Fools and their money are easily parted... I'm no audio expert but isn't this what an digital-to-analog converter is used for in the audio industry? This just seems like overkill with extremely diminishing returns (if any).
No. A digital to analog converter (DAC) is used to convert digital audio signals (e.g. on a CD or computer) to analog ones for driving amplifiers and speakers. You're perhaps thinking of a double-conversion UPS or power conditioner, which converts electricity to DC, filters it, charges a battery (in the case of a UPS), then converts it back to AC to power your devices.
Ok thanks for clarifying. I was thinking of a feature on a motherboard I recently purchased:
"USB DAC-UP provides clean, noise-free power delivery to your Digital-to-Analog Converter. DACs can be sensitive to fluctuations in power from the other USB ports, which is why USB DAC-UP takes advantage of an isolated power source that minimizes potential fluctuations and ensures the best audio experience possible."
I've also had to use a 5v step up converter to provide a filtered power source for the camera on my FPV drone I built. I can see why an Audiophile would want filtered voltage supply if they had money to burn I guess.
Yeah, the isolation in this Japanese case is similar in intent to the isolation your motherboard advertises, but on a much larger scale. It's the isolation that matters. Every mobo has a DAC if it has audio, but not every mobo has an isolated power supply for the DAC.
You're laughing, but an arts building I worked in had a separate electrical system (color-coded outlets) for A/V equipment in its performance spaces. I'm hazy on the details, but professional systems integrators apparently do believe that some components are sensitive to noise in the electrical supply, and it is useful to separate them from the rest of the electrical devices in a large building.
Google led me to a whitepaper [0] which indicates that the A/V power system's interesting characteristic was probably that its ground is bonded to building ground at exactly one point. Apparently in this design it's undesirable for an A/V system device to accidentally connect to the main building ground or actual "earth," which jives with my experience that a component accidentally plugged into a regular outlet created an unbearable hum in the audio signal (i.e. the grounds were substantially different).
Because some of these venues also run lighting rigs in the order of magnitude of 100KW and probably don't have the space/money/expertise to install a UPS with that power capacity.
A single loudspeaker in a line array can draw up to 24A at 240V [0]. Even a very small rig of 6 speakers would require over 30kw. A 50kw UPS [1] can be purchases for a very affordable $25,000 in 2016 [2]. When building a performance art venue in 1960 or today, a technical ground is a much more suitable option than a UPS.
This is a valid concern - due to not only differing grounds but also the transients/hf noise created from ten- and hundred-KW lighting dimmer systems, audio and lighting power must be kept seperate
In recording studios, you will sometimes find 'technical power' which is delivered on balanced wiring from an isolation transformer. This is rarely seen outside of radio and television studios, though. Many performing arts spaces have a simpler version, of dedicated outlets for power amplifiers that are on an isolation transformer if anything, but usually just a separate run to the main panel - this is mostly just to avoid the ground loop problem, as you mentioned, as well as to avoid certain kinds of noise that amplifiers might pick up.
I doubt that the isolation gained from having one's own pole transformer is any better than what an isolation transformer gets you. You'd still be subject to any noise or trouble in the distribution-level wiring, and at the end of the day I think most of the problematic electrical issues you could have in audio are going to originate in your own house anyway. It's probably much better bang for your buck to put your audio equipment on a nearby isolation transformer, which are not necessarily cheap but certainly don't run in the five figures (or at least not until they get very large).
But with these kinds of audiophiles, bang for your buck isn't what it's about. Having known some audiophile extremists like this, at least in my limited experience, it's just a status symbol.
Edit: As an anecdote about amp noise, while lighting is a pretty big issue most permanent venues have their lighting well-segregated into a central dimmer rack anyway. The most notable time I got an angry noise out of an amplifier is when I accidentally plugged a hydraulic manlift into a poorly labelled amp rack socket. When I went to ascend, the noise from the house speakers made me just about jump out of my skin, to the great amusement of my coworkers.
Rarely seen outside of studios and hospitals. I guess people will point and laugh at this but they probably aren't laughing at FDA device safety rules.
"Technical power" in your house is pretty much against all building codes. You need color-coded outlets and warning signs on all outlets and on the entry doors, in a commercial setting where the code allows such wiring. On the other hand, wiring your amps up this way has a certain economy to it; it's actually pretty cheap and effectively solves the problem for a lot less than the $10k (plus ongoing monthly costs of extra power service) cited in this article.
Note that this is specifically for a 120V system where instead of a single hot and a neutral, you have two hot wires, each at 60V to ground and running 180 degrees out of phase. Similar to how 240V receptacles are wired in residential.
