Does an isolation transformer improve a power cable?


In a post dated 12/14, I described how I built my DIY AC power cables. In evaluating these new cables over the first 100 hours, I am hearing parts in music I did not know where there--instruments are standing out in sharp relief with a more robust dynamic and improved clarity. All of this is coming through via Furutech's Ohno Continuous Cast copper, a brand I am not here to promote--rather, it is the one I chose to obtain a legitimate OCC material. These cables are feeding two ARC Reference 210's, modifed to 250's. But, what appears to make as important a contribution is what is feeding the AC cables their current--a large 240V/120V isolation transformer weighing 120 pounds and supplying 4000 watts of work to all of my devices via six outlets on the back. What I am understanding is that this thing provides a more ideal supply of current that is independent of the rest of the house and its appliances and devices. With all that is said about power cables and what they can and cannot do, depending on one's beliefs about alternating current, i.e., what is upstream, how could it matter, what about the rest of the grid, the last six feet is important, etc, I suspect that, in using a true induction transformer in this manner, the last six feet is the only six feet in my power supply, and this is why these OCC cables sound so stunningly good. Is this the purest AC energy pathway possible?
Convert?fit=crop&h=128&rotate=exif&w=128jafreeman
IMO: The Isolation transformers should clean the AC line going to your audio outlets giving you a blacker background hence you hear more details in the music. The actual power cord can also inhance the sound.
This is what I've been doing for power filtration in my system for the past 18 years or so. I'm not sure if answered your question or if I'm capable of answering it in technical terms.
Lak--yes, the isolation transformer does provide a clean, stable current. My amps read 121 volts input with these large AWG cords, but what I am doing here is plugging my transformer into a 240V wall outlet I installed using 10-2 Romex. The transformer sits under my equipment--it is right there, next to my amps. From the transformer's outlets, I am running these new OCC AC cables directly into my amps' IEC receptacles. What I am seeing here is that there is no grid upstream--just six feet of ultra pure copper as the "last" and only six feet of AC cable--a private power grid. Correct me if I am wrong, but this appears to be a breakthrough realization in providing ultra smooth, quiet power, even though there is a core in the transformer that appears in diagrams to be a material link between the two windings. Even so, this arrangement is giving me something that asks for further consideration. I would like some more input from those with some expertise, Lak included.
Isolation transformers are used to isolate electronics/ devices from the primary source of power. The benefit of this is that the ground is now independent of everything else so ground loops can go away and short high spikes in electricity do not affect the other side.

In your use, you may be getting some positives from the ground loop issue. Also if you have "dirty" electricity with a high frequency noise in it that is probably being filtered out. A transformer is basically two inductors with a iron loop connecting them to pass the field. At high frequencies inductors act as resistors.

So based on the cable you are using I think you believe in the need for quick clean power to your amp to deal with the high frequency shifts caused by power changes on the power supply in your amp. An isolation transformer will most likely do the opposite, it will not allow the amps power supply to fluctuate quickly.

If you want really clean power that is isolated you would need a bunch of batteries and a really good inverter, much like you see in many high end solar projects.
where do you get a isolation transformer from?, what is one of the better brand's?, do they make bigger than 4,000 watt's for home audio?
Hi Audiolabyrinth

The isolation transformers I use in my system are industrial ones like Topaz. They range from 1 kVA to 2.4 kVA. Another one I use are older Tice Power blocks. The con of these isolation transformers are they are big bulky and not the prettiest to look at.

I've got them from various outlets. Audiogon, Ebay, and Craigslist.

The isolation transformers I use in my system are industrial ones like Topaz. They range from 1 kVA to 2.4 kVA. Another one I use are older Tice Power blocks. The con of these isolation transformers are they are big bulky and not the prettiest to look at.
12-29-14: Jedinite24

Jedinite24,

Are the outputs of the transformers grounded AC power systems, therein single ended 120V with a Hot ungrounded conductor and a neutral grounded conductor? If they are wired in this fashion have you ever checked to make sure the outputs are all in phase with one another?

