibrate. Several of the hand wound audio grade cap manufacturers have worked very carefully to develop quiet caps through trial and error to come up with the ideal winding technique, and one California audio grade custom cap manufacturer told me it is a skill that varies from employee to employee.
 
Usually, the sound produced by noisy caps is below a level that is audible outside the component case, but occasionally they can be loud enough to be objectionable.
 
p.s. It would not surprise me at all if there were capacitors happily humming away inside some very high end audio equipment. Fortunately, the sound level is usually proportional to load, so they would only make noise when the music is loud, and catching them would be like trying to see if the fridge light goes out when you close the door.
 
Page 21 of 77 (1,917 items) Select Pages:  « First ... « 19 20 21 22 23 » ... Last »
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  What lives in Symmetric Sound?..  The beginning of our journey is ALWAYS symmetrical...  Audio Discussions  Forum     19  175375  05-28-2004
  »  New  Always check power-line polarity...  The Cost of Knowing...  Audio For Dummies ™  Forum     11  112491  07-10-2005
  »  New  RAAL “Water Drop” tweeter for Macondo...  Your comment takes me by surprise...  Horn-Loaded Speakers Forum     77  925470  02-16-2007
  »  New  My feelings about new exciting audio products..  Vacuumstate...  Audio Discussions  Forum     25  265035  04-30-2007
  »  New  Musique Concrete horns..  These are now sold as Kornhent products...  Horn-Loaded Speakers Forum     6  108335  06-12-2007
  »  New  Compression drivers and the “clean signal”...  The NEW “Compression drivers and the clean signal”....  Horn-Loaded Speakers Forum     14  163703  07-12-2007
  »  New  Digi Redux; Drive 1 transport and iDAT-44+ DAC..  Moray James SPDIF!...  Didital Things  Forum     27  230856  09-28-2007
  »  New  Metal domes..  Try the one Lansche is using...  Audio Discussions  Forum     6  79041  11-08-2007
  »  New  The power AC Outlets?..  Where to Pick Up the Gong?...  Audio Discussions  Forum     2  43223  10-31-2008
  »  New  The Avicenna's failure is the great Avicenna success!..  New life for Avicenna...  Audio Discussions  Forum     8  84053  02-03-2009
  »  New  Internet and electricity..  Suboptimal. . ....  Didital Things  Forum     1  29373  01-07-2010
  »  New  Electricity... power strips and ac improvements..  Electricity... power strips and ac improvements...  Audio Discussions  Forum     0  16702  03-30-2010
  »  New  Another example of energy..  Tehran 230v...  Audio Discussions  Forum     1916  9958007  01-29-2011
  »  New  I good spot-light for a turntable?..  Reply...  Analog Playback Forum     15  154838  10-24-2010
Home Page  |  Last 24Hours  | Search  |  SiteMap  | Questions or Problems | Copyright Note
The content of all messages within the Forums Copyright © by authors of the posts