Isolation Transformer and Balanced Power versus PS Audio Regenerator

[Folsom]

I thought you previously said the inaudible nuisance interference noise blends with the fundimental 60 herts wave and creates a new distorted wave. Isn't that impactful to the ability of the equipment power supply to operate at its designed level of performance.

I'm not sure you're following along exactly. Noise comes with the 60hz AC yes, but the PSU filters 60hz into DC, but does not act the same on the higher frequency stuff.

If you have noise say at 3mhz, your speaker can't make that. So whether that "passes" over means little. But if it's parts of the process where gain/buffering occurs then it can change the sound and behavior of the parts.

 

[Kingrex]

I'm not sure you're following along exactly. Noise comes with the 60hz AC yes, but the PSU filters 60hz into DC, but does not act the same on the higher frequency stuff.

If you have noise say at 3mhz, your speaker can't make that. So whether that "passes" over means little. But if it's parts of the process where gain/buffering occurs then it can change the sound and behavior of the parts.

I believe it would be more accurate to say we are not understanding one another.

I was referring to RF type noise. I would not dismiss its impact.

My understanding is most filters pass 3rd and 5th harmonics noise from the utility or light, computers etc right through. Accept maybe a regenerator or battery powered filter.

Its high frequency RF noise, isolation transformers and other filters are very effective at blocking. That noise must be quite impactful as most filters have a large impact on sound.

 

[Folsom]

I believe it would be more accurate to say we are not understanding one another.

I was referring to RF type noise. I would not dismiss its impact.

My understanding is most filters pass 3rd and 5th harmonics noise from the utility or light, computers etc right through. Accept maybe a regenerator or battery powered filter.

Its high frequency RF noise, isolation transformers and other filters are very effective at blocking. That noise must be quite impactful as most filters have a large impact on sound.

RF is high frequency. It is khz high end range and mhz. It is not something different than what I am discussing.

Transformers can be lossy and that stops a fair bit of RF. Filters of various types tend to pass what is above their resonate frequency (which can be pretty high in RF range, so still good filter). Battery is often somewhat noisy but doesn’t pass AC stuff typically (depending on charger stuff). Regenerators IME may do almost nothing but make sure the main power AC wave is in good shape.

 

[Kingrex]

How is it a regenerator may do nothing.

 

[microstrip]

All the Ground Boxes I've seen offered to high end audio do not offer isolation. I'm convinced that if the audio equipment used in a system has a properly designed grounding scheme (rare in high end audio...) such boxes would offer no benefit whatsoever. That might be the case regardless.

A balanced line is typically a shield (pin 1 of the XLR) with the signal being on a twisted pair of wires within the shield. 4 wires (1 for the chassis connection) is not recommended. Take a look at that Rane article I linked in my prior post.

It is a pity that these "G xxxxx Boxes" are called "ground boxes" - it just adds confusion to a already ambiguous discussion. We have ground - the "earth connection" and ground , a shorthand for "ground plane" and sometimes people call the shield simply as "cable ground" . We did not need the bizarre boxes in this ground loop debate!

But we should remember that some of these Gxxxxx Boxes operate just by creating new ground loops! They are so different between them that IMHO we can't discuss them unless we specify a certain type and brand.

 

[Alrainbow]

So true but Also needed due to bad internal grounding topology and it’s varying from one device to another. So many issues would be addressed or resolved if we just had iso input to output on Devices I think we could agree on this part

 

[Alrainbow]

A regen does many things
but some people just don’t like them period
A Denali is a simple passive filter it’s not complex. It’s tuned to load by imp certain freq s.
now if this helps a given system great
a regen is far more complex
It regulates the voltage it also has passive filters
It helps dc offset , removes most common mode noise of one uses a Balanced iso to feed it even better. Now it’s not great for amps I feel where a Denali might fair better.
but try a Denali and compare to a regen on a good led panel with the cable box to let us know what one fairs better.

 

[_Alchemist_]

I have two dedicated lines coming direct from the meter.
I used to have a double furutech wall socket but I now terminated each line with a furutech fi 50 iec plug, like this I get rid of the wall socket and 2 power cords and I found it to be sonically better.
One line goes into my audionet humbolt and the other one goes into a nordost power distributor alimenting my dac, a farad, an ediscreation switch and a fiber box, and an additional switch. I plan on upgrading my dac, maybe into a rossini + clock or vivaldi 3 box.

The last couple of days I tested a Torus tot avr (with 3 plugs) and a Plixir cube 4 bac.
I also tested the devices with the EMI meter.
The Torus actually reduced quite well the noise from 700/1000 to >100. The plixir didn't change anything. (nor does the Nordost, but it is not advertised as such).

