Isolation Transformer and Balanced Power versus PS Audio Regenerator

[Kingrex]

Are Balanced isolation transformers good for sound?

balanced isolation transformer change a parameter that you should consider.
Many amplifiers/dacs/... are sensitive to AC polarity, for example my TAD M700 have better sound when the AC polarity is positive, when I use balanced AC power the sound degrade .

you should first listen to your system at correct AC polarity then compare it to balanced power and check the result.

TAD do not like balance power of balanced isolation transformer

Balanced on the secondary can be a problem with equipment. They don't use it in recording studios. Torus is balanced on the primary and 120 hot, neutral 0 tied to ground on the secondary. This allows you to legally use a AFCI breaker in a residence. There are no AFCI that are listed and labeled to work on 60/60 volt. Maybe they work???? I have no idea.

If you are set on a large transformer to feed your factory, get a Controlled Power unit. They are very good. The triple insulated versions. I believe Torus is better, and Torus has the primary and secondary fused disconnects built into the unit. Way easier to mount and attach to the electrical system.

My single high output, 4.5 kva core, passes 745 amps. I don't have my RM20 at the moment to test. I can only assume the larger single output cores up to 12 kVA pass more, but the #10 AWG branch wire is going to be a limitation to power delivery.
Don't go thinking $8 is an improvement. Its way to analytical. And even Dan D'agostino told me his Relentless needs nothing larger than a #10 in 240 volt.

 

[Kingrex]

Would you please elaborate on exactly what sonic ways it was "way better than the wall"?




Would you please "unpack" this for us?

What was the measured electrical effect of the Everest?

What was the sonic effect of the Everest?

Sonically - Van Morrison Moondance. The acoustic guitar off to the left was much more crisp and clean. More fresh and alive. Through the wall it was compressed and sort of smeared into the rest of the song. The whole of the song through the wall was good, but its sort of closed in and all the instruments and vocals are more homogenous. Through the Torus all the parts are more distinct and separate. And have more vibrancy. The bass seems to have a little less weight. But its much tighter, faster and integrates into the midrange much better. When you go back to the wall, you sense the bass is possibly bloated and loose. Thats what you feel the weight is. Also, the whole is more relaxed and less ear fatigue.

When the subs were added. The bass got more controlled and focused. The bass was much better blended.

I have seen all brands of filter kickback noise onto the mains. I have no idea why they do this. Its very measurable.
And I did note, what I can see on my Fluke is not very high in resolution. These low order harmonics on the 3rd and 5th walk right through every filter I have ever tested. Including the isolation transformers. Its the higher level noise they block. Since non of the filters I have ever measured block the low order harmonics, I doubt what they kick back into the system is that damaging to other equipment on the line. Non the less. It is there and easy to see.

We never ran the Everest through the Torus. The Everest was always running the front end gear. I set the Torus between the monoblocks and subs. The rack is off to the side.

 

[dcathro]

Why not a second Equitech. Thats a fine isolation transformer. I would not mess with Topaz. Its not the same league. Issues. Topaz is maybe for modem, router, switch.

Hi Rex,

Can you please go into more detail as to what is wrong with the Topaz. I have a 5KVA one that cost me nothing.

Thanks

David

 

[adrianywu]

I have two CSE balanced isolation transformers from Japan for many years. I believe they were one of the first to produce such products. I use regenerative power for the turntable (for speed stability), and the transformers for everything else except the amplifier for my bass drivers. This is the combination I find best after years of experimentation. I suspect the power line noise is much higher frequency than what my bass drivers can reproduce, or perhaps my bass amp has better filtering. Plugging it into the transformer resulted in subtle but noticeable limitation in dynamics. No such problem for my midrange and tweeter amps, which are pure class A and low powered (15W and 10W). The result is far better through the transformers. For the source components, the preamp and the electronic crossover, the transformers is a must. All components in my system is balanced differential design. The transformer secondaries are also balanced 110/110V, and the power supply of all components, including the bass amp, are star grounded through the transformers. When I left the bass amp connected to the earth pin of the wall socket, there was a low level hum that disappeared when I grounded it through the transformer instead.

 

[Kingrex]

Hi Rex,

Can you please go into more detail as to what is wrong with the Topaz. I have a 5KVA one that cost me nothing.