For commercial buildings, the common layout to run a "computer" circuit with a dedicated ground and neutral, while sharing them between multiple other circuits for general loads. There are a lot of variations on this sort "isolated circuit" setup, and it's pretty much standard practice. I couldn't say how much most computers and other loads actually care that they share a noisy neutral, but I did have one personal experience with a building where an Xbox 360 couldn't get past a game's first loading screen because the power was so dirty.
I'd think the reason it's against the NEC is to avoid surprises during infrequent residential servicing.
You could do the same thing outside of the wall though. But if you're tying the grounds together and feeding equipment that has its own transformer, I don't see much of a point.
I'd also think the FDA safety rules would require it for its failure modes, not power quality. Actual patient isolation is taken care of by the devices themselves.
I have personally encountered difficulties in grounding and bonding when different portions of a distributed instrumentation system used "local" grounds on the nearest aircraft structural member as their ground reference. The ground potential from one place to another on the structure of an aircraft in flight can vary wildly. This caused no end of problems (sudden shifts in parameters, dead power supplies, etc).
For performance critical applications, minimize the number of grounds.
Big ass -48vdc battery banks, float charge controllers and precision sine wave inverters are a solved problem. If it's good enough for a $235,000 Infinera DWDM platform...
Floor space is severely limited in Japanese homes however. I'm not an expert but what you describe sounds large. Most have a little bit of space at least on one side of the house however due to Japanese building code, so your own pole might actually be more practical ;-).
The funny thing is, all audio circuits run on DC power, thus necessitating the inclusion of an AC/DC converter in every piece of hifi equipment on the planet.
So if you go to the trouble of setting up a battery bank, it would make sense (both financial and sound quality) to ditch the sine wave inverter and hack your equipment to accept DC directly.
You know what's interesting to me? Almost everything runs on DC these days. Lights are solid state, just about all electronics have a power supply that converts to DC, even a lot of (admittedly high end) home gadgets use brushless DC motors. The only AC devices I can count in a normal home are the big appliances like electric stoves, HVAC fans, etc. I wonder why there has not been more progress in a DC home distribution standard. Especially because efficiency generally increases with load, all of those little wall warts are less efficient than one big AC to DC converter.
because there's no single DC voltage that all devices use, so you'd end up with homes wired with 48VDC and many power brick/wall-wart dc-dc converters to obtain 24VDC, 19VDC, 17.5VDC, 12VDC, 5VDC, etc.
and the cable gauge would need to be incredibly thick to avoid significant losses, DC does not go very far distances well at all. Be ready to pay for #2 gauge copper in your walls instead of 14ga.
unrelated, but does anyone know how does a websearch of the article works around and displays the aticle on the wsj site while clicking on the link takes the user to the "subscribed aricle" page?
I have been to a house in Dallas that has a separate 110v utility pole to feed a system that costs 4x the house it resides in. The center piece is a set of focal grand Utopias em (160k retail) each fed by custom made 750w mono tube amps. He has a studer 8 track reel to reel and multiple technics sp-10 and sp-15 turntables with 2 arms each and multiple 5 figure hand made cartridges.
This is a friend of my uncle. He has a record collection that DJ premier would envy. I spent 3 hours just listening to music on what was probably the best stereo I've ever heard and will ever hear. I don't know what was the halo effect and what was real but it sounded incredible. That said, the music is still the music. I am an amateur recording artist for about 20 years. I've had brushes with major releases and recorded in big studios. here is my point I think it's slightly ironic to see people spend so much money to listen to records that are sometimes recorded on awful gear or made to sound distorted on purpose.
That's all 60Hz AC coming from the power company, and the only thing connected to it are the step-down transformers en-route to your house. Not much there to generate noise.
Try the following experiment: Go through your house and count how many "wall warts" you have plugged in.
Two decades ago, 100% of those were simple, inefficient, low-noise, transformer+rectifier+caps AC/DC converters.
Now? 100% of them are high-efficiency DC/DC switching power supplies. These power supplies create switching spikes -- a kind of noise which is extremely high frequency and has a nasty habit of propagating places you don't want them to go. The thinking which leads to having your own power pole installed is that some remnant of these spikes are propagating into your house from all of your neighbors.
Having your own power pole installed is one way to address that, but I'd think that $10k would buy you one hell of a 60hz band-pass filter...
There was me thinking running a dedicated spur from consumer unit to hifi, when we rewired, was overkill. Did a very good job of isolating from random clicks/pops compared to being on the house ring though. Fails at being audiophile though, it cost about £20 at most, if you include the new sockets.
