MGE Ultra-Isolation Noise Transformer, 5 KVA MODEL 91005-31T

ddk

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May 18, 2013
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of course he can't understand cause and effect that way. has he lived with all transformers? of course not. he has a right to his own opinions about the subject.

for me i can switch back and forth from Equi=tech to dirty power (those outlets are right next to my Equi=tech transformer outlets) and hear for myself what is the difference. and his view is not what i hear.

You're confirming that there's a clear audible signature from the transformer, aren't you? You prefer it over what's coming out of your walls and I never suggested anything different.

No, I haven't heard every transformer but I've heard quite a few and lived with enough of them to find a commonality in their affects. Could there be one that defies the rest? Maybe, but I haven't found it.

david

PS Equitech is one that I'm familiar with.
 
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Mike Lavigne

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Apr 25, 2010
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You're confirming that there's a clear audible signature from the transformer, aren't you? You prefer it over what's coming out of your walls and I never suggested anything different.

No, I haven't heard every transformer but I've heard quite a few and lived with enough of them to find a commonality in their affects. Could there be one that defies the rest? Maybe, but I haven't found it.

david

PS Equitech is one that I'm familiar with.

to me a 'signature' is a coloration over the music, something added or filtered out in the musical signal. a sameness....at worst a dullness.

i hear the opposite of that with the Equi=tech in contrast with my dirty power. i hear more harmonic complexity and life....much more micro-dynamics...and more dynamic contrasts....with the lower noise floor.

i'll point out that all Equi=tech installations are not created equal. ground rod schemes, the type of copper selected, the size of the transformer, RFI fitering used......can all vary. then you have the GFI on each circuit that, if left in stock per code, can reduce transparency. i had those replaced with a straight wire. then there are the duplex outlets and even the outlet covers and how the wires are attached.

again; my proof of performance were the other outlets from my regular panel sitting there to easily A/B and hear for myself.

PS; i prefer simple power cords too. they should do as little as possible.
 

ddk

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May 18, 2013
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to me a 'signature' is a coloration over the music, something added or filtered out in the musical signal. a sameness....at worst a dullness.

Everything has a 'signature/coloration' to various degrees, there's no getting away from that. The type of 'signature/coloration' and the amount of intrusiveness might be different but its always there.

i hear the opposite of that with the Equi=tech in contrast with my dirty power. i hear more harmonic complexity and life....much more micro-dynamics...and more dynamic contrasts....with the lower noise floor.

I never made a quality judgement on your sound, just that I heard the transformer 'signature/coloration' in your room. I also have a transformer in my system and I hear the same 'signature/coloration' affect the harmonics when its plugged in.

i'll point out that all Equi=tech installations are not created equal. ground rod schemes, the type of copper selected, the size of the transformer, RFI fitering used......can all vary. then you have the GFI on each circuit that, if left in stock per code, can reduce transparency. i had those replaced with a straight wire. then there are the duplex outlets and even the outlet covers and how the wires are attached.

Sure, every installation is different and your installation will have its own 'signature/coloration' as will mine, but that's separate from the 'signature/coloration' of the transformer, they do what they do.

again; my proof of performance were the other outlets from my regular panel sitting there to easily A/B and hear for myself.

PS; i prefer simple power cords too. they should do as little as possible.

Performance doesn't mean lack of 'signature/coloration', just difference. Also from what you're telling me you're not comparing apples with transformer to apples without the trans, you're comparing completely different species of fruit.

david
 

TP1

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Apr 2, 2014
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Hang on a minute! So is the proposition that removing common mode noise ( the greatest pollutant present in the electrical grid in my experience) and DC ( transformers cannot pass DC) from the mains power line = sonic coloration? If so we had better inform many of the worlds leading recording studios and broadcasters of their folly of using balanced power supplies with their equipment.
 

ddk

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May 18, 2013
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This is how I install and test the larger units, that plug from the outlet is going directly to my dedicated panel feeding the system. Everything remains the same, the difference in 'performance' is only from the transformer. I also have the option to completely disconnect the transformer from all wiring and turn it off, there's even a noticeable difference in the 'performance', 'sound' with it on or off even when bypassed. The rails system allows me easier exchanges between different units, this is the current one that I'm testing out now.


Transformer-Installation.jpg


david
 

Occam

[Industry Expert]
Dec 15, 2010
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Hang on a minute! So is the proposition that removing common mode noise ( the greatest pollutant present in the electrical grid in my experience) and DC ( transformers cannot pass DC) from the mains power line = sonic coloration?

I hung on for a full 3 minutes. Common mode noise attenuation and not passing DC are characteristics for any galvanicly isolated transformer, whether a typical isolation transformer, or a balanced/technical power transformer. The sole additional benefit of balanced/technical power is the (theoretical and lesser, actual) leakage current to ground cancellation.