Simple test is to measure for voltage from the Hot ungrounded lead from each output of each ISO transformer to the Hot ungrounded lead of the other ISO transformers. (Hot contacts of connected receptacles of each ISO transformer output to the hot receptacle contact of the other ISO transformers). If the outputs are in phase you will measure zero volts nominal. If any are out of phase with one another you will measure 240V nominal. For audio equipment connected together by ICs it is best to have the outputs of the ISO transformers in phase with one another.

Same goes for an ISO transformer/s that are used to power some equipment and the 120V wall mains receptacle, fed from the existing house electrical panel, is used to power other equipment where the audio system is connected together by ICs. The grounded AC output of the ISO transformer/s should be in phase with the wall mains receptacle.

Jim
I have taken the easier but more expensive route by using plug-and-play transformers that are made to sit with your gear, not in the basement under your breaker box. The two best known audiophile brands are Richard Gray and Torus/Bryston. These products have their own AC power cables that simply plug into a wall outlet. I happen to use the Richard Gray Rack Mount Pro. The model below that is their Substation. Their largest is the Powerhouse. The Torus products come in various power outputs, as well. In any case, I would only use a 240V/120V version. All you need is a 240V outlet next to your gear--simple, clean, direct with no worries about phase. The 240V versions deliver more wattage, and this is what you want--a dedicated 120V, 20 amp line will deliver 2400 watts, so you want to equal or exceed that. If you are running two 20 amps lines for two big mono blocks and subwoofers, then you may need an isolation transformer for each side of your system. I also use the RGPC 1200C for my front end. These are all expensive, though, and heavy, as they should be. They do not limit peak demands, they supply them, and, as said, they isolate your system away from ground and grid. Results in my old house have been a broader, more relaxed and articulate low end and sound stage. The new AC OCC cables have taken everything to a new plateau of clarity and presence.
All you need is a 240V outlet next to your gear--simple, clean, direct with no worries about phase.
12-29-14: Jafreeman
Jafreeman,

I agree I would feed a 4KVA ISO transformer with 240V as well. Better for isolation of the ISO transformer as well as for balancing the mains of the electrical service panel.

As for phasing if you are by chance referring to my above post it doesn't matter if the primary is fed by 240V or 120V. The outputs of ISO transformers could still end up out of phase with one another.

Jim
Thankyou for your reply's jedinite24 and jafreeman, the plug and play sounds like a good idea.
Jea48, Hi Jim, I need to E-mail you concering my power, will this be ok?, it is not about this topic here.

Audiolabyrinth,

Sure, no problem.

Jim

Thankyou for your reply's jedinite24 and jafreeman, the plug and play sounds like a good idea.
12-30-14: Audiolabyrinth
Audiolabyrinth,

If you decide to try an isolation transformer you should first do a little research on the different types of isolation transformers and the proper grounding methods used for the output of the transformer.

An isolation transformer creates a new separately derived AC power system that is independent from the mains power of your home's AC power system. Example, if the primary winding of an isolation transformer is fed from the mains of your home, be it 120V or 240V, the output of the secondary winding will not have any reference relationship to the mains power of your home. The output of the transformer will be floating above ground so if you were to measure for voltage from either hot lead of a 120V out secondary winding to the earthed ground of you home you would measure zero volts. (I should note with a digital meter you may get a phantom reading, it is not a true power voltage reading.) So what you have is a separately derived 120V AC Isolated Power System, with 2 Hot ungrounded Lines, legs floating above ground.

NEC Code prohibits this type of power system to be used by non-qualified personnel. It should never be used for home audio equipment. Where this type of power system is used is in hospital OR rooms, ER rooms, and CATH Lab rooms, where electrical monitoring equipment is connect to a patient. NEC Code requires special Line Monitors to detect any power leakage to the ground plane of the room. For instance if a leakage of more than 4 milliamps is detected from any hot ungrounded conductor to ground an alarm will sound in the room and notify the medical staff there is a problem. The medical staff can then look at a milliamp meter and see how much leakage is present.The Line Monitor does not turn off the power.