Could any electrical engineers comment on this story? How would you measure whether current is "dirty"? What quantifiable factors would you want to examine to figure out if this improvement is real or B/S?
Is a personal transformer and electrical utility pole is likely to perform better than whatever typical solution one might employ for power conditioning, like a power supply? How would a personal transformer help with "dirty" electricity? (Does it prevent noise somehow from other devices on the same transformer?)
It seems like there could be noise issues with currents that a transformer wouldn't help with though. For example, I had understood that some power plants vary their operating frequency slightly over the course of the day, perhaps dependent on the speed that flywheel or generator is turning. So the frequency of the AC current might very slightly change. A personal transformer wouldn't help with this, would it?
If something as precise as our TVs and computer processors can run connected to a power supply to regular AC power, then it seems like stereo equipment should be able to too. Why doesn't a regular power supply compensate for this?
You can graph the voltage. If it's close to sine wave, it's "clean". If it's a mess, it's "dirty". In more precise terms, you can check how much power is in frequencies further away from the main one (50 / 60 Hz depending where you live).
As for the difference in the audio output, it will be very different between different quality audio equipment. On the good side they may go as far as smoothing out the input power internally. On the opposite side, you've got cheap old vinyl players which output a constant 50Hz + harmonics buzz in the output, even with perfectly clean power supply.
If mains noise gets into an audio system, it's because of crappy (eg cheap) design. Any Audio designer should assume that the mains is very, very noisy.
And if it does happen, a simple noise filter should fix it. Which would mean that the amplifier lacks even basic filtering.
There are specs which the electrical supplier must comply with. If you complain of dirty power, the supplier will fit a pen recorder (or modern equivalent) for a week or so to check if it's true.
56 comments
[ 2.7 ms ] story [ 112 ms ] thread"USB DAC-UP provides clean, noise-free power delivery to your Digital-to-Analog Converter. DACs can be sensitive to fluctuations in power from the other USB ports, which is why USB DAC-UP takes advantage of an isolated power source that minimizes potential fluctuations and ensures the best audio experience possible."
I've also had to use a 5v step up converter to provide a filtered power source for the camera on my FPV drone I built. I can see why an Audiophile would want filtered voltage supply if they had money to burn I guess.
In the case of the article, $10k would buy you an unbelievably effective 60hz band-pass filter...
Google led me to a whitepaper [0] which indicates that the A/V power system's interesting characteristic was probably that its ground is bonded to building ground at exactly one point. Apparently in this design it's undesirable for an A/V system device to accidentally connect to the main building ground or actual "earth," which jives with my experience that a component accidentally plugged into a regular outlet created an unbearable hum in the audio signal (i.e. the grounds were substantially different).
[0] http://www.surgex.com/pdf/PowerGround.pdf
With a dual-conversion UPS, I don't believe that there'll be any noise from the power grid.
http://bobbyowsinski.blogspot.com/2012/05/485-volume-knob.ht...
I would hope that any good quality amp would filter the incoming power, though.
[0]: http://www.meyersound.com/sites/default/files/leo-m_ds_a2.pd...
[1]: http://powerquality.eaton.com/Products-services/Backup-Power...
[2]: https://store.fgcupssystems.com/products/eaton-93pm-50kw-480...
I doubt that the isolation gained from having one's own pole transformer is any better than what an isolation transformer gets you. You'd still be subject to any noise or trouble in the distribution-level wiring, and at the end of the day I think most of the problematic electrical issues you could have in audio are going to originate in your own house anyway. It's probably much better bang for your buck to put your audio equipment on a nearby isolation transformer, which are not necessarily cheap but certainly don't run in the five figures (or at least not until they get very large).
But with these kinds of audiophiles, bang for your buck isn't what it's about. Having known some audiophile extremists like this, at least in my limited experience, it's just a status symbol.
Edit: As an anecdote about amp noise, while lighting is a pretty big issue most permanent venues have their lighting well-segregated into a central dimmer rack anyway. The most notable time I got an angry noise out of an amplifier is when I accidentally plugged a hydraulic manlift into a poorly labelled amp rack socket. When I went to ascend, the noise from the house speakers made me just about jump out of my skin, to the great amusement of my coworkers.
"Technical power" in your house is pretty much against all building codes. You need color-coded outlets and warning signs on all outlets and on the entry doors, in a commercial setting where the code allows such wiring. On the other hand, wiring your amps up this way has a certain economy to it; it's actually pretty cheap and effectively solves the problem for a lot less than the $10k (plus ongoing monthly costs of extra power service) cited in this article.
