Discussion of AC mains isolation transformers

[Superdad]

How the hell do you know this stuff?

 

I have a friend--his name is Google.

 

 

Wow, thanks Alex! Great to know they are from Cambridge and slightly embarrassed i did not know that as I live very close to there! Also makes me feel better about purchasing their product. Now i just need to sort out what size to look for and how much i actually want or need to plug into which i'll follow up with in another post.

 

Thanks again for the quick response...btw, love your LPS-1 it's fantastic.

Mark

 

Thanks for your kind words Mark!

 

But don't be embarrassed at all about ECA--Rockwell's Allen-Bradley bought them out in 1986 for $100 million, and I am sure that whatever division was handling the isolation transformers did not survive.

[marksas3]

I apologize if this has been asked or discussed yet but here's my question / scenario / setup....

 

I know much was talked about the importance of having everything on the same power strip connected to the transformer BUT, what if the 'other' components are of 'lesser importance' like TV, BRP, ATV etc...can these be kept separate from the important components?

 

In other words, like many people my setup is multipurpose. My multichannel equipment(5.1 setup) and 2 channel are all together and share the same Left/Right channel speakers, the AVR powers the center and surrounds. I keep them separate by using an integrated amp with a home theater bypass feature, so i use the AVR (Yamaha RX-A850) for TV, Blu Ray and ATV and use my Peachtree Nova integrated, Arcam DAC and microRendu w/ LPS-1 solely for 2 channel listening.

 

I base all my importance and upgrades at the moment on the 2 channel setup and want the music to be the best i can get it.

Behind my console that has my gear, i have 2 wall outlets, 1 outlet is on a dedicated 20A circuit and another is a common/shared outlet for the room. So...can i achieve the same great results with the iso transformer/power strip method with JUST the 2 channel gear plugged into it, i.e. Integrated amp, DAC, and LPS-1 for microRendu, and plug all of the other gear into the common/shared outlet?

 

In another room on the 2nd floor of the house is where my computer, modem and router are. I connect the microRendu with 15 meters of BJC CAT6A cable but there is also a network isolator in line, Emo systems EN-70HD, closest to the mRendu. The Router and modem are going to be plugged into a BK Precision 1604A isolator.

 

Here is how I was thinking i could hook this up...

 

2 Channel:

APC LE1200 > ISO Transformer/Simple power strip > Integrated amp, Arcam irDAC, mRendu/LPS-1, Sonos Connect

 

Multichannel:

2nd Wall Outlet > Power conditioner or Strip > Yamaha RX-A850, Subwoofer, Sony BRP, Apple TV3, LG OLED TV, Comcast Cable Box, 5 port Netgear Switch

 

I know that for now at least, the AVR and Integrated are connected with a pair of RCA's, however the AVR is OFF when i'm listening to the 2 channel setup. It's possible in the near future i might be replacing the Peachtree with another amp that may not have the HT Bypass feature, so the way i MIGHT install it is using a switch like the Niles SAS-1 which has a few ways of detecting a signal and i would run a pair of speaker wires from the AVR to the switch for the L/R ch only, and the same for the new integrated amp. The SAS-1 is auto sensing, it's adjustable and it works really well actually.

 

As i type this it kind of sounds like a big mess having all this gear together and trying to keep it 'separate', but i really don't have a choice. I refuse to use the AVR for music, it just doesn't suit me. If it ends up being a better choice to plug it ALL into a single iso transformer on the SAME strip than i would have at least 11 if not 12 pieces of gear.

 

Lastly, i didn't mention but is listed above, is the APC LE1200 voltage regulator, i bought a couple of these since they're so cheap and was thinking of putting one if both my main system and computer room.

 

THANK YOU for any help or suggestions in any facet of the above.

 

Mark

[JohnSwenson]

I apologize if this has been asked or discussed yet but here's my question / scenario / setup....