It is also used in foundries where a ground fault condition could cause a loss of power. Again it is monitored by qualified personnel as well as Line Monitors connected to the mains.

Another place an isolation power transformer, configured as an Isolated Power System is used is on the test bench of an Electronic Tech. I have seen them used on the benches of hospital Bio Med and Bio Tech labs. Again for qualified professional use only. With this type of 120V Isolated Power System the unit just plugs into the 120V wall outlet and outputs 120V floating above ground AC power.

Plug and play? Be careful these are sold to the unbeknown general public through the likes of EBay and elsewhere. They are usually listed as Medical Isolation transformers.

Plug and play isolation transformers for the general public's use need to have a grounded AC output. This type of power system is called an AC Grounded Power System.

In the case of a straight 120V output one lead, leg, of the secondary winding is intentionally grounded and becomes the neutral conductor. One method used is to connect the lead, leg, to the metal case of the transformer. This common point will become the Star grounding point for the neutral conductor/s and the equipment grounding conductor/s for the connected receptacle/s. From this Star grounding point the equipment grounding conductor of the power cord that feeds the primary winding of the transformer is connected. This becomes the earth ground. From the same Star ground connection, a white color insulated wire will connect to the neutral contact on the 120V receptacle. Next from the same Star ground connection a green color wire will connect to the green equipment ground screw on the receptacle.
The remaining Hot ungrounded conductor of the secondary winding of the transformer will connect to the hot contact of the receptacle. (Note for larger VA rated transformers where the available power could exceed the rating of the receptacle, overcurrent protection would need to be added between the hot lead of the transformer secondary and the receptacle.)

If by chance you buy a plug and play isolation transformer with straight 120V out check the output with a three wire plug in polarity/ground checker to make sure the output of the unit is a grounded AC power system.
You can also use a volt meter to check. If the unit is wired as a Grounded AC Power System insert one test probe in the hot contact of the receptacle and the other test probe in the equipment ground U shaped hole of the receptacle, or the metal case of the unit. If the output is wired as a Grounded AC power System you will measure 120V.
From the neutral contact of the receptacle to the ground you will measure zero volts.

If you end up with a plug and play AC Isolated Power System isolation transformer you can easily rewire the output making it an AC Grounded Power System.

Note, an isolation transformer with its output wired as an AC Grounded Power System will yield the same isolation results as that of an AC Isolated Power System.

Also note, I did not mention the so called Balanced Power System commonly referred to as 60V - 0V - 60V. That would be another post altogether.
I believe that is what Jafreeman has .
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Jim

I use the Equi=tech 10WQ wall panel system which includes a 10kva isolation transformer. when I installed this 400 pound panel 4 years ago I did have to re-think the power cords in my system. previously I had Jena Labs Fundamental One power cords with in-line power conditioners. however; once I cleaned up the noise in my power grid with the Equi=tech isolation transformer the Jena Labs actually added noise. so I switched to a more simple approach in a power cord, the Absolute Fidelity power cords for most of my gear. I have 9 of those. they are very simple and quiet. I do use 2 Evolution Acoustics TRPC (triple run power cords) on my 2 dart mono block amplifiers.

some power cords do filter noise, and some do not.

so no, an isolation transformer does not improve a power cord, but it does change the context it is used in. so you must investigate the performance equation for the specific power cord in the new context. I suppose it is possible that the isolation transformer might improve the total picture. but unless you try some alternatives you won't know if the power cord you have always used is holding you back.

you gotta listen.
I totally agree with the comment Mikelavigne made regarding power filtration and the use of power cords. I have noticed that in my systems also. A very well made point.
Jafremman,