Additionally, common mode mains noise attenuation is simply implemented with minimally current limiting common mode chokes and binocular cores. Minimizing dc on a mains is also straightforwardly accomplished without risking saturation on a transformer. FWIW

-Paul
 

MylesBAstor

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Apr 20, 2010
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I hung on for a full 3 minutes. Common mode noise attenuation and not passing DC are characteristics for any galvanicly isolated transformer, whether a typical isolation transformer, or a balanced/technical power transformer. The sole additional benefit of balanced/technical power is the (theoretical and lesser, actual) additional leakage current to ground cancellation.

Additionally, common mode mains noise attenuation is simply implemented with minimally current limiting common mode chokes and binocular cores. Minimizing dc on a mains is also straightforwardly accomplished without risking saturation on a transformer. FWIW

-Paul

Yes but as I understand it Paul and correct me if I'm wrong, transverse rather than common mode noise rejection is far more important.
 

ddk

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May 18, 2013
6,261
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Hang on a minute! So is the proposition that removing common mode noise ( the greatest pollutant present in the electrical grid in my experience) and DC ( transformers cannot pass DC) from the mains power line = sonic coloration? If so we had better inform many of the worlds leading recording studios and broadcasters of their folly of using balanced power supplies with their equipment.

You're assuming what is present in the grid, along with its affects on a particular system and assuming that transformer X is only cleaning up "benignly" what you assume to be a problem without affecting anything else in the process.

You're also assuming that we all agree on the "leading studios", and assuming that we agree on that you have to assume the same equipment, conditions, goals and end up with the same results at the end of the day! The assumption is also that they went back and forth several times after the installation of such transformer and confirmed all its affects and then settled on it. Of course you're also assuming that after doing such tests they all decided to keep their transformers, right?

You last assumption is that what one does in the studio is always the right one, if that was true, we'd all be running balanced systems at home! Or just talk to some of these recording engineers about wires and power cords.

That's a lot of assumptions and you know what they say about assuming!

david
 

Occam

[Industry Expert]
Dec 15, 2010
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Yes but as I understand it Paul and correct me if I'm wrong, transverse rather than common mode noise rejection is far more important.

Hey Myles,

You might well be right. I was simply responding to TPI's assertions. Transverse/normal/differential mode noise is more problematic than common mode noise. In a mains transformer, differential mode coupling is primarily capacitive which with transformers is attenuated via an inter-winding grounded shield between primary and secondary and/or split bobbins. Torus transformers enhance their normal mode attenuation by using Menno Van derVeen's patent utilizing an additional winding and a capacitor.
Non transformer normal mode attenuation, beyond parallel capacitors across line and neutral, those with series inductance, inevitably elicit objections to their current limiting potential. This is certainly applicable to power amps, depending on many things. On source components, inductive elements are available with both substantial common mode inductance 27mh as well as a full 1 mH of leakage/differential inductance with a 3 amp rms capability. This allows, with care regarding the low pass' Q via choice of the X cap's value(s), rather strong filtering. That being said, IMO the proper place for power conditioning is within each component. From an economic perspective, that probably isn't going to happen.

Regards,
Paul
 

TP1

Well-Known Member
Apr 2, 2014
26
4
298
I hung on for a full 3 minutes. Common mode noise attenuation and not passing DC are characteristics for any galvanicly isolated transformer, whether a typical isolation transformer, or a balanced/technical power transformer. The sole additional benefit of balanced/technical power is the (theoretical and lesser, actual) leakage current to ground cancellation.

Additionally, common mode mains noise attenuation is simply implemented with minimally current limiting common mode chokes and binocular cores. Minimizing dc on a mains is also straightforwardly accomplished without risking saturation on a transformer. FWIW

-Paul

Great theory - But in the real world when every single item of equipment in the audio chain does not have adequate mains noise cancellation or DC rejection, you all always get an improvement with these devices. In any event, no item of equipment will remove as much mains noise as it would a combination of Balanced transformer and the equipment. I have even improved the output of a PS Audio P10 by plugging it in to a 5 KVA balanced transformer. ( I have both units).

I will add that most equipped that was supposed to be adequately choked did improve (when I experimented with them) with either a Balanced transformer or a P1O. Notable exceptions were Soulution and Halcro equipment ( latter advised by friend who did same experiments).
 
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TP1

Well-Known Member
Apr 2, 2014
26
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298
Hey Myles,

You might well be right. I was simply responding to TPI's assertions. Transverse/normal/differential mode noise is more problematic than common mode noise. In a mains transformer, differential mode coupling is primarily capacitive which with transformers is attenuated via an inter-winding grounded shield between primary and secondary and/or split bobbins. Torus transformers enhance their normal mode attenuation by using Menno Van derVeen's patent utilizing an additional winding and a capacitor.
Non transformer normal mode attenuation, beyond parallel capacitors across line and neutral, those with series inductance, inevitably elicit objections to their current limiting potential. This is certainly applicable to power amps, depending on many things. On source components, inductive elements are available with both substantial common mode inductance 27mh as well as a full 1 mH of leakage/differential inductance with a 3 amp rms capability. This allows, with care regarding the low pass' Q via choice of the X cap's value(s), rather strong filtering. That being said, IMO the proper place for power conditioning is within each component. From an economic perspective, that probably isn't going to happen.