 

I know much was talked about the importance of having everything on the same power strip connected to the transformer BUT, what if the 'other' components are of 'lesser importance' like TV, BRP, ATV etc...can these be kept separate from the important components?

 

In other words, like many people my setup is multipurpose. My multichannel equipment(5.1 setup) and 2 channel are all together and share the same Left/Right channel speakers, the AVR powers the center and surrounds. I keep them separate by using an integrated amp with a home theater bypass feature, so i use the AVR (Yamaha RX-A850) for TV, Blu Ray and ATV and use my Peachtree Nova integrated, Arcam DAC and microRendu w/ LPS-1 solely for 2 channel listening.

 

I base all my importance and upgrades at the moment on the 2 channel setup and want the music to be the best i can get it.

Behind my console that has my gear, i have 2 wall outlets, 1 outlet is on a dedicated 20A circuit and another is a common/shared outlet for the room. So...can i achieve the same great results with the iso transformer/power strip method with JUST the 2 channel gear plugged into it, i.e. Integrated amp, DAC, and LPS-1 for microRendu, and plug all of the other gear into the common/shared outlet?

 

In another room on the 2nd floor of the house is where my computer, modem and router are. I connect the microRendu with 15 meters of BJC CAT6A cable but there is also a network isolator in line, Emo systems EN-70HD, closest to the mRendu. The Router and modem are going to be plugged into a BK Precision 1604A isolator.

 

Here is how I was thinking i could hook this up...

 

2 Channel:

APC LE1200 > ISO Transformer/Simple power strip > Integrated amp, Arcam irDAC, mRendu/LPS-1, Sonos Connect

 

Multichannel:

2nd Wall Outlet > Power conditioner or Strip > Yamaha RX-A850, Subwoofer, Sony BRP, Apple TV3, LG OLED TV, Comcast Cable Box, 5 port Netgear Switch

 

I know that for now at least, the AVR and Integrated are connected with a pair of RCA's, however the AVR is OFF when i'm listening to the 2 channel setup. It's possible in the near future i might be replacing the Peachtree with another amp that may not have the HT Bypass feature, so the way i MIGHT install it is using a switch like the Niles SAS-1 which has a few ways of detecting a signal and i would run a pair of speaker wires from the AVR to the switch for the L/R ch only, and the same for the new integrated amp. The SAS-1 is auto sensing, it's adjustable and it works really well actually.

 

As i type this it kind of sounds like a big mess having all this gear together and trying to keep it 'separate', but i really don't have a choice. I refuse to use the AVR for music, it just doesn't suit me. If it ends up being a better choice to plug it ALL into a single iso transformer on the SAME strip than i would have at least 11 if not 12 pieces of gear.

 

Lastly, i didn't mention but is listed above, is the APC LE1200 voltage regulator, i bought a couple of these since they're so cheap and was thinking of putting one if both my main system and computer room.

 

THANK YOU for any help or suggestions in any facet of the above.

 

Mark

 

I'm sorry I'm rather frazzled right now, I'm packing up my house for a move and dealing with all kinds of financial stuff due to retiring. My brain is just not putting together a diagram of your system from reading the description. You are probably going to have to do this work yourself. It is not that hard.

 

First make a schematic drawing of your system, include all the boxes and both their AC power connections and signal interconnects between boxes. Make a bunch of copies of this and start tracing out possible leakage loops. Remember a loop goes through AC line, power supply of box, through interconnects to another box, through ITs PS to the AC line and back to the original box. You may have MANY such loops in a complex system.

 

The loop can go through any interconnect that has an electrical connection between boxes, including line level RCA interconnects, XLR interconnect cable, USB cable, S/PDIF cable, HDMI cable.