Richard Gray Power Company makes the "Sub station" isolation transformer in both 102/240V options. It has been in production for more than 10 years. Yes, these devices serve as a resivor for clean power reserve. Additionally, these devices clean your power coming into your dwelling from your power company's line-transformer. Very cool stuff indeed. Lastly, consider a dedicated line for your gear if you live on the "grid". Keep me posted & happy listening! JA
Mike, the Equ=tech 10wq system looks like a superb product--I am sure it is giving you a very quiet power supply that allows all the inner details to come through. Jea, the unit I am using must be a grounded power system, as it has six grounded receptacles on the back. Looking at these transformers form RGPC and Torus/Bryston, they are very domesticated, made for the living room. There isn't anything easier--just plug it into the wall and plug your gear into it. What I am getting at is that, if this is a truly isolating transformer, then there is nothing upstream of it--forget about the house and all the big appliances, all the switching noise, the voltage sags, the buzzing dimmer switches, waiting until midnight for the best sound, etc. All the power is right there with your gear. Beyond that, there are only your own power cords--your own AC lines. Now, use the best copper available, and you have this nailed. I cannot think of a more pure atomic structure than OCC copper. You are down to an element here. It is free of other metal impurities and oxygen. It has no grain boundaries that cause distortions; the electromotive force alternates back and forth along shared electrons quietly. Your gear operates in an ideal power environment. The music signal is modulated onto this pure power source, so this is what you want from your power. I don't have any EE knowledge beyond what I can read and understand, but sometimes this allows a basic idea to come through as perhaps a profound revelation. I am trying to tell you that two AC power cords are acting like a front-end upgrade here--if I only had words.......In the spirit of reporting great things in this community, I just want to tell all of you, and if just one person also tries this combination, then something has been accomplished. Best wishes for health and a Happy New Year to all.
I am getting at is that, if this is a truly isolating transformer, then there is nothing upstream of it--forget about the house and all the big appliances.

No.... If you have a drag on your power system, like a big appliance you will have the same drag on the other side of the transformer. The electricity is not made at the transformer it just isolates it from the other side.
If you want to eliminate the reactive noise coming back up the ground you can lift the ground. I don't recommend doing it long though.

As stated above by another poster, these sorts of things are really used in hospitals, industrial use and labs that need to protect incredibly sensitive electronics.
Remember, in your amp there is already a transformer so theoretically your rails are already separated from the electrical mains. And those transformers are typically balanced out so you are getting those same effects of cancellation already.
Jafreeman,

Just a guess the old power cords you were using on your amps was affecting the sound quality of your amps. It could be they might be shielded in some way, or maybe the design construction of the cable was adding capacitance or inductance to the power being delivered to the power transformers of the amps. It is amazing how a power cord can affect the sound quality of a piece of audio equipment. It is obvious from your comments the amps prefer the new power cords better.

I do have a question about the Richard Gray RM PRO isolation
power unit, is it "Balanced Power" out there in 60V - 0V - 60V when referenced to ground, or is it so called single ended out 120V to ground? I cannot find a picture of the back of the unit anywhere.

Designed to provide 4.0KVA 240V/120V Isolated Pure AC Power utilizing AV grade magnetics for optimum
performance, allows you to deliver true balanced power all the way to the equipment rack before it is
stepped down to 120V. This results in added protection against lightning, EMI/RFI and Harmonics and a
more efficient way of Powering and Protecting your equipment.
The SubStation RM Pro has 6 (5-20R) protected outlets and a 7 ft 12 AWG power cord terminated to a
NEMA 6-20P plug.
http://www.richardgrayspowercompany.com/isolation_manual.pdf

Edit.
Reading the PDF info again I think it is saying the primary winding of the isolation transformer is being fed by 240V balanced power. Just a guess, I think, the secondary is configured straight single ended 120V out.
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Jim
reading thru this thread there are lots of numbers being tossed around about output of isolation transformers, gauge of wire, and such things.

what appears to be unclear is what sort of amperage is being supplied to these devices from the power grid of the household. an isolation transformer plugged into a 20amp circuit cannot output 4000 watts.....no matter what it's output capability might be. the limitation will always be the amount of amperage input.