Thanks

David

Thats kind of like saying, why doesn't my Schiit amp sound like my Dartzeel. Equitech, Torus and a few other isolation transformers are purpose built for audio. I have owned a few Topaz and a Triplite. The Topaz worked with my CJ Premier 140. It had bad transforner hum. As in, the power transformer saturated with DC and was audible in the next room. Same with my Rega Osiris. The Rega just sounded horrible on the Topaz. But it was much better with an Isotek Syncro. The CJ sounded flat and dull with the syncro, but was mostly unchanged with the Topaz. A hair loss of air and space. But the hum was gone and the loss very minimal. My front end sounded funny in the Topaz. Could not put my finger on it.

If you have it, and it works, use it. Not long ago I tied my Topaz through a circuit to my room. It did norhing for me. The Dartzeel did not like it.

It was Mike Lavigne that kept telling me, his power to all his gear sounded much better through the Equitech than the wall. I was skeptical. I bugged him for a year about it. You sure???? I had tried a lot of power conditioners and they were all hit and miss. I always found flaws. I was super hesitant. But I kept hearing about very high end systems such as Rhapsody in Dallas that use them. It made me investigate. Then I started to find most every recording studio and film production studio use isolation transformers. One of my Topaz came from such a place. A film editing studio. I reallly wanted to represent Equitech. But I could not get around the lack of AFCI. I like a large wall mount set in another room applied globally. With a rack mount this does not matter. And you can get a rack mount of either brand up to 10 or 12 kVA. But I don't like a 450 lb core spewing EMI all over the room. I'm ok with a small unit. But I have seen them need to be strategiy placed away from phono equipment and tube amps.

I don't have a technical breakdown of winding material, insulation, shielding etc that make them stand apart. I have been introduced to 2 other more esoteric hand wound units that might be fantastic. Never heard them. And they are expensive.

If you have a problem you know of. The problem stands out, and a Topaz works, use it. I used it with my CJ for a couple years. I was glad to have it.

 

[Kingrex]

and the power supply of all components, including the bass amp, are star grounded through the transformers. When I left the bass amp connected to the earth pin of the wall socket, there was a low level hum that disappeared when I grounded it through the transformer instead.

This is why I advocate for a large global unit. I fear the ground loop. I wonder if this is a unfortunate byproduct of the balanced power on the secondary side. I have not run into anyone having a hum issue with only part of the system in a rack mount Torus and the rest the wall or some other filter.

 

[Onepoint5]

- My amplifier psu capacity is 2800VA
- the full system psu capacity is 6400VA
- UPS/Inverter is linear at 1/3 or 1/4 max load

6400VA x 3 = 19200VA


I have seen FM Acoustics have a paper and desribe their high power amplifiers need over 60A linear current


FM wrote :
"The FM 1811 requires an ultra-high quality, ultra low-impedance mains supply to deliver its promise. A dedicated supply that can provide a minimum of 125A peak / 25A cont. at 120V (or 60A peak / 12.5A cont. at 230V) is required.

FM 1811 (500W RMS to 8 ohm)"


imagine UPS should deliver 60A linear , 60 x 3 = 180A

230v x 180A = 40kVA

I understand the ratings now why the UPS is the size it is.
3 phase input rectifiers in the UPS throw back 5th harmonic, that is 31% of the primary current draw. On a weak network like a house, this can be a problem for other appliances, like motors. The 5th harmonic is a reverse acting current that opposes torque the motor produces. If it ever gets to the speakers, it will counter the force in the speakers, but the line and load are usually uncoupled, except when the UPS is in bypass. Harmonics can also increase voltage on the neutral to ground which is another drama.

The transformer from Denmark is a better idea, since any harmonics from the UPS is gone. If not already ordered, I would specify a shield between the primary and secondary windings to avoid high volts and nasty transients coupled via capacitance to the secondary. This is a low cost option and very effective, needs to be ordered with the transformer, as it is wound on the primary.

Unbalanced versus balanced. There are plus and minus for both, with no rule dominating a decision, engineering or sound quality wise. An isolation transformer can cripple common mode noise, which is the goal, so either secondary philosophies are valid. It is important that some audio equipment have the correct polarity of line and neutral for protection systems and internal connections. To this end, the neutral connection at the transformer needs to have a low impedance connection to earth ground. This keeps the common mode noise under control and the ground to neutral voltage so close to zero.

 

[Amir]

Thank you One Point 5
Some 20KVA inverters/UPS works in single phase and over 20KVA most of them are three phase. I do not go for three phase systems.

I think the reason for bad sound of UPS/Inverter is not a simple subject and I do not know if there is any relation between higher THD or lower THD of those devices to the sound quality.
I have contacted some famous high end audio companies and recommended them to design a reference AC regenerator but non of them convinced to pay money for research and development in this area. High End is very small market and no audio company waste the money for these projects.