 

Then start assessing which loops are going to be most detrimental to sound quality. Loops going through the actual audio equipment are the most likely, so a loop through a DAC, preamp, poweramp etc are the most critical ones to look at. It's important to asses the amplitude of the loops, this is broken up into two primary issues, power supply type and impedance of the connections. Switching supplies (SMPS) usually have significantly leakage issues than linear supplies. Thus a loop going through two SMPS is going to have the highest amplitude, a loop going through two linears is going to be low amplitude and a loop with one SMPS and one linear is going to medium amplitude.

 

The impedance of the loop is also important. At very high impedance (ie "broken loop") no current flows, no loop, no noise from loop, this is the best, but hard to achieve. If you can't do that make the loop as low impedance as you can get, this cuts down on the noise generated by the loop.

 

The AC line is part of the loops, so decreasing the impedance of the AC line between boxes can help mitigate the affect on the sound quality.

 

A few examples: a very common situation is a computer with a USB connection to a DAC. This can be a very bad loop because the computer frequently uses a switching supply, AND is frequently on a different outlet or power strip from the DAC. Thus you have high amplitude from the SMPS and high impedance on the AC side of the loop. You can help this in several ways: put a linear supply in the computer, put the computer PS on the same strip as the DAC, or break the loop with an isolating device such as an intona or the upcoming ISO REGEN on the USB connection.

 

Hopefully this will give you some help evaluating your loops and where you think it would be good to decrease the AC impedance between boxes by putting them on the same power strip.

 

John S.

[asdf1000]

The AC line is part of the loops, so decreasing the impedance of the AC line between boxes can help mitigate the affect on the sound quality. A few examples: a very common situation is a computer with a USB connection to a DAC. This can be a very bad loop because the computer frequently uses a switching supply, AND is frequently on a different outlet or power strip from the DAC. Thus you have high amplitude from the SMPS and high impedance on the AC side of the loop. You can help this in several ways: put a linear supply in the computer, put the computer PS on the same strip as the DAC, or break the loop with an isolating device such as an intona or the upcoming ISO REGEN on the USB connection.

 

Hopefully this will give you some help evaluating your loops and where you think it would be good to decrease the AC impedance between boxes by putting them on the same power strip.

 

John S.

 

Hi John, very basic question here and I don't know if anyone has asked (or if it's too basic to be asked) but are the leakage loops the same as ground loops?

[One and a half]

Hi John, very basic question here and I don't know if anyone has asked (or if it's too basic to be asked) but are the leakage loops the same as ground loops?

 

Question is fine

 

Ground loops are traditionally associated with Ac mains sourced fundamental frequency that is 50/60 Hz.

 

How they propagate are the same fashion as for leakage loops the difference is only the content, can be multiple of the AC frequency to several Mhz, depending on how the source generates that frequency.

For sure leakage currents are of the ' conducted ' variety which travel through wires and are not picked up by an antenna effect, those frequencies are much higher.

[asdf1000]

Question is fine

 

Ground loops are traditionally associated with Ac mains sourced fundamental frequency that is 50/60 Hz.

 

How they propagate are the same fashion as for leakage loops the difference is only the content, can be multiple of the AC frequency to several Mhz, depending on how the source generates that frequency.

For sure leakage currents are of the ' conducted ' variety which travel through wires and are not picked up by an antenna effect, those frequencies are much higher.

Excellent, so any product that claims to break ground loops, will also be breaking leakage loops and leakage currents?

 

 

 

Sent from my Blackberry DTEK50 using Tapatalk

[Ralf11]

I'd say "no" based on this:

 

"a loop goes through AC line, power supply [of] box, through interconnects to another box, through ITs PS to the AC line and back to the original box. You may have MANY such loops in a complex system."

[JohnSwenson]

Hi John, very basic question here and I don't know if anyone has asked (or if it's too basic to be asked) but are the leakage loops the same as ground loops?

 

No they are not the same as what most people call "ground loops". The traditional ground loop is caused by differences in the voltage of the safety ground wire (the third pin in the AC plug). Frequently these are caused by the AC in the hot/neutral wires causing induction into the ground wire that is traveling along with them (in the three wire "romex").