stand alone boxes not hard wired into the power grid have limitations as to output. and they typically cannot fully supply the needs of high powered amplifiers.....although there are exceptions. mostly they will limit dynamics of very high powered amplifiers. it's about how much headroom the power grid has to handle musical peaks at those moments when the amplifier demands lots of power right now. line sag comes thru as compression and hardness in the music.

stand alone isolation transformers plugged into a wall outlet can predictably effectively power source gear as they don't have the same huge momentary demands on the amperage.

it can become a choice between lower noise and more dynamic energy when deciding to use a stand alone isolation transformer....or not on power amplifiers.

an isolation transformer plugged into a 20amp circuit cannot output 4000 watts.....no matter what it's output capability might be. the limitation will always be the amount of amperage input.
12-31-14: Mikelavigne

Hi Mike,

Jafreeman's Richard Gray 4KVA isolation transformer unit is fed by 240V, 20 amp circuit.

240V X 20 amps = 4800VA

4000VA / 240V = 16.67 amps.

Jafreeman installed # 10 AWG wire. Wire is rated for 30 amps.
I would have installed # 10 wire as well.
16.67 amps X 125% = 20.8 amps

Gray/Manufacture specs the unit be fed by 240V, 20 amp circuit.
Receptacle needed, NEMA 6-20R 250V 20 amp. Breaker at main electrical panel a 2 pole 20 amp.

FLA continuous available amps at 120V output.
4000VA / 120V = 33.3 amps.
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Jim

Jafant, yes, I have had the 240V/120V Substation and the upgraded to the RM Pro for even more power and outlets. Yes, I have a dedicated 240 volt line, made from 10 AWG Romex and a 30 amp breaker.
Svan, even though power is not made at the transformer, it makes a lot of power available. Mine receives 240V via 30 amp service = 7200 watts. It steps the voltage down to 120V and preserves 4000 watts available for devices, and, as claimed by the manufacturer, it is all isolated from the house. My amps tell me this--they read at 121 volts constant. The Substation before it that outputted 2400 watts gave them 118 volts constant. No need to lift the ground--the house ground is not involved, again, as claimed--no ground loop issues at all. And this is what I am experiencing during listening. The amps are perfectly quiet and there is no effect on the sound from my house, including an electric range, the furnace, AC, 1/2 horse garage door opener, etc. If you read the claims made by the makers of these transformers, and if you believe them, then all that is left is to try them. I have them, and they have given me stellar results, and I live in a first-ring suburb with above-ground wires on poles that are > 40 years old. The neighbors' appliances don't bother me, either. But what I originally posted was a question about my new AC power cables, and I am answering yes to my own question, and I stand by this.
Yes, I have a dedicated 240 volt line, made from 10 AWG Romex and a 30 amp breaker.
01-01-15: Jafreeman
The 30 amp breaker does nothing more for the available power the ISO xfmr can draw from the main electrical panel than the correct size 20 amp breaker would. The total power that the ISO xfmr can deliver to the connected load is limited by the circuit breaker mounted in the front of the ISO xfmr unit. That breaker is there to protect the unit from a continuous overload or short circuit.
The current carrying contacts inside a 30 amp breaker are exactly the same size as a 20 amp breaker. The only difference is the thermal and magnetic trip unit settings.
The #10 wire was a good idea but it should be connected to a 2 pole 20 amp breaker.

There is a reason why the manufacture of the ISO xfmr specs a 20 amp circuit, there in a 20 amp breaker. He is following NEC Code which says a 20 amp rated receptacle can only be connected to a 20 amp breaker.


No need to lift the ground--the house ground is not involved,
I hope that does not mean a separate earth ground, ground rod, that is not connected to the main grounding system of the electrical service of your home.

There is a reason why NEC Code requires the neutral conductor of a separately derived power system, (there in the neutral conductor of the secondary winding of an ISO xfmr), to be connected to the main grounding electrode system of the main electrical service. It can be connected to it at any point. (Technically a safety equipment grounding conductor is not part of the grounding electrode system, though it connects to it.)