Edit: NEC here: http://www.equitech.com/support/647.html
For commercial buildings, the common layout to run a "computer" circuit with a dedicated ground and neutral, while sharing them between multiple other circuits for general loads. There are a lot of variations on this sort "isolated circuit" setup, and it's pretty much standard practice. I couldn't say how much most computers and other loads actually care that they share a noisy neutral, but I did have one personal experience with a building where an Xbox 360 couldn't get past a game's first loading screen because the power was so dirty.
For some examples, see the options listed on page 2 and wiring diagrams on page 3 here: http://www.electri-cable.com/v/vspfiles/download/Electri-Pak...
You could do the same thing outside of the wall though. But if you're tying the grounds together and feeding equipment that has its own transformer, I don't see much of a point.
I'd also think the FDA safety rules would require it for its failure modes, not power quality. Actual patient isolation is taken care of by the devices themselves.
For performance critical applications, minimize the number of grounds.
So if you go to the trouble of setting up a battery bank, it would make sense (both financial and sound quality) to ditch the sine wave inverter and hack your equipment to accept DC directly.
Take a look at this amplifier: http://www.allegrosound.com/Accuphase_P-400.jpg
Those giant round things and square things along the sides? Totally unnecessary if you already have a (DC) battery bank...
and the cable gauge would need to be incredibly thick to avoid significant losses, DC does not go very far distances well at all. Be ready to pay for #2 gauge copper in your walls instead of 14ga.
Seems like it would make more sense to just buy a higher-end inverter for an off-grid solar setup; and charge the batteries when he's not using it.
Maybe buying, housing, and maintaining a bunch of electrical equipment awkwardly in your home isn't worth the difference to many.
This is a friend of my uncle. He has a record collection that DJ premier would envy. I spent 3 hours just listening to music on what was probably the best stereo I've ever heard and will ever hear. I don't know what was the halo effect and what was real but it sounded incredible. That said, the music is still the music. I am an amateur recording artist for about 20 years. I've had brushes with major releases and recorded in big studios. here is my point I think it's slightly ironic to see people spend so much money to listen to records that are sometimes recorded on awful gear or made to sound distorted on purpose.
There'd be nice big warnings around the perimeter about how "If lights are flashing, not a dance party, get out, halon is discharging"
I wonder if any of these audiophiles have ever considered their own private power plant.
Try the following experiment: Go through your house and count how many "wall warts" you have plugged in.
Two decades ago, 100% of those were simple, inefficient, low-noise, transformer+rectifier+caps AC/DC converters.
Now? 100% of them are high-efficiency DC/DC switching power supplies. These power supplies create switching spikes -- a kind of noise which is extremely high frequency and has a nasty habit of propagating places you don't want them to go. The thinking which leads to having your own power pole installed is that some remnant of these spikes are propagating into your house from all of your neighbors.
Having your own power pole installed is one way to address that, but I'd think that $10k would buy you one hell of a 60hz band-pass filter...
Is a personal transformer and electrical utility pole is likely to perform better than whatever typical solution one might employ for power conditioning, like a power supply? How would a personal transformer help with "dirty" electricity? (Does it prevent noise somehow from other devices on the same transformer?)
It seems like there could be noise issues with currents that a transformer wouldn't help with though. For example, I had understood that some power plants vary their operating frequency slightly over the course of the day, perhaps dependent on the speed that flywheel or generator is turning. So the frequency of the AC current might very slightly change. A personal transformer wouldn't help with this, would it?
If something as precise as our TVs and computer processors can run connected to a power supply to regular AC power, then it seems like stereo equipment should be able to too. Why doesn't a regular power supply compensate for this?
http://superuser.com/a/182004/11814
You can graph the voltage. If it's close to sine wave, it's "clean". If it's a mess, it's "dirty". In more precise terms, you can check how much power is in frequencies further away from the main one (50 / 60 Hz depending where you live).
As for the difference in the audio output, it will be very different between different quality audio equipment. On the good side they may go as far as smoothing out the input power internally. On the opposite side, you've got cheap old vinyl players which output a constant 50Hz + harmonics buzz in the output, even with perfectly clean power supply.
And if it does happen, a simple noise filter should fix it. Which would mean that the amplifier lacks even basic filtering.
There are specs which the electrical supplier must comply with. If you complain of dirty power, the supplier will fit a pen recorder (or modern equivalent) for a week or so to check if it's true.