On listening tests, I found that the Torus was good in removing noise, there was absolutely no reduction in dynamics and speed (I tried plugging the amp).
Ultimately, I liked it best when my amp was on the wall and only the dac on the Torus.
I thought it brought a lot of weight, density and gravitas but at the expense of delicacy and elegance. The scale of voice and instruments was also a bit bigger than I would have liked. It is a bit more of 'in your face' presentation.
Overall, it is really not bad but not perfect.
It was doing a lot of things well but I think you would want a bit more elegance and naturalness in a high end system.
The plixir didn't do anything, I liked the nordost better.
Ultimately, I am still looking for a solution for power conditioning, I'd like to demo a few units, the plixir elite for one - not sure if I should get two 400 or one 1500? I've read contradicting reports on this ( I don't think I would plug my amp on it or should I?)
Anyone compared the plixir cube vs the elite? I hope they're very different.

Any other recommendations / feedback?

 

[LL21]

Hi...I have used the Torus AVR16 for a while now...really like it. And we drive it with a dedicated high-power special outlet (16amps...the one with the blue circular 3-round-prong plug). It drives the whole system and then into this Torus we decided to keep using the older Burmster 948 for sources and preamp only. Works well.

That said, if you wanted to go 'one level up' in terms of pure audiophile obsessions...I would imagine Paul Stratton at Z:Axis is your man. I would have gone with Z:Axis having found their power cables and umbilical and i2s cables to be fantastic. But his highest powered model does not quiet get us there with 235 Pure Class A mono amps plus a DD18+ sub.

SYMETRICA

Probably the biggest upgrade without changing the whole system? SYMETRICA by Z:Axis Audio Because life should be balanced.. Early Review of a pre production version here PRODUCT D…

zaxisaudio.com

Hope that is somewhat helpful.

 

[_Alchemist_]

Thank you, it is helpful . I checked this one out, and I wonder how it compares with plixir elite, both of them being symmetrical types of power supplies.

 

[Amir]

Sure you can use a regenerator to shield some of your components from the noisy components and appliances, wether it's a switching psu noise or noise from an AC motor, why I use one as mentioned above.

There are lots of widgets to clean AC and equipment noise both commercially and for high end including regenerators, some are effective at cleaning up the mains and some less so but all the ones I tried have a direct effect the sound in all kinds of ways and mostly negative including over a dozen regenerators and several generators. Yes according to my ideals of a pure natural musical sound. It is also a given that if the system has a lot of distortion and or coloration the negative sonic effects of these widgets will go unnoticed.

Why doesn't a cleaner regenerated supply sound better than the noisier dirtier mains is the question, I wish it was simple and I had all the answers but I don't, it's a mystery like why do power cords and even plugs and outlets effect the sound. I'm fine with you calling all this a myth, there are other posts in this thread with different views pick whichever you like and run with it.

david

wil, I use regenerators for two reasons, one having so many different tts with different voltages and frequencies is a must but other reason that I would use one anyway is that motors and controllers generate noise plugging them into a regenerator stops the noise from getting into the mains. Never for any component that creates, passes or amplifies a signal.

I don't have a technical explanation nor have I heard a convincing one from anyone as to why some high end systems are so sensitive to even a change in the IEC of the power cord. What I know is that the numbers you quoted mean very little and nothing to do with resulting sound quality. Just to give you an example I have several different grounding schemes in place for the listening room and the one with highest resistance by far is the one that sounds best, go figure. IME any type of mains conditioning or regenerating device I've come across changes the sound of a system by adding a distinct signature/distortion/coloration or whatever you want to call it vs your average mains quality even without dedicated lines and are totally ineffective when the mains is really bad, the congestion and distortion caused by very bad mains will come through no matter what product I use. These AC management components or at least the so called better ones including high end power cords are all designed to do something to the sound and change different parameters, the problem is that you can't regulate how much or at what frequency, they run wide open and paint over everything with the same brush so every recording is covered with that coloration and presentation. This is very obvious if one has a system with enough resolution to play back different recordings hearing differences of each, both good and bad. I know I'm gong to get slack for this but you wont have real resolution using many of the high end power cords, cat litter boxes, some tweaks, footers, racks, etc. and certainly not a computer or tablet as source, in these cases you're just equalizing, adding or replacing one coloration/distortion with a new one. Look at this devices as capacitors.

david

Disclaimer, I'm expressing views based on my own values for a high end system and how it should sound.

100% agree

Thank you

 

[Amir]

Back in the day they had no ground at all, and everything was ok. In some ways requirements for safety ground is one of the worst things to happen to studios. They have to deploy all these techniques to stop a lot of the problems having safety ground creates. They may have had a little more noise in some studios, but others had relatively none from loop problems - it wasn’t abnormal for people not to know why as even today it can be confusing.

Lowering ground resistance increases common mode noise up to the point of bonding the PSU to the safety ground (if it does). It reduces some across interconnects, but not too much because the shield resistance path can be less, too, because of the lower resistance connections. If there was no safety ground there wouldn’t be any common mode noise. But RF pickup is lower - sadly it probably doesn’t matter unless they’re close to a tower.

TAD Reference CD/Pre/Power are designed to be disconnected from earth wire (floated chassis ground) and they have better sound. you are right about RF pickup but treating the listening room like fadary cage will decrease RF over 80db

 

[ICUToo]

I use Plixir's 3000 BAC Elite , and I plug everything in, including the Humboldt. At first, I kept my subs off, but the difference was small. When I included them, it sounded better- lower noise floor, more legible.
I hear NO restriction, and the whole system sounds better, more like late-night listening even during the day.
That said, it gets even better at night, maybe that's less ambient noise?