If you do have a dedicated earth ground that is totally separate from the main grounding system of your home I hope you did not break the equipment grounding conductor/connection that connects to the ISO xfmr unit from the 240V branch circuit that feeds the unit. That could be dangerous.

The Earth does not possess some magical mystical power that sucks nasties from an audio system.
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mmmm, this thread is informative, jea48, please call me, if you recieved my #, I have done what you have specified, LOL!, everything in my house affects the sound of my sysytem, I have dedicated lines, I need dedicated breaker box with it's own ground for the system!, the ground is where this problem is, there is no other answer?
Jim, thanks for that clarification. I should have said that the ampacity I ran ends at my receptacle. Beyond that, the product supplies a 12 AWG cord and a 20 amp breaker. The cord is grounded to my receptacle and into the transformer. The company claims of protections from surges, elimination of ground loops--at least between gear in the system-- instantaneous power on demand have led me to believe this is an isolated power supply. At any rate, the results say just that--there is no noise, there is no loss of voltage, no clipping, a vastly improved soundscape--lots of "headroom". I have not altered the unit in any way--it is plug-and-play--just need the outlet. They are expensive-got mine for half cost here on 'Gon from an installer who had an extra--otherwise, would have tried Torus Power, also very costly, but well regarded.
I just wanted to report my findings using OCC copper in my DIY AC cables that are supplied by this clean power---outstanding!
I wonder if anyone has converted 3 phase to a home use 120 line like this. I suppose that would even give better quality AC.

Just to be a bit of naysayer/ clarifier the transformer does not "create" electricity as I have stated before. It is just isolating you from the grid from "quick" spikes and drops, any long term spike or drop will effect the other side of the transformer.

The best way for clean AC is to have your own method of developing the AC signal from either using the grid power to DC and then back to AC or from off the grid sources as in solar and wind. The last two are becoming quite popular and should be able to create amazingly clean power (based on the inverter)
Just to be a bit of naysayer/ clarifier the transformer does not "create" electricity as I have stated before.
01-02-15: Scvan

