EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: GTA on April 13, 2021, 05:45:53 pm
-
I forgot the U-tubers name (SDG Electronics) but remembered that he posted a video about isolation transformers so I searched U-tube for isolation transformer and this video came up: https://www.youtube.com/watch?v=PaDzQ3V0Zg8 (https://www.youtube.com/watch?v=PaDzQ3V0Zg8)
It's only about 6 mins long so I watched it out of curiosity as I assumed he would be talking about isolation in the audio processing stage *AFTER* the PS. I admit I'm not the sharpest knife in the drawer but from what I understand about electronics/electrical he started blabbing about cleaning up the mains input to create better audio quality...HUH?
As mentioned, I'm no PHD but does he make any sense after about 4:15 into the video? BTW, he started to flog an "audiophile power regenerator" near the end of this vid. The company he represents is PS Audio and the "power regenerator" series is here: https://www.psaudio.com/product-category/power-regenerators/ (https://www.psaudio.com/product-category/power-regenerators/)
Please chime in as I'm interested in what more knowledgeable members know about this, as I feel I'm missing something if people actually purchase this stuff. Maybe there is a market for this regenerator for some other purpose, but I'm only referring to audio equipment.
-
Classic audiophoolery!
-
Wow
Through regeneration, the P15 creates a completely new AC waveform that adds missing energy back onto the power line to correct for serious issues, such as distortion and voltage fluctuations
Well, for $7500 USD I guess you'll convince yourself it's doing something.
-
It is amazing just how dumb and gullible audiophools are.
You don't need to be an EE, but it is not that hard to figure out basic power supply stuff. This is intentional ignorance.
I see how you can argue about nuances of the audio produced by different analog parts, but there is no excuse for $900 mains cables. Especially when they go into a switching power supply in most cases anyway.
If it adds energy back, be careful to avoid any loops in your power supply system, you don't want infinite energy.
-
There is no end of silliness in the audiophool world, but that dead horse has been beaten to a pulp. People do all kinds of nutty things, like special high end power receptacles and dedicated circuits with special wire, but I guess they forget about the cheap aluminum cable and standard transformers and gear that runs the many miles from their home to the power company.
I remember reading something somewhere where a guy was talking about the sonic qualities of various bulk filter capacitors placed before a 3 terminal regulator. The placebo effect is real, if you think something will make your audio sound better, it will sound better to you.
-
After seeing some of your replies, I perused the PS Audio website some more, and many of their other products are just that - Audiophoolery. Even their product descriptions are pure marketing wankery, like their PowerPort Classic and Noise Harvester. :wtf:
Looks like they're trying to give Monster Cable a run for their money :-DD
Wow...just WOW!!!
-
Well, as the saying goes, a fool and their money are soon parted.
As silly as I think it is, I don't think it's any worse than spending obscene amounts of money on useless rocks (diamonds, etc), or ugly artwork. There are paintings worth millions of dollars that I would not take for free if I was not allowed to sell it.
-
It is amazing just how dumb and gullible audiophools are.
Another point of view, however, is that audio magazines have no incentive to disprove the products of their advertisers.
-
:palm:
edit:
One use case is valid, however.
Where I think this can stem from is old amps with very picky PSUs.
Brian May's guitar tech/sound engineer got fed up with trying up connect to local power supply or use inverters that were terrible.. and needed a more dependable solution.
https://youtu.be/jJ_OamX-PA8?t=1728
-
:palm:
edit:
One use case is valid, however.
Where I think this can stem from is old amps with very picky PSUs.
Brian May's guitar tech/sound engineer got fed up with trying up connect to local power supply or use inverters that were terrible.. and needed a more dependable solution.
https://youtu.be/jJ_OamX-PA8?t=1728 (https://youtu.be/jJ_OamX-PA8?t=1728)
A rock band by the name of AC/DC uses what they call a "kee-KOO-soo" to convert 120V to 230V and keep the AC regulated. Kikusui starts at 9:22
https://www.youtube.com/watch?v=j5C7GKGxICg&t=9m22s (https://www.youtube.com/watch?v=j5C7GKGxICg&t=9m22s)
-
I don't think they know how to bilk these phools to the maximum extent possible. The top-of-the-line PowerPlant 20 power regenerator thingy is only $9,999. Man, I think they could easily get twice or maybe three times that much for it :-DD
https://www.psaudio.com/products/directstream-power-plant-20/ (https://www.psaudio.com/products/directstream-power-plant-20/)
-
The isolation transformer can remove ground loop issues, or if some of your AV equipment has a switching power supply with that annoying class Y cap and poor hipot isolation. I used an isolation transformer to power my old Sony 757 HiFi VHS from ~1989. It removed a nasty 60Hz humm/buzz sitting at around ~ -82db making the noise floor below -96db, slightly better than the VCR's advertised noise floor. This was heard clearly and the 60Hz hum was eliminated with that transformer.