 

[Atmasphere]

That said, it gets even better at night, maybe that's less ambient noise?

If the time of day affects how the system sounds, its a good bet your 'power conditioner' isn't doing much. The reason it might sound better at night is because the line might be lower noise and higher voltage. A good power conditioner should be able to do that any time of the day.

 

[ICUToo]

If the time of day affects how the system sounds, its a good bet your 'power conditioner' isn't doing much. The reason it might sound better at night is because the line might be lower noise and higher voltage. A good power conditioner should be able to do that any time of the day.

No, the conditioner is doing a good job, day listening now sounds much like night listening.
Night time is just quieter in terms of ambient sounds from other rooms / houses / roads etc

 

[_Alchemist_]

Has anyone tester the plixir elite with the EMI meter?
I just tested the Cube, not the elite.
The Torus was doing a decent job.

 

[Frankie67]

Just ordered a Plixir 3000 BAC Élite, which will be connected via Furutech NCF plugs to my already installed Doepke circuit breaker. Looking forward to it!

 

[Onepoint5]

How is it a regenerator may do nothing.

A regenerator, let's call it an inverter, cause that's what is really is, may do something and it's usually switching noise around the 1kHz-3kHz mark. This noise is created by the capacitive coupling between the case of the IGBT/FET/Bipolar transistor and the case, usually a heatsink. Either you float the heatsink or the output somehow above ground to stop common mode noise, or there's an isolation transformer on the output to kill common mode noise.
Some UPS have a transformer, many do not, at 1.5kVA to 3kVA as encountered in audio systems, probably not fitted as they are heavy and expensive. That switching noise is conducted emissions, you could filter that out, since it's a fixed frequency. The trade off is that it's not quite fixed frequency as the output voltage needs regulation due to load imposts, so the switching frequency will need to be varied and a broader band filter will need to be designed.
I thought about a UPS over a dedicated line, but the noise both conductive and acoustic problems would cause more headaches. In addition, the best output THD for a UPS is best 5%, the raw THD at my house from the street is less than 2%, so don't need further distortion.

The use of isolation transformers like the Topaz are simple, yet very effective devices, especially in balanced output. One could argue that an isolation transformer robs dynamics from the music, but this is dependant on the cabling between the transformer and the audio system being of sufficient size to cope with the 25% duty cycle that power amps draw, and the output impedance of the secondary of the transformer should provide sufficient voltage regulation to avoid excessive voltage drops when the rectifiers start to kick in current at about 60deg (something). This is a matter of dimensioning the transformer correctly in the first place.

 

[Amir]

I have used high quality UPS like ABB switzerland and also low power audiophile AC regenerators.

This is ABB 20KVA ups :




The sound of all UPS and audiophile AC regenerators were not good except purepower 3000+.

I also used low power isolation transformer the result was not good and I am looking for buying 20KVA isolation transformer from denmark.

 

[Kingrex]

A regenerator, let's call it an inverter, cause that's what is really is, may do something and it's usually switching noise around the 1kHz-3kHz mark. This noise is created by the capacitive coupling between the case of the IGBT/FET/Bipolar transistor and the case, usually a heatsink. Either you float the heatsink or the output somehow above ground to stop common mode noise, or there's an isolation transformer on the output to kill common mode noise.
Some UPS have a transformer, many do not, at 1.5kVA to 3kVA as encountered in audio systems, probably not fitted as they are heavy and expensive. That switching noise is conducted emissions, you could filter that out, since it's a fixed frequency. The trade off is that it's not quite fixed frequency as the output voltage needs regulation due to load imposts, so the switching frequency will need to be varied and a broader band filter will need to be designed.
I thought about a UPS over a dedicated line, but the noise both conductive and acoustic problems would cause more headaches. In addition, the best output THD for a UPS is best 5%, the raw THD at my house from the street is less than 2%, so don't need further distortion.

The use of isolation transformers like the Topaz are simple, yet very effective devices, especially in balanced output. One could argue that an isolation transformer robs dynamics from the music, but this is dependant on the cabling between the transformer and the audio system being of sufficient size to cope with the 25% duty cycle that power amps draw, and the output impedance of the secondary of the transformer should provide sufficient voltage regulation to avoid excessive voltage drops when the rectifiers start to kick in current at about 60deg (something). This is a matter of dimensioning the transformer correctly in the first place.

Nice post. Your technical understanding of UPS and regenerators is much deeper than mine. Your conclusions are the same. I have been told only the Pure power 1500 unit sounded good. Who knows. I have heard a Stromtank on 2 systems on the front end. I don't know I would say it damaged anything. Both systems were well tuned and performes at a high level. I was not afforded an opportunity to listen through the unit and wall to compare. I was not afforded the opportunity to hear it compared to the Equitech 1500 rack mount sitting in a corner unused.