Scvan,

Other than you, who has made such a statement?

~~~

Separately Derived System.

NEC 2011
Article 100
Definitions

Separately Derived System.

A premises wiring system whose power is derived from a source of electric energy or equipment other than a service. Such systems have no direct connection from circuit conductors of one system to circuit conductors of another system, other than connections through the earth, metal enclosures, metallic raceways, or equipment grounding conductors.

>>>>>>>>>>>>>>>


The revised definition in the 2011 NEC defines Separately Derived System as: A premises wiring system whose power is derived from a source of electric energy or equipment other than a service. Such systems have no direct connection from circuit conductors of one system to circuit conductors of another system, other than connections through the earth, metal enclosures, metallic raceways, or equipment grounding conductors.
http://www.jade1.com/jadecc/courses/UNIVERSAL/NEC05.php?imDif=10

http://www.jade1.com/jadecc/courses/UNIVERSAL/NEC05.php?imDif=10

>>>>>>>>>>>>>>


A separately derived system is a premises wiring system with no direct electrical connection to conductors originating from another system [Art. 100 definition and 250.20(D)]. All transformers, except autotransformers, are separately derived because the primary circuit conductors do not have any direct electrical connection to the secondary circuit conductors. Generators that supply a transfer switch that opens the grounded neutral conductor would be considered separately derived [250.20(D) FPN 1].
http://ecmweb.com/nec/grounding-and-bonding-separately-derived-ac-systems

An Isolation transformers is a Separately Derived System.

>>>>>>>>>>>>>>>>


Separately Derived System. A premises wiring system whose power is derived from a source of electric energy or equipment other than a service. Such systems have no direct electrical connection, including a solidly connected grounded circuit conductor, to supply conductors originating in another system.

.
.

Some examples of separately derived systems would include:
•Transformers, shown in photo 1, where the supply side is isolated from the derived side except by magnetic coupling
•Generators (motor, wind, or engine driven), one example shown in photo 2 and figure 1, where it is either a totally stand-alone system or is an alternate source of power and the grounded conductor (neutral) is not solidly connected in the transfer switch or transfer equipment
•Battery/inverter systems where the output is not interconnected
•Photovoltaic systems where there is no interconnection to the grid or another energy source (off grid system)

Some examples of separately derived systems would include:
•Transformers, shown in photo 1, where the supply side is isolated from the derived side except by magnetic coupling
http://iaeimagazine.org/magazine/2009/11/16/separately-derived-systems/

http://iaeimagazine.org/magazine/2009/11/16/separately-derived-systems/

*********************


The main benefit offered by Isolation Transformers is
the input-to-output isolation, where the output circuit
can be re-grounded and isolated from input or other
ground noise sources. This isolation can also be useful
where Ground Potential Rise protection can not be
afforded by normal bonding procedures.
http://www.erico.com/public/library/fep/technotes/tncr016.pdf
.
Jea48,

You are smarter than that. You know the definition of created.

If the voltage on the supply side drops it drops on the other side of a transformer. It isolated electricity it doesn't create it.

One side of the transformer has an electromagnet on it that created a field that oscillates at 60 hz. That field is transfered by the core to another set of wires that the field is inducted to. If electricity was truly being created, it would violate the first law of thermodynamics.

Definition of a transformer:
A transformer is an electrical device that transfers energy between two or more circuits through electromagnetic induction.
Transfer, not creation...

Isolation transformers block transmission of the DC component in signals from one circuit to the other, but allow AC components in signals to pass
hmmm... so if I have an AC noise or change in AC voltage will the isolation transformer let it pass or will it always be a perfect sinewave?

And for those that are excited about the idea of a balanced isolation transformer, from the NEC:
647.3 General. Use of a separately derived 120-volt single-phase 3-wire system with 60 volts on each of two ungrounded conductors to a grounded neutral conductor shall be permitted for the purpose of reducing objectionable noise in sensitive electronic equipment locations provided that the following conditions apply.

(1) The system is installed only in commercial or industrial occupancies.
Again,

Just to be a bit of naysayer/ clarifier the transformer does not "create" electricity as I have stated before.
01-02-15: Scvan

Scvan,

You are the only one here that is saying a transformer creates electricity.

The rest of your post is just babbling.
.
Jea,

Weird because this is what you stated?
An isolation transformer creates a new separately derived AC power system that is independent from the mains power of your home's AC power system.

Maybe I misread it....
Jea,

Weird because this is what you stated?

An isolation transformer creates a new separately derived AC power system that is independent from the mains power of your home's AC power system.
12-30-14: Jea48

Maybe I misread it....
01-04-15: Scvan


Again,

Just to be a bit of naysayer/ clarifier the transformer does not "create" electricity as I have stated before.
01-02-15: Scvan


Exactly where in the sentence do I say an isolation transformer "creates" electricity? It does not….
Post in question.