 

[Amir]

let me describe my two experience about AC quality.
the first experience was around 2001 and I wake up 4AM for reading university books (I had an exam) , the audio system was very entry level but the sound was unbelievable and I never never forget that. the tone was perfect and it was voice of god, very lovely and emotional sound.
in 2022 I also had similar experience just only for less than 15 minutes so in that short time I was in paradise .

I believe two things are the big secrets of high end audio , one is the speaker position and speaker/acoustics matching, second is the AC quality.

 

[Kingrex]

let me describe my two experience about AC quality.
the first experience was around 2001 and I wake up 4AM for reading university books (I had an exam) , the audio system was very entry level but the sound was unbelievable and I never never forget that. the tone was perfect and it was voice of god, very lovely and emotional sound.
in 2022 I also had similar experience just only for less than 15 minutes so in that short time I was in paradise .

I believe two things are the big secrets of high end audio , one is the speaker position and speaker/acoustics matching, second is the AC quality.

Its funny you say this. For so long I have heard people say the PS of any well designed piece of equipment should overcome any "Noise" from the utility line. Yet people still claim they hear a better sounding system at night and that some sort of filter works.

@Onepoint5 , why is this. How does all this noise impact the electronic performance of audio video equipment. How come the power supply is impacted by it.

 

[adrianywu]

This is why I advocate for a large global unit. I fear the ground loop. I wonder if this is a unfortunate byproduct of the balanced power on the secondary side. I have not run into anyone having a hum issue with only part of the system in a rack mount Torus and the rest the wall or some other filter.

I do star grounding for the signal in all my equipment, and this concept works too for the power supply. I have two transformers, one for the power amplifiers, and one for everything else. The grounds of the two transformers are tied together and grounded at one point in the wall socket.

 

[Ron Resnick]

Sonically - Van Morrison Moondance. The acoustic guitar off to the left was much more crisp and clean. More fresh and alive. Through the wall it was compressed and sort of smeared into the rest of the song. The whole of the song through the wall was good, but its sort of closed in and all the instruments and vocals are more homogenous. Through the Torus all the parts are more distinct and separate. And have more vibrancy. The bass seems to have a little less weight. But its much tighter, faster and integrates into the midrange much better. When you go back to the wall, you sense the bass is possibly bloated and loose. Thats what you feel the weight is. Also, the whole is more relaxed and less ear fatigue.

When the subs were added. The bass got more controlled and focused. The bass was much better

These are great and understandable descriptions! Thank you very much!

 

[Onepoint5]

Its funny you say this. For so long I have heard people say the PS of any well designed piece of equipment should overcome any "Noise" from the utility line. Yet people still claim they hear a better sounding system at night and that some sort of filter works.

@Onepoint5 , why is this. How does all this noise impact the electronic performance of audio video equipment. How come the power supply is impacted by it.

Harmonics cause the voltage between the earth (ground) and neutral to rise which is not great for audio equipment or computers for that matter. Less of this operates at night, so music sounds better. That's one reason, another has to do with temperature and velocity of sound through air which can be cooler and transmits 'easier', another story that's out there.

Here's a paper from Ametek on the NG voltages and their effects.

 

[Kris]

I don't believe a utility transformer is better at filtering noise than a Torus, Equitech or Controlled Power. Utility transformers are not built to be a noise filter. They probably do to some degree, but they are not designed with that intent in mind.

Torus has purpose built filtration.

NBT for the Rest of Us

NBT for the rest of us discussed NBT is simple terms.

www.toruspower.com

Lets explain it as you misunderstood I think.
usual scenario is
1. factory makes electric power , very clean and extreme high quality.
Yes. They make top quality energy.
They send to via 100 kv lines between the far regions.
In their distribution centers they drop it down from 100 kv to 15kv.
15kv line gets to your village / town
15 kv is distributed to different regions of your local area.
Tan you have multiple 15kv to 230 v transformers In your village,
That transformer supplys around 70 - 100 houses .
your home are just one of this 70 houses.
If so you SHARE the same line with all of them and whatever they connect to their wall is affecting your system. ( tons of Noise, poor power, passive power, harmonics, very noisy neutral !
Yes . You got it right. WE all create Poor power quality by equipement we use And we polute the good quality power.

My plan is not to use industial trafo to clean the durty power.
I want to have 1 house on my 15 kv to 230v trafo line .Not 100 homes but just 1.
So no noise , no harmonics and no poor power quality.