Regards,
Paul

I am talking from experience and practical experiments only. Theories of what causes which effect are fine but we shouldn't dwell on them for for too long without undertaking experiments to test those theories.

For that purpose, a group of us in my neck of the woods ( Western Australia) compared different power regenerators, filters and balanced transformers. The two most effective on the day were PS Audio P10, and a 3KVA Airlink Balanced power supply - in that order. A subjective estimate would place the balanced transformer at around 85-90% of P10. The P10 also lowered the THD of the mains supply from around 2.6% to 0.1%. A power regenerator will act upon most facets of mains pollution including traverse, normal and common mode noise. The excellent performance of the balanced power supply gives substantial weight to the importance of common mode noise.

Think about it, the biggest contaminants of the power lines comes from industry , switch mode power supplies etc and of course that noise will be present on both lines. But please folks, don't be content with theory or even my findings on this, find someone with a decent balanced power transformer and cajole them into letting you try it. And be prepared to be pleasantly surprised.
 

Occam

[Industry Expert]
Dec 15, 2010
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TP1,

Sorry if I didn't make myself clear. I've no problem with balanced / technical isolation transformers. If they work in your and other's systems, that's great. I was simply being pedantic. You said that the benefits were -
Hang on a minute! So is the proposition that removing common mode noise ( the greatest pollutant present in the electrical grid in my experience) and DC ( transformers cannot pass DC) from the mains power line = sonic coloration? If so we had better inform many of the worlds leading recording studios and broadcasters of their folly of using balanced power supplies with their equipment.
I simply pointed out that you missed the sole benefit unique to balancing transformers, which is its ability to cancel leakage currents to the safety ground. The 2 benefits you mentioned, common mode noise attenuation and DC 'removal' are characteristics of any mains isolation transformer, whether MGE, Topaz, Torus, Equitech, or BPT... balanced or not.
I'm not questioning your subjective preferences, just making a pertinant technical correction.

Regards,
Paul
 

TP1

Well-Known Member
Apr 2, 2014
26
4
298
Everything has a 'signature/coloration' to various degrees, there's no getting away from that. The type of 'signature/coloration' and the amount of intrusiveness might be different but its always there.



I never made a quality judgement on your sound, just that I heard the transformer 'signature/coloration' in your room. I also have a transformer in my system and I hear the same 'signature/coloration' affect the harmonics when its plugged in.



Sure, every installation is different and your installation will have its own 'signature/coloration' as will mine, but that's separate from the 'signature/coloration' of the transformer, they do what they do.



Performance doesn't mean lack of 'signature/coloration', just difference. Also from what you're telling me you're not comparing apples with transformer to apples without the trans, you're comparing completely different species of fruit.

david

The power from the wall has the sonic signature or coloration of the power company's neighbourhood transformer, the power lines in between and all the pollutants that are present in the grid. It is by no means a neutral starting point. So any departure from that does not mean the transformer is adding coloration, it could be removing it in an absolute sense.
 

TP1

Well-Known Member
Apr 2, 2014
26
4
298
TP1,

Sorry if I didn't make myself clear. I've no problem with balanced / technical isolation transformers. If they work in your and other's systems, that's great. I was simply being pedantic. You said that the benefits were -

I simply pointed out that you missed the sole benefit unique to balancing transformers, which is its ability to cancel leakage currents to the safety ground. The 2 benefits you mentioned, common mode noise attenuation and DC 'removal' are characteristics of any mains isolation transformer, whether MGE, Topaz, Torus, Equitech, or BPT... balanced or not.
I'm not questioning your subjective preferences, just making a pertinant technical correction.

Regards,
Paul

Hi Paul

I did misinterpret what you said in regards to leakage currents but common mode noise rejection is not performed by isolation transformers, only by balanced isolation transformers.

Isolation transformer

isolation_diagram.png

Balanced isolation Transformer

out_of_phase_diagram.png

Quoting from the Airlink site:

"The balanced transformer has a symmetrical pair of out of phase voltages. The two ‘live’ wires are inversely phased, centre-tapped to earth. Any (common-mode) reactive currents are likewise inversely phased. At the central earth point these equal & opposite currents meet and cancel each other out, they are not superimposed on the earth."
 