I could not use such a transformer on my PC feeding the VCR audio inputs since my isolation transformer was only capable of ~75 watts and my PC was over 300 watts at the time. There was no point in isolation my amp as it already had an old fashioned linear transformer power supply. Yes, my RCA cables had heavy-duty thick copper braided shields.
So, yes, if your situation creates such a problem, a 'strategically' placed isolation transformer can solve some specific problems. If you do not have an audible fundamental multiple of mains entering your signal path due to a limitation in the mixing of audio equipment, an isolation transformer wont do anything for you.
My isolation transformer cost me ~25$ in total. It was 2 back-back transformers, 120v in to 48v, then a second identical one took the 48v in and gave me back 120v. They were the old split-bobbin style transformers meaning an extra hipot isolation. There was no regulation or any filtering.
-
I don't think they know how to bilk these phools to the maximum extent possible. The top-of-the-line PowerPlant 20 power regenerator thingy is only $9,999. Man, I think they could easily get twice or maybe three times that much for it :-DD
https://www.psaudio.com/products/directstream-power-plant-20/ (https://www.psaudio.com/products/directstream-power-plant-20/)
What if the manufacturer of you audio equipment tuned and designed their hardware with their poor, out of spec, normal AC outlet power. Maybe such perfect power will make things worse.
-
I don't think they know how to bilk these phools to the maximum extent possible. The top-of-the-line PowerPlant 20 power regenerator thingy is only $9,999. Man, I think they could easily get twice or maybe three times that much for it :-DD
https://www.psaudio.com/products/directstream-power-plant-20/ (https://www.psaudio.com/products/directstream-power-plant-20/)
What if the manufacturer of you audio equipment tuned and designed their hardware with their poor, out of spec, normal AC outlet power. Maybe such perfect power will make things worse.
No Brian, you don't understand what's going on. It will sound better no matter what. It's audiophoolery. It's all in the mind, that's why they don't publish or even attempt to make any objective measurements with instruments (test equipmnent). If you are an audiophool, and you buy this, your brain will believe it sounds $10,000 better than before you had it. How else do you think these people stay in business?
-
I know of a couple of people I have come across that would go gaga over these products.
I remember sitting in an electronics class in the 80's and the instructor was going off topic to tell a story of how people get sucked into buying audio amplifiers that has a bandwidth "up to 100KHz". Using this story and explaining that "oxygen-free, piezo effect, high thermal nuclear reaction conductors" doesn't make $300 speaker cable sound better to these people. In the end, they will still be enticed to buy this crap based on sales tactics and marketing claims.
So yes. In the end, people believe in the placebo effect. :-//
-
I know of a couple of people I have come across that would go gaga over these products.
I remember sitting in an electronics class in the 80's and the instructor was going off topic to tell a story of how people get sucked into buying audio amplifiers that has a bandwidth "up to 100KHz". Using this story and explaining that "oxygen-free, piezo effect, high thermal nuclear reaction conductors" doesn't make $300 speaker cable sound better to these people. In the end, they will still be enticed to buy this crap based on sales tactics and marketing claims.
So yes. In the end, people believe in the placebo effect. :-//
Read any audiophile review of any product in that category, and check out the phrases they use, like these -
Greater separation and resolution
No glare or grit
An effortless presentation to every recording
an innately natural, unforced sound
no hint of harshness or whatever
Palpable as all get out
What do those phrases mean? Is it common knowledge exactly what they are implying? How do you measure "glare" or "grit". What does an "effortless presentation" look like on the display of an oscilloscope?
It's all bullshit!
-
What he described as a "power regenerator" looks to be almost as if it were an online UPS unit without batteries - where the output is a PWM generated low distortion sinewave that powers your product. Perhaps the term "regenerator" is common along the audiofolk, I don't know.