 

[Kris]

Here is an example …..
Do you really think this is worst than Torus Equitech ir whatever you had in mind ?

 

[Kingrex]

Lets explain it as you misunderstood I think.
usual scenario is
1. factory makes electric power , very clean and extreme high quality.
Yes. They make top quality energy.
They send to via 100 kv lines between the far regions.
In their distribution centers they drop it down from 100 kv to 15kv.
15kv line gets to your village / town
15 kv is distributed to different regions of your local area.
Tan you have multiple 15kv to 230 v transformers In your village,
That transformer supplys around 70 - 100 houses .
your home are just one of this 70 houses.
If so you SHARE the same line with all of them and whatever they connect to their wall is affecting your system. ( tons of Noise, poor power, passive power, harmonics, very noisy neutral !
Yes . You got it right. WE all create Poor power quality by equipement we use And we polute the good quality power.

My plan is not to use industial trafo to clean the durty power.
I want to have 1 house on my 15 kv to 230v trafo line .Not 100 homes but just 1.
So no noise , no harmonics and no poor power quality.

In the US, 1 transformer serves about 2 to 7 homes. Maybe its different in the country you reside in. A transformer serving 70 to 100 houses would be a massive transformer. The Arc potential would be so high, you would need industrial panelboards in each residence to withstand the potential energy applied during a dead fault.
I am not talking Arc as in Arc Fault Breaker. Arc and AFCI are 2 different things. AFCI is a very tiny flame between 2 contact points that slowly melts the device and starts a fire.
Arc is a single event of incredible force and energy that blows everything into tiny pieces and released a multi thousand degree fireball that vaporized everything around it. As well as plastering the walls with molten liquid copper and steel.

But we are both saying the same thing. The power from the street is not very clean. Its is audible between day and night. A good scope can measure the high frequency noise. I forget who gave this to me. I have read it a couple time. It could have been this thread. I find it interesting.
This is only 1 type of noise.

Power line noise

causes of power line noise and equipement to locate noise

www.w8ji.com

If someone were to live in a remote area with a single transformer to a single home. And you neighbors are acres away and don't have large drives operating wells or industrial equipment, you may not need an isolation transformer. You probably don't need a AQ5000 or Everest either. Maybe. If your near a cell tower, you might have all sorts of noise, but that noise is more likely to populate into your gear through the phono stage. Not the power cord to the wall.

 

[Kingrex]

Harmonics cause the voltage between the earth (ground) and neutral to rise which is not great for audio equipment or computers for that matter. Less of this operates at night, so music sounds better. That's one reason, another has to do with temperature and velocity of sound through air which can be cooler and transmits 'easier', another story that's out there.

Here's a paper from Ametek on the NG voltages and their effects.

Thats a very simplistic paper. Something I started addressing years ago. The potential between neutral and ground inside a panel was one of the first revelation I had when listening to the affects of power on audio. That as well as the aluminum in the panel. I try and chase the neutral and ground potential out to the end of the duplex. I have run 50 foot runs of #10 and had 0 mv between neutral and ground at the duplex. On other projects I have run 30 feet and had 30 mV to 60mV. Its frustrating. I think I am honing in on getting them all to 0. I have a few more test to perform.

The following is a cut and paste from Art Kelms Ground One. He is the only other person I know who goes as deep as I do. I look at noise, distribution and filtration very much as he does. We diverge in his use of steel encased branch and feeder runs. I like ENT. I highly doubt he has ever broken down a panelboard, cleaned and polished one like I do. But I don't really know. When I ship a panel, my copper compression lugs look like the attached. So do the bus bars and everything else where a wire lands.

By Art Kelm

After working over 40 years in the professional recording industry and the past 10 years of that involved in the high end A/V market, I have lost track of the number of times I have heard the term "clean power" used to describe someone's power system.

Whenever I raise the question "What do you mean by clean power?" I have never heard the same answer twice. It is like asking, "What is the best way to ground an audio and video system?" Everyone has their own interpretation.

The reality is, you can define "clean power" through testing and measurements. The same holds true for "grounding systems". I have compiled over 200 performance and noise readings of systems over the past 10 years, everything from industrial warehouse developments, to world-class production facilities in Los Angeles, condominiums in The Four Seasons hotel in San Francisco, to the upper east side of New York City and many points in between.

From my personal experience, I know that power and grounding is the heart of any electronic system. Keeping voltage distortion, current harmonic, normal mode noise and common mode noise to a minimum in a power distribution system, is ABSOLUTELY necessary for reliable operation. This is even more true for hard drive based audio and video systems. The unfortunate reality is that utility power and generator power is, simply put, not adequate for critical load applications.