 

Leakage loops are completely different. They are caused by leakage of the AC line (hot/neutral) through capacitances in the power supply to the DC output of the PS. They have nothing to do with the ground wire.

 

Both types of loops are primarily line frequency and its harmonics (50/60 Hz) so it is sometimes hard to tell them apart. It IS possible to have both types at the same time.

 

Traditional ground loops have been primarily seen in large installations such as live sound situations with a lot of distance between a stage and a mixer at the back of the auditorium. The length of the power wiring in the building can build up significant voltage differences in the safety ground. If there is electronics plugged in both at the front and back with a signal cable between them this causes the "ground loop" through the safety ground and the shield of the audio cable.

 

Leakage loops happen between power supplies, going over whatever path they can find between the DC output of the of the two supplies. BTW the leakage loop can happen over either + or -, but the impedance of the negative wire, through cable shields etc is usually much lower than the positive side. Since it frequently goes through the "ground" (ie shield) of the cable it is easy to get confused with a traditional ground loop. It IS possible to have both a ground loop and leakage loop going through the SAME shield on a cable!

 

John S.

[Superdad]

Just add to what John said, unlike with traditional ground loops--which are often detected by audible (low or high level) 50/60Hz hum--leakage loops do not typically result in any audible hum or buzz noise.

But when you begin to block or get rid of them--especially those coming from computers and accessories--sound quality can take a big jump.

Thus the raison d'être and effectiveness of the UltraCap LPS-1.

[One and a half]

Just add to what John said, unlike with traditional ground loops--which are often detected by audible (low or high level) 50/60Hz hum--leakage loops do not typically result in any audible hum or buzz noise.

But when you begin to block or get rid of them--especially those coming from computers and accessories--sound quality can take a big jump.

Thus the raison d'être and effectiveness of the UltraCap LPS-1.

 

Also Iso Regen

[asdf1000]

No they are not the same as what most people call "ground loops". The traditional ground loop is caused by differences in the voltage of the safety ground wire (the third pin in the AC plug). Frequently these are caused by the AC in the hot/neutral wires causing induction into the ground wire that is traveling along with them (in the three wire "romex").

 

Leakage loops are completely different. They are caused by leakage of the AC line (hot/neutral) through capacitances in the power supply to the DC output of the PS. They have nothing to do with the ground wire.

 

Both types of loops are primarily line frequency and its harmonics (50/60 Hz) so it is sometimes hard to tell them apart. It IS possible to have both types at the same time.

 

Traditional ground loops have been primarily seen in large installations such as live sound situations with a lot of distance between a stage and a mixer at the back of the auditorium. The length of the power wiring in the building can build up significant voltage differences in the safety ground. If there is electronics plugged in both at the front and back with a signal cable between them this causes the "ground loop" through the safety ground and the shield of the audio cable.

 

Leakage loops happen between power supplies, going over whatever path they can find between the DC output of the of the two supplies. BTW the leakage loop can happen over either + or -, but the impedance of the negative wire, through cable shields etc is usually much lower than the positive side. Since it frequently goes through the "ground" (ie shield) of the cable it is easy to get confused with a traditional ground loop. It IS possible to have both a ground loop and leakage loop going through the SAME shield on a cable!

 

John S.

Thanks John. Incredible detail. But for dummies like myself, does breaking a particular ground loop automatically break that same leakage loop too?

 

 

 

Sent from my Blackberry DTEK50 using Tapatalk

[Superdad]

Thanks John. Incredible detail. But for dummies like myself, does breaking a particular ground loop automatically break that same leakage loop too?

 

No, they are different as explained. You can break or reduce a ground loop and you will still have a leakage loop. All components with AC power supplies have leakage (that includes the linear power supplies in your amp, preamp, DAC, etc.; SMPS just put out a lot more it because of their required use of 'Y' capacitors for safety).