Obviously the other topics raised here are valid: a half decent audio system must have a high AC line noise rejection, otherwise you will get all undesired effects; must have a high filter capacitance to hold the DC voltage in power stages; use an isolated power supply to eliminate ground loops, and so on.
-
A rock band by the name of AC/DC uses what they call a "kee-KOO-soo" to convert 120V to 230V and keep the AC regulated. Kikusui starts at 9:22
https://www.youtube.com/watch?v=j5C7GKGxICg&t=9m22s (https://www.youtube.com/watch?v=j5C7GKGxICg&t=9m22s)
I am going to go out on a limb here.
If you dress like a naughty schoolboy, yet you are one of the meanest guitar players in rock history, who plays at sold-out stadiums, you can indulge in any sort of audio sorcery you desire.
-
Wait until he finds out mains electric oscillates 50 or 60 times a second and has hundreds of volts difference between the peaks.
-
I know of a couple of people I have come across that would go gaga over these products.
I remember sitting in an electronics class in the 80's and the instructor was going off topic to tell a story of how people get sucked into buying audio amplifiers that has a bandwidth "up to 100KHz". Using this story and explaining that "oxygen-free, piezo effect, high thermal nuclear reaction conductors" doesn't make $300 speaker cable sound better to these people. In the end, they will still be enticed to buy this crap based on sales tactics and marketing claims.
So yes. In the end, people believe in the placebo effect. :-//
Actually ... the bandwidth was related to amplifier slew rate and "speed" errors in the past; a "20kHz" amplifier would be more and more inaccurate past a few kHz which would make even 1-2khz sounds sound bad (by damaging the higher harmonics). Sounds are not sinusoids; a sound with a 1kHz fundamental might even take 10kHz of bandwidth or more.
On top of that, mixing different sounds multiplies the necessary bandwidth. Mix a few sounds at 2-3kHz and their first 3 harmonics, you already need many tens of kHz of bandwidth.
-
What he described as a "power regenerator" looks to be almost as if it were an online UPS unit without batteries - where the output is a PWM generated low distortion sinewave that powers your product. Perhaps the term "regenerator" is common along the audiofolk, I don't know.
That Kikusui thing? Or are you referring to a different "he"?
The Kikusui box looked to me like a programmable AC power source. I have a much older device of a similar concept made by California Instruments. It's essentially a big class B amplifier driven by a sine wave oscillator and feeding an output transformer. It can deliver something like 0-300V at 20Hz to 5kHz at full rated power of 500VA and will go beyond that range derated. Niche thing but very useful in certain applications. Works great for running British and European discharge lamps and control gear from proper 50Hz power.
-
I know of a couple of people I have come across that would go gaga over these products.
I remember sitting in an electronics class in the 80's and the instructor was going off topic to tell a story of how people get sucked into buying audio amplifiers that has a bandwidth "up to 100KHz". Using this story and explaining that "oxygen-free, piezo effect, high thermal nuclear reaction conductors" doesn't make $300 speaker cable sound better to these people. In the end, they will still be enticed to buy this crap based on sales tactics and marketing claims.
So yes. In the end, people believe in the placebo effect. :-//
Actually ... the bandwidth was related to amplifier slew rate and "speed" errors in the past; a "20kHz" amplifier would be more and more inaccurate past a few kHz which would make even 1-2khz sounds sound bad (by damaging the higher harmonics). Sounds are not sinusoids; a sound with a 1kHz fundamental might even take 10kHz of bandwidth or more.
On top of that, mixing different sounds multiplies the necessary bandwidth. Mix a few sounds at 2-3kHz and their first 3 harmonics, you already need many tens of kHz of bandwidth.
No, an audio amplifier doesn't need to have any bandwidth beyond 20kHz to sound good. In fact, it's desirable to cut frequencies above 20kHz to reduce interference and protect tweeters.
The slew rate is important, but the full-power bandwidth doesn't need to extend all the way up to 20kHz, because music has a 1⁄f spectrum. In other words, an amplifier capable of an output voltage swing of 10V peak-to-peak, doesn't need to be able to do this at frequencies up to 20kHz, 2kHz is more than enough. Large voltage swings are due to bass, rather than treble.