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Occam

[Industry Expert]
Dec 15, 2010
117
1
0
NYC
Hi Paul

I did misinterpret what you said in regards to leakage currents but common mode noise rejection is not performed by isolation transformers, only by balanced isolation transformers.
.....

Quoting from the Airlink site:

"The balanced transformer has a symmetrical pair of out of phase voltages. The two ‘live’ wires are inversely phased, centre-tapped to earth. Any (common-mode) reactive currents are likewise inversely phased. At the central earth point these equal & opposite currents meet and cancel each other out, they are not superimposed on the earth."

The above paragraph from Airlink is saying the very same thing about balanced / technical power as I did, reactive leakage currents from fed components are nominally summed and canceled at the secondary center tap. It has NOTHING to do with attenuation of mains borne common mode noise, which is an inherent characteristic of isolation transformers. Airlink's paragraph is talking (IMO awkwardly) about 'Any (common-mode) reactive currents', what I referred to as leakage currents, not common mode noise.

I am talking from experience and practical experiments only. Theories of what causes which effect are fine but we shouldn't dwell on them for for too long without undertaking experiments to test those theories.

Ummmm.... One shouldn't try to teach their Grandmother how to suck eggs. ;)

-Paul
 

TP1

Well-Known Member
Apr 2, 2014
26
4
298
You're assuming what is present in the grid, along with its affects on a particular system and assuming that transformer X is only cleaning up "benignly" what you assume to be a problem without affecting anything else in the process.

You're also assuming that we all agree on the "leading studios", and assuming that we agree on that you have to assume the same equipment, conditions, goals and end up with the same results at the end of the day! The assumption is also that they went back and forth several times after the installation of such transformer and confirmed all its affects and then settled on it. Of course you're also assuming that after doing such tests they all decided to keep their transformers, right?

You last assumption is that what one does in the studio is always the right one, if that was true, we'd all be running balanced systems at home! Or just talk to some of these recording engineers about wires and power cords.

That's a lot of assumptions and you know what they say about assuming!

david

That seems like disinformation to me. I am trying to pass on experiences to fellow audiophiles, if you have something to sell or a vested interest , or simply a favoured approach, you should just say so that other people can benefit, Throwing theoretical negatives around serves no helpful purpose.
 

pcosta

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Jul 25, 2010
364
123
950
Windsor, Ontario, Canada
Hi Paul

I did misinterpret what you said in regards to leakage currents but common mode noise rejection is not performed by isolation transformers, only by balanced isolation transformers.

Isolation transformer

View attachment 15867

Balanced isolation Transformer

View attachment 15868

Quoting from the Airlink site:

"The balanced transformer has a symmetrical pair of out of phase voltages. The two ‘live’ wires are inversely phased, centre-tapped to earth. Any (common-mode) reactive currents are likewise inversely phased. At the central earth point these equal & opposite currents meet and cancel each other out, they are not superimposed on the earth."

Now would the isolation transformer in my original question be used as a "balanced" unit if anyone knows the MGE transformers.
 

TP1

Well-Known Member
Apr 2, 2014
26
4
298
The above paragraph from Airlink is saying the very same thing about balanced / technical power as I did, reactive leakage currents from fed components are nominally summed and canceled at the secondary center tap. It has NOTHING to do with attenuation of mains borne common mode noise, which is an inherent characteristic of isolation transformers. Airlink's paragraph is talking (IMO awkwardly) about 'Any (common-mode) reactive currents', what I referred to as leakage currents, not common mode noise.



Ummmm.... One shouldn't try to teach their Grandmother how to suck eggs. ;)

-Paul


You described your earlier post as pedantic and i agree with it. All the transformer manufacturers describe the balanced transformer attributes, as cancelling common mode noise through combining 2 out of phase voltages. Describe it as you like.


As far as teaching Grandma to suck eggs , it is sometimes necessary when she becomes forgetful.:D
 

ddk

Well-Known Member
May 18, 2013
6,261
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Utah
That seems like disinformation to me. I am trying to pass on experiences to fellow audiophiles, if you have something to sell or a vested interest , or simply a favoured approach, you should just say so that other people can benefit, Throwing theoretical negatives around serves no helpful purpose.

You caught me, I own The POWER Company $$$$:cool:$$$$. And thank you, this was very informative.

Hang on a minute! So is the proposition that removing common mode noise ( the greatest pollutant present in the electrical grid in my experience) and DC ( transformers cannot pass DC) from the mains power line = sonic coloration? If so we had better inform many of the worlds leading recording studios and broadcasters of their folly of using balanced power supplies with their equipment.
 

microstrip

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May 30, 2010
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(...) All the transformer manufacturers describe the balanced transformer attributes, as cancelling common mode noise through combining 2 out of phase voltages. Describe it as you like.

Yes, but we should remember that most of the noise in power supplies is NOT common mode noise and the common mode rejection is very poor at high frequencies.
 

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