 

Let's look at an example that leaves aside computers, etc.:

a) Say you have a preamp and a power amp. They are both plugged into a "power conditioner" that has some unknown "filtering" (which typically dumps noise into the ground, but that's besides the point);

b) The preamp and amp are connected to each other by analog signal cables (single-ended or balanced, no matter);

 

So in the above, while there is a "loop" of chassis ground "around" them (the audio cables and their AC cords), you probably won't have any "ground loop" hum because their ground points (your "power conditioner" strip) are not far apart and there is not much being induced in them.

 

However, you still do have a leakage current loop, because you have two AC power supplied components joined by interconnects--and interacting with each other. And this is exacerbated by the fact that the "power conditioner" is increasing the impedance between the grounds of your preamp and amp.

 

As you can see, you don't have a ground loop, but you do have a leakage loop. And as mentioned, you are unlikely to know it because it does not manifest itself as hum the way ground loops do.

 

Which brings us right back to the topic of this thread and what John is espousing as a way to reduce leakage loops--while at the same time offer excellent blockage of surges and noise from whatever is on the house AC:

 

a) Build or use a power strip that has nothing but high-quality outlets and heavy gauge copper wire between them. Plugging ALL your components (or at least those that are contributing to any particular leakage loop) directly into this strip. This reduces the impedance between the components, thus reducing the effect of their leakage currents;

 

b) Plug that power strip into a Topaz (or one of its private labeled or successor brands) ultra-low-capacitance isolation transformer to provide your system with excellent protection.

 

 

Yes, this seems to fly in the face of all the power "filtering" and "conditioning" devices--some of them very expensive--which have been promoted to audiophiles for decades. But the results, for those who have gone this route--are outstanding.

 

----

In conjunction with the above--and partially an alternative/opposite approach--is to try to completely BLOCK the path of leakage currents by having near infinite resistance between both the supplies AND the interconnections between components. This is much more difficult--and not really possible to do just on the AC side with a power conditioner of any type.

But for devices--such as small DACs, peripherals, Ethernet renderers, USB converters and regenerators--that can be powered by a non-AC-connect supply (like batteries or our UltraCap LPS-1), they can be removed from the "leakage loops" and can be strategically placed so as to create a "moat" between the computer end (with its major leakage path along the USB cable) and the DAC end.

 

Of course the above area will be the focus of our forthcoming ISO REGEN, which, when combined with an LPS-1 will fully isolate and block the leakage path between the computer and the DAC. I did not start this post intending to end it with a product tease. I guess I am just stuck in a leakage loop of my own!

(I should be working on the ISO REGEN launch announcement text, so please don't ask questions about it here. Guess I am just warming up my fingers and writing brain and procrastinating in preparation...)

 

Ciao,

 

--Alex C.

[asdf1000]

No, they are different as explained. You can break or reduce a ground loop and you will still have a leakage loop. All components with AC power supplies have leakage (that includes the linear power supplies in your amp, preamp, DAC, etc.; SMPS just put out a lot more it because of their required use of 'Y' capacitors for safety).

 

Let's look at an example that leaves aside computers, etc.:

a) Say you have a preamp and a power amp. They are both plugged into a "power conditioner" that has some unknown "filtering" (which typically dumps noise into the ground, but that's besides the point);

b) The preamp and amp are connected to each other by analog signal cables (single-ended or balanced, no matter);

 

So in the above, while there is a "loop" of chassis ground "around" them (the audio cables and their AC cords), you probably won't have any "ground loop" hum because their ground points (your "power conditioner" strip) are not far apart and there is not much being induced in them.

 

However, you still do have a leakage current loop, because you have two AC power supplied components joined by interconnects--and interacting with each other. And this is exacerbated by the fact that the "power conditioner" is increasing the impedance between the grounds of your preamp and amp.

 

As you can see, you don't have a ground loop, but you do have a leakage loop. And as mentioned, you are unlikely to know it because it does not manifest itself as hum the way ground loops do.