-
Actually ... the bandwidth was related to amplifier slew rate and "speed" errors in the past; a "20kHz" amplifier would be more and more inaccurate past a few kHz which would make even 1-2khz sounds sound bad (by damaging the higher harmonics). Sounds are not sinusoids; a sound with a 1kHz fundamental might even take 10kHz of bandwidth or more.
On top of that, mixing different sounds multiplies the necessary bandwidth. Mix a few sounds at 2-3kHz and their first 3 harmonics, you already need many tens of kHz of bandwidth.
No, an audio amplifier doesn't need to have any bandwidth beyond 20kHz to sound good. In fact, it's desirable to cut frequencies above 20kHz to reduce interference and protect tweeters.
The slew rate is important, but the full-power bandwidth doesn't need to extend all the way up to 20kHz, because music has a 1⁄f spectrum. In other words, an amplifier capable of an output voltage swing of 10V peak-to-peak, doesn't need to be able to do this at frequencies up to 20kHz, 2kHz is more than enough. Large voltage swings are due to bass, rather than treble.
Do agree on some of your comments, but keep in mind the human ear has a non-linear reponse as well. Combine that with 1/f and you'll get a much flatter response up to 4kHz or so.
Also, I was referring to amplifier phase response rather than amplitude. An amp that has good amplitude response up to 20kHz will actually be quite poor over a few kHz in terms of accuracy.
-
What he described as a "power regenerator" looks to be almost as if it were an online UPS unit without batteries - where the output is a PWM generated low distortion sinewave that powers your product. Perhaps the term "regenerator" is common along the audiofolk, I don't know.
That Kikusui thing? Or are you referring to a different "he"?
It was referring to the original video. I did not watch the other one.
-
But but but ... :rant:
How perfect does it have to be anyway? In most cases the listener wasn't even at the recording or concert, so how do they even know what it's supposed to sound like. You can't say it's a "bad" or "good" reproduction unless you have compared it to the original in-situ recording. Even if it doesn't sound the same, who's to say it isn't enjoyable to listen to - or perhaps even better than the original might have sounded because it isn't exactly the same?
It's all subjective!
-
Their "Power Port" ( https://www.psaudio.com/products/powerport-classic/ (https://www.psaudio.com/products/powerport-classic/) ) isn't an outlandish ripoff at USD49. That's a Hubbell 20 Amp hospital outlet (HBL8300HG). Those are USD30 at my local industrial supplier. Nice outlets. Won't make your stereo sound any better.
EDIT: Is "hospital grade" worth 3x the price of a comparable heavy-duty outlet? I have a feeling that this is a case of adding a little extra value and then adding a lot of markup for that green dot. I'm a Hubbell fan. I use their commercial/industrial grade outlets and switches in the nest when a replacement is needed. The light switches have a nice "snap" to them.
-
Their "Power Port" ( https://www.psaudio.com/products/powerport-classic/ (https://www.psaudio.com/products/powerport-classic/) ) isn't an outlandish ripoff at USD49. That's a Hubbell 20 Amp hospital outlet (HBL8300HG). Those are USD30 at my local industrial supplier. Nice outlets. Won't make your stereo sound any better.
Well, they kinda are. Not in a local supplier, but a relatively unknown online shop (Amazon) sells Leviton's extra heavy duty 20A for US$10
https://www.amazon.com/Leviton-8300-T-125-Volt-Receptacle-Grounding/dp/B003ATRUM4/ref=sr_1_4?dchild=1&keywords=hospital+grade+receptacle&qid=1618592038&sr=8-4 (https://www.amazon.com/Leviton-8300-T-125-Volt-Receptacle-Grounding/dp/B003ATRUM4/ref=sr_1_4?dchild=1&keywords=hospital+grade+receptacle&qid=1618592038&sr=8-4)
-
Hubbell is a superior product to Leviton IMHO. I much prefer receptacles that have the face dished around the slots vs flat faced, it makes it much easier to get a plug in, especially when you're reaching down behind a sofa or cabinet or something to do it. Is it worth 3x the cost? That I don't know, I usually buy the spec grade Pass & Seymour Legrand receptacles, they're $2.79 at the local hardware store, very well made and have the same dished face.
-
Well, one can do this exercise all day, with similar models from Legrand and Eaton at around the same price and multiple choices of colors, etc. I personally have been using a mix of the three brands for 15 years without perceptible loss of functionality - although they were always used in a residential environment.