THINKING ABOUT POWER IN A DIFFERENT WAY

In order to control power quality, one has to first look at the source of your power and how it is being distributed around your facility/system. For years sensitive electronic loads have been segregated from other equipment in the recording and post-production environment (sometimes not exactly correctly). I would suggest that we define and apply a minimum performance standard for all electrical systems that feed critical loads. I would also take this practice and include heavy technology driven homes. I have been involved in homes that have over $2,000,000.00 in sensitive equipment installed. Ideally all loads need to be divided into categories and isolated from one another. When engineering a new system, I would suggest that we then define loads into three basic categories.

PROPOSED CATEGORIES

1. Motor loads. (refrigeration, air conditioning and water pumps)
2. Lighting and convenience loads. (microwaves, coffee makers, dimming circuits, ect.)
3. Sensitive electronic loads. (control systems, audio and video equipment)

MOTOR LOADS:
If we were to put all of our motor loads on the same panel (or sub panels), we would be able to control the negative effects of spikes and dips that are common whenever a motor starts up (this is common when you see your lights dim when an air conditioning unit turns on). Having dedicated panels and circuits will eliminate this problem.

The next benefit to this approach allows us to add "Power Factor" correction to the system. All motors are inductive loads; the efficiency of the load is measured in PF (power factor). The goal is to achieve a number of 1 or 100% efficiency. When power factor correction is added to a system, the system is more efficient and leads to lower electrical bills. It also extends the life of the equipment. This solution can only be achieved when loads are isolated.

LIGHTING and CONVENIENCE LOADS:
These loads are generally not a problem. The exception is florescent light ballast and SCR dimmer circuits. Keeping these loads separate from other loads will make any negative effect much simpler to isolate and solutions simpler to engineer.

SENSITIVE ELECTRONIC LOADS:
These are the most critical loads to protect and condition. They require at a minimum the following.
1. A properly engineered and installed grounding system.
2. Electrostatic triple shielded isolation transformer, including RF filtering along with Spike and Surge Suppression.
3. Breaker panel with high quality bolt-in breakers, copper bus bars and isolated ground bus bar.
4. Additional high quality TVSS and filtering installed in panel board.
5. Stranded wire to feed receptacles.
6. Hospital grade receptacles.

Electrical wiring should be a minimum of 12 gauge for a 20 amp circuit. I prefer to up-gauge all wiring one size (that means #10) and make all the conductors the same gauge. My first choice is to run wiring in ridged or flex steel conduit; second choice is steel MC cable.

The next factor to consider is the length of wiring to the receptacle. I recommend that the power panel be located as close as possible to the main components of the system. This allows the impedance of the system to be as low possible. In studio and theater applications, this should be kept to less than 50 feet. For audiophile/stereo applications, wire should not exceed 20 feet.

The above recommendations should be the foundation of any system. Depending on your specific needs, additional power conditioning may be required. The most basic conditioning (after TVSS an RF filtering) is voltage regulation. This will be required if you are in an area that has reoccurring utility power fluctuations. Regulation can be accomplished a few ways. The most basic is a stepper transformer. These types of units monitor the output voltage of the transformer and changes taps on the primary of the transformer to adjust the output to the proper voltage.

The next option would be to use an inverter system. This unit's approach is to takes the incoming AC voltage and turns it to DC then back to AC again, generating a new low distortion sine wave. The third approach would be a "full on line" UPS system. This is basically an inverter system with batteries.

SETTING A NEW STANDARD FOR SYSTEM PERFORMANCE

I would like to now put some numbers to what I would be defining as a "Clean Power" system. (These measurements were taken with a Powervar Power Probe115 and Fluke 43 Power Analyzer)

SYSTEM WITH NO LOAD
1. Common mode noise less than 10mv
2. Normal mode noise less than 50mv
3. Voltage distortion less than 1.5%
4. Resistance to earth less than 5 Ohms

SYSTEM WITH LOAD
1. Common mode noise less than 50mv
2. Normal mode noise less than 150mv
3. Voltage distortion less than 1.5%
4. Resistance to earth less than 5 Ohms

The reason for the two different standards is reflected noise from the individual components' power supplies. One must consider that all power supplies have reflected noise. I refer to this as a component's "footprint". As with motors, there are solutions to help correct these issues.

I would consider a system achieving the above criteria a "Certified Ground One Power System".