 

Which brings us right back to the topic of this thread and what John is espousing as a way to reduce leakage loops--while at the same time offer excellent blockage of surges and noise from whatever is on the house AC:

 

a) Build or use a power strip that has nothing but high-quality outlets and heavy gauge copper wire between them. Plugging ALL your components (or at least those that are contributing to any particular leakage loop) directly into this strip. This reduces the impedance between the components, thus reducing the effect of their leakage currents;

 

b) Plug that power strip into a Topaz (or one of its private labeled or successor brands) ultra-low-capacitance isolation transformer to provide your system with excellent protection.

 

 

Yes, this seems to fly in the face of all the power "filtering" and "conditioning" devices--some of them very expensive--which have been promoted to audiophiles for decades. But the results, for those who have gone this route--are outstanding.

 

----

In conjunction with the above--and partially an alternative/opposite approach--is to try to completely BLOCK the path of leakage currents by having near infinite resistance between both the supplies AND the interconnections between components. This is much more difficult--and not really possible to do just on the AC side with a power conditioner of any type.

But for devices--such as small DACs, peripherals, Ethernet renderers, USB converters and regenerators--that can be powered by a non-AC-connect supply (like batteries or our UltraCap LPS-1), they can be removed from the "leakage loops" and can be strategically placed so as to create a "moat" between the computer end (with its major leakage path along the USB cable) and the DAC end.

 

Of course the above area will be the focus of our forthcoming ISO REGEN, which, when combined with an LPS-1 will fully isolate and block the leakage path between the computer and the DAC. I did not start this post intending to end it with a product tease. I guess I am just stuck in a leakage loop of my own!

(I should be working on the ISO REGEN launch announcement text, so please don't ask questions about it here. Guess I am just warming up my fingers and writing brain and procrastinating in preparation...)

 

Ciao,

 

--Alex C.

Thanks Alex! Nice and simple explanation that even a dum dum like me can understand! [emoji1]

 

Sent from my Blackberry DTEK50 using Tapatalk

[Speed Racer]

a) Build or use a power strip that has nothing but high-quality outlets and heavy gauge copper wire between them. Plugging ALL your components (or at least those that are contributing to any particular leakage loop) directly into this strip. This reduces the impedance between the components, thus reducing the effect of their leakage currents;

Alex (or any one else),

 

Do you know where I can buy a power strip like what your describe?

 

Thanks!

[JohnSwenson]

Alex (or any one else),

 

Do you know where I can buy a power strip like what your describe?

 

Thanks!

 

I like the Tripp Lite aluminum housing ones with just a switch and breaker. These are the PS series, there are many versions to choose from such as the PS3612.

 

These work well, are inexpensive and readily available.

 

John S.

[Speed Racer]

I like the Tripp Lite aluminum housing ones with just a switch and breaker. These are the PS series, there are many versions to choose from such as the PS3612.

These work well, are inexpensive and readily available.

John S.

 

Thanks, John!

 

I think I will buy the Tripp Lite PS2408RA or PS3612RA. These have right angle receptacles which make life easier with wall warts. I don't think I will need more 8 plugs so I am leaning toward the PS2408RA.

[sockpit]

Hi John or Alex. I own a small topaz and have benefited from this thread. Thanks! Can you give a brief lay explanation of how Topaz offers surge protection? Doesn't it put out what I takes in voltage wise?

 

 

Sent from my iPad using Computer Audiophile

[Bob Stern]

I own Torus Balanced Power RM45 BAL. 220 VAC input plus Ground (not Neutral). 3 independent output 120 VAC circuits.

 

The one shortcoming of Torus (Plitron) products is that the transformer has only one secondary, so there is no isolation between the devices connected to all those outlets.

[Superdad]

Hi John or Alex. I own a small topaz and have benefited from this thread. Thanks! Can you give a brief lay explanation of how Topaz offers surge protection? Doesn't it put out what I takes in voltage wise?