Are you saying an isolation transformer does not "create" a "separately derived system" as defined by the NEC Code Definition? Is your hang up the word “create”? When an isolation transformer is connected to a grounded power system because the secondary is not electrically connected to the primary, the secondary output will be floating above ground. The secondary is isolated from the power source that feeds the primary in so far as there is not a reference, difference of potential, voltage, from its' output to the power source that feeds its' primary until one lead, leg, of the secondary winding is intentionally connected, bonded, to ground. (Ground being the main grounding system of the premises' electrical service.) This leg becomes the “The Grounded Conductor”, the neutral. A new grounded power system is created.

Here is a snippet from a book written by Henry Ott.
“3.1.6 Separately Derived Systems.” Do you find fault with what Ott said?
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Jafreeman,

Thanks for the clarification on the grounding of the Richard Gray RM PRO Unit.

The RM PRO is more than just an isolation transformer.
Richard Gray RM PRO
.
.
Here is a white paper from EXACTPOWER. (PDF). You may find it interesting reading.
.
Jim, thanks for that in-depth manual from Exact Power. This should be enough info for anyone who wants to improve power to a system. I'm still not sure where this leaves us on the question of a separately derived power source or an isolated ground. I know the primary winding is grounded to my house via the supplied cord--not sure what the secondary winding can claim when there is an iron core to aid in the induction of the stepped down voltage made available at the six outlets on the back. I can only say that, having gone up the chain from several 400s, to the Substation to the RM PRO, improvements have been dramatic. The 400s are meant for front-end pieces only, not amps. The 1200 is the best item for an entire front end. There is a guy who occasionally runs an ad for a new 1200, sells them for around $950, sez he can't give the warranty, but guarantees it will work. He's the real deal--I have two from him--guy named William Loni.

I'm still not sure where this leaves us on the question of a separately derived power source or an isolated ground.
01-07-15: Jafreeman
The secondary of the isolation transformer of the Richard Gray RM PRO unit is a separately derived system. The RM PRO unit also provides surge protection on the line side of the primary winding.

Here is just a snippet from a book written by Henry Ott.
Quote.
"Basically, in the case of a separately derived system, we start all over again, as if it was the main service entrance panel and we create a new single point neutral to ground bond."
End of quote.

3.1.6 Separately Derived Systems, by Henry Ott.

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What a shielded isolation transformer does.

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EXACTPOWER, PDF

Page 10
Quote.
"| "Residential Power Distribution & Grounding -
The Truth
In residential installations, a dedicated electrostatically shielded isolation transformer will act as a buffer
between the utility company electrical system and the protected electronics systems such as AV equipment,
home theater electronics, automation systems, and data devices. These isolation transformers must be
hard-wired by a licensed electrician.
This transformer, when correctly installed, is an effective “sink” for the collective ground leakage current of
multiple switch-mode power supplies found in almost all modern equipment. The AV and control system will
benefit from the improved power quality, greatly reducing the effects of ground loops through having a single
point source for power and grounding.
An isolation transformer is a device that prevents power quality problems by galvanically isolating the load
from the power source, and incorporates a new neutral conductor that is bonded to a newly derived system
ground. This newly derived neutral to ground bond eliminates common-mode voltages at that point, which
are usually the main cause of unreliable system operation, equipment failure and service calls."
End of quote.

I suggest you start reading from page 8.

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The 1200 is the best item for an entire front end.

What are you plugging the 1200 into? The RM PRO unit?

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As for an isolated ground not sure what you are referring to. If you mean an isolated ground for bonding the new neutral of the secondary of an isolation transformer that is a No No. The neutral must bond, connect, to the main electrical service grounding system of your home. The neutral bond, connection, in your case is made through the safety equipment grounding conductor of your 10-2 with ground branch circuit wiring that feeds the isolation transformer. Another good reason you used #10 wire for the branch circuit.
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Thanks for posting page 10. It seems to lean toward "...a newly derived system ground." At any rate, I am very pleased with this product, and yes, the 1200C is plugged into the RM PRO. This is what Richard Gray calls their IsoGray configuration, which provides even more isolation to the front end. I have only my Wadia 861 CDP/pre-amp plugged into my 1200C. The Wadia is babied with an ideal power source in this way. The 1200C could easily support separate CDP/transport/turntable/pre-amp. I have another one in another room for my plasma TV and Blu-ray player and a pre-amp, and I plug that one directly into the wall, which also works for the 1200C. A small stereo amp is plugged into the wall. But yes, the best set up is the IsoGray. A lot of people don't like RGPC, citing bad results, e.g., stifled dynamics, but others have found them to be very good. Whether Torus Power or RGPC or another, best to have the 240V/120V models so you have a lot of clean power right up next to your gear. Then, it is only a short run with a great AC cord, and this is, in my recent experience, a breakthrough finding.
Best Regards, Joe