In closing, I understand that my views and recommendations may seem a bit extreme to some, however, I believe that in this day and age of overly hyped power products, there is a need to establish a minimum standard for power system performance.

 

[Long Live Analog]

In the US, 1 transformer serves about 2 to 7 homes. Maybe its different in the country you reside in. A transformer serving 70 to 100 houses would be a massive transformer. The Arc potential would be so high, you would need industrial panelboards in each residence to withstand the potential energy applied during a dead fault.
I am not talking Arc as in Arc Fault Breaker. Arc and AFCI are 2 different things. AFCI is a very tiny flame between 2 contact points that slowly melts the device and starts a fire.
Arc is a single event of incredible force and energy that blows everything into tiny pieces and released a multi thousand degree fireball that vaporized everything around it. As well as plastering the walls with molten liquid copper and steel.

But we are both saying the same thing. The power from the street is not very clean. Its is audible between day and night. A good scope can measure the high frequency noise. I forget who gave this to me. I have read it a couple time. It could have been this thread. I find it interesting.
This is only 1 type of noise.

Power line noise

causes of power line noise and equipement to locate noise

www.w8ji.com

If someone were to live in a remote area with a single transformer to a single home. And you neighbors are acres away and don't have large drives operating wells or industrial equipment, you may not need an isolation transformer. You probably don't need a AQ5000 or Everest either. Maybe. If you’re near a cell tower, you might have all sorts of noise, but that noise is more likely to populate into your gear through the phono stage. Not the power cord to the wall.

Rex, this is a mirror image of my conditions. Yes, you’re correct about the phono stage(remember I contacted you about this awhile back and since have solved the problem.) We have a lot of thunderstorms and lightning here in the mid south so there’s whole house surge protection. I also plug everything in including amp(s) into Jim Weil’s Sound Application. I’m open to suggestions if this is not the best way.

 

[Mike Lavigne]

If someone were to live in a remote area with a single transformer to a single home. And you neighbors are acres away and don't have large drives operating wells or industrial equipment, you may not need an isolation transformer. You probably don't need a AQ5000 or Everest either. Maybe. If your near a cell tower, you might have all sorts of noise, but that noise is more likely to populate into your gear through the phono stage. Not the power cord to the wall.

i live in a remote area 30 miles east of the metro area, in a small community of multi-acre properties developed in the late 90's, so all up to date power grid, with a separate transformer for each property. further; my audio room is in a separate building than my home, where my dirty power for lights and HVAC is to one 100 amp panel, and my system power is with another 70 amp service to the Equi=tech 10WQ panel. so easy to compare an ideal conventional source to an isolation transformer.

you would think my dirty panel with all the advantages would be pretty close or equal to the Equi=tech. nope. the Equi=tech is a big step up in my system, and i can compare dirty and clean power with outlets in my room side by side.

 

[Kingrex]

Here is an example …..
Do you really think this is worst than Torus Equitech ir whatever you had in mind ?

Explain to me what proprietary technology or known shielding technology has been employed in that commercial transformer. What of it is designed to eliminate noise that impacts audio equipment. Its probably 0. Its is most likely a simple Buck and Boost transformer. Stepdown from 100,000 volts to 12,480 volts. Or 12,480 volt to 480 volt.

I do not work for Torus. I am only 1 of many reps. I do communicate with them and asked their chief technology officer for more info on NBT technology. They of course are not going to publish their proprietary technology and design.. Their exclusive narrow bandwidth technology (NBT) enables their transformers to operate as low-pass filters, allowing the 50Hz or 60Hz wave from the utility to pass while filtering out the higher frequencies where noise, interference and distortion reside. And they have 2 types of surge suppression. Series and MOV. They are in hundreds of recording studios around the world. Those studios do not use a commercial transformer to feed their recording equipment. Maybe the lights and general use outlets.

So, to be blunt, absolutely Yes. I believe a Torus isolation transformer is leaps ahead of a commercial transformer when it comes to filtering power that goes to sensitive amplifying equipment. I believe a part of the misconception of the performance value a good isolation transformer bring is from people using a commercial unit and not finding it satisfactory, then claiming all isolation transformers operate the same. I still have a Topaz 2.4kVA with .0005 pf. 120 volt to 120 volt. Suppose to be the one to get for audio. It came from a film editing studio. You want it. I will give it to you for a good price. Give me $200 and pay for the shipping. I spent $500 to buy it. Try it, then do what you can to sell it because its not going to make you happy. Its a boat anchor in my garage.