 

See post #3 from John: http://www.computeraudiophile.com/f27-uptone-audio-sponsored/discussion-ac-mains-isolation-transformers-started-w-posts-moved-linear-power-supply-1-troubleshooting-thread-30378/#post594376

[Superdad]

The one shortcoming of Torus (Plitron) products is that the transformer has only one secondary, so there is no isolation between the devices connected to all those outlets.

 

Hi Bob:

 

Well having equipment plugged into different isolation transformers (are there really isolation transformers with multiple secondaries?) is a different school of thought than what we have been talking about here (see my long post from earlier today).

 

Not that I am opposed to using more than one isolation trans--in fact I do just that to keep some gear separate. But doing so increases the impedance between the equipment plugged into the separate trans, and thus exacerbates any leak current loops between them. That may not be a problem if for example--as I do--the computer is on one trans AND there is full galvanic isolation on the USB line between it and the DAC/preamp on the other trans.

 

Again, I would be interested if you can point out any true isolation transformers that are wound with multiple secondaries.

 

All the best,

 

ALEX

[Bob Stern]

Alex:

 

The type of product I was thinking of was the API Power Wedge, which is several small isolation transformers with their primaries connected in parallel, rather than a single transformer with multiple secondaries.

 

However, I must confess that I stumbled into the tail end of this long thread and didn’t read John Swenson's explanation back in October of why AC power isolation between audio devices is counter-productive (except in the case you stated in which the signal ground references are galvanically isolated between devices). So I now see that the "shortcoming" I complained of is not a shortcoming at all!

[Speed Racer]

Alex,

 

If I have your ISO Regen (powered by an LPS-1) between my MacBook and my DAC, I don't want to put the computer or ISO Regen on the same power strip as the DAC, preamp, amps, etc., correct? Do I want them on a different circuit too?

 

Thanks!

[marksas3]

@JohnSwenson Thanks for taking time to provide some advice for my post above regarding having my equipment on different outlets etc. I will make a diagram as you said as a visual aid to help me sort it out.

 

In the meantime, i purchased a Kill-0-Watt meter and over the weekend plugged all of my equipment (12 devices or so) into 2 power strips and powered EVERYTHING up at the same time. Again this includes everything for TV/Movie watching to audio only gear.

I was surprise to find my readings to be lower than i expected. The Highest readings I got were from using my Yamaha AVR/Peachtree integrated amp combo for watching either cable TV or Blu Ray. As i stated previously, the Peachtree in this scenario is powering the front L/R channels while the AVR is powering Center and surrounds. A powered subwoofer also was in use.

 

At relatively high listening levels, or at least as much or more than I would ever use, (80-85 db) in my small room, the MAX readings were as follow:

 

VA = 260

Watts = 230

Pf = .88

Amps = 2.1

 

Considering that All of my equipment was powered on during this test, I felt comfortable enough to purchase an Iso Transformer like the one Alex @Superdad commented on, which is an ECA Extreme isolation transformer rated at 500va. I actually found an NOS on eBay still in it's box and packaging for about $160 shipped. I think it was a good find!

ECA ECA500 1 Extreme Isolation Transformer ECA500 | eBay

 

 

Mark

[skatbelt]

A question. I've been able to buy a 1KVA isolation transformer with very low interwinding capacitance. I am about to try it in the recommended setup with all my equipment connected to a minimalistic power strip. There is one problem however: my subwoofer is situated in another corner of the room and can't be plugged in that same power strip. The sub is connected to my amp by RCA. Is their a possibility to galvanically isolate a line level signal via RCA? Is there some kind of passive device that does this and if so, would it derogate the signal and/or create issues in the time domain?

[Ralf11]

Assuming no ground loops, what problem(s) arise from these leakage loops?

 

Is it noise injection into a DAC? or??

 

And what does the problem sound like?