Isolation Transformer and Balanced Power versus PS Audio Regenerator

[Atmasphere]

Could you elaborate on that? I see that it flattens at the top, but isn’t that pretty typical of power from the utility?

No- that's a distorted waveform; flattened at the top suggests higher ordered harmonics are present. The waveform we have here at work looks a lot better than that!

 

[wil]

But the Harmonics bar graph shows nothing above but a minor amount at the 9th...

 

[Atmasphere]

But the Harmonics bar graph shows nothing above but a minor amount at the 9th...

I take it you're assuming that there aren't ones further up? Seriously its been a while since I've seen an AC waveform that messy.

 

[wil]

I don't know enough to assume anything. I'm just reporting what the Fluke 345 bar graph shows....

I'm not clear what you're implying. That the Fluke measurement is not to be trusted, or that there are higher harmonics at play above the shown 24th order?

 

[Atmasphere]

I'm not clear what you're implying. That the Fluke measurement is not to be trusted, or that there are higher harmonics at play above the shown 24th order?

I think you can trust it, but it doesn't look like it was designed for that display to have a lot of resolution.

 

[wil]

Could the resolution from the Fluke +/- 100 V be exaggerating the flat top relative to a resolution range, of for instance, +/- 400 V shown in the pic lifted from PS Audio?

 

[Robert Matthews]

I moved from an Isotek Titan to using a 7.5KVA balance transformer and 40A DC blocker. The improvement in bad ground silence, sweetness of sound, dynamics, etc. was very significant. I went for a large transformer, as I understand that distortion rises if the load exceeds 50%. Just the balance transformer was tried originally but I found I have DC on the line and it was really upsetting the transformer. The DC blocker solved that and made a HUGE improvement. I was staggered. The balanced transformer has the advantage in being able to also step down the voltage, as my mains is typical in the UK and is often approx 250+ volts. With the step-down, it's now typically 235 volts.

 

[microstrip]

The tricky question we should ask is why and how harmonic distortion of mains affects equipment performance. The AC mains is rectified , filtered and sometimes even regulated.

Long ago I have played a bit creating a 200W AC regenerator where I could easily control the amount of harmonic distortion - like the old PS Audio P300 multiwave. I used it with sources and preampliers but the results were inconclusive.

IMHO the critical parameters in mains are related to noise above the audio band , but it is just a guess, nothing else.

 

[Phillyb]

A video from Munich 2015 with Garth Powell, to get reacquainted to the fundamentals of AC noise treatment:

Garth is one heck of a salesman, he could sell Eskimo's ice.

 

[Atmasphere]

Could the resolution from the Fluke +/- 100 V be exaggerating the flat top relative to a resolution range, of for instance, +/- 400 V shown in the pic lifted from PS Audio?

I don't see how.

The tricky question we should ask is why and how harmonic distortion of mains affects equipment performance. The AC mains is rectified , filtered and sometimes even regulated.

If regulated then I expect less problems. But the 5th harmonic is known to make power transformers and rectifiers noisy; syncronous motors (like found in turntables and tape machines) can develop a counter rotational force opening them to being less speed stable. When you get noisy power supplies that noise can leak into audio circuits through a variety of means. While it may not manifest as a buzz in the speakers it may well manifest as additional IMD making for a less 'black' background and overall less musical presentation.

 

[rsrzr]

I never trust a review from a dealer that only recommends what they sell and bad mouth products they don’t sell.
The only way to tell what product is best for you, especially at $5k-$10k prices, is to audition them in your home with your equipment.
If you do purchase 1 of these units, you want to make sure they will handle the load your equipment requires. It would be foolish to hook up a 1000 watt monoblock amp to a psa premier device as well as hooking up a 3 watt amp to a psa p20

 

[ArnoFenn]

This topic links very well with this one:

Measuring power line capacity with the IDEAL SureTest, and the effect of Shunyata power products

First of all, thanks to @VLS again for introducing me to to the IDEAL SureTest 61-164 circuit analyzer https://www.amazon.com/Ideal-Industries-INC-Circuit-Analyzer/dp/B08NPPGKKW which retails for some $400 This device measures power line phase, voltage, impedance, leakage to ground, and peak...

www.whatsbestforum.com

And that package is what I have been working on/with for some time now.

The Ideal meausurement is useful to get the basics right, large diameter cable to the audio system and comparing power cords and selecting the better ones. It also reveals the best power lines if you're using existing ones.
For me, now that's a full stop for the purpose of the Ideal meter (Eye on "max peak (virtual/calculated) current" whether the system will ever need it or not.

Next there is the THD, Using the big fluke and staring at awful THD in voltage, worse THD in current and shocking current shapes. What to do with it and what is audible here. I did some trials, but don't try this yourself (with my EE background I did this in a safe way). I looked at the harmonics and the 5th was popping out. LC series calculations result in a notch filter that would drastically take out that fifth. I had the right HUGE and safe capacitor for this in combination with the approx value of the inductor. It worked and the 5th was almost gone. Next I listened to the the difference with/without and yes there is a significant difference, but since this was an experimental set up and drawing a significant amount of extra current shorting that 5th I don't use it at this moment.
There are professional THD reducing units available that even filter out most harmonics in a dynamic way (constant THD measuring and adaptive filtering these out)..huge expensive and mostly 3-phase. Not for now for me.

Third area, noise. THD is part of it but stretching the spectrum way up you might be looking at MHz and beyond. Filtering, two options, the in-line with LC etc but being in line it will increase the impedance of the power supply, good for noise reduction (as done to meet EMC requirements) but poor for high peak current demanding equipment.
The other way of filtering, seems like a free lunch, the Shunyata approach, apparent cables going through black boxes, assuming it's kind of piezo/HF-absorbing, might work, never saw spectrum measurements of this...but if this is a restriction of the noise, it is still a restriction in the power supply line.

The step I took to at least make a next step, big diameter cabling and a trial with a 3kVA balanced isolation transformer. Listening tests with/without....tremendous difference, better or worse? Well, without a doubt better with, blind tested and pointed out, my wife included. Measurments, EMI meter factor 5 reduction (if I remember correctly) on 1 meter and hardly a difference on the other.

For now, pause and enjoy the current configuration, however.....want to try the Furutech NCF plug with the expensive "Shunyata" similar approach in mind. Future, dynamic THD filtering and COSQ correction would be great but not for now..

 

[Kingrex]

Wil, turn all circuit breakes off in your house and take the measurement again. Is it severely distorted?

Then flip the breakers on one by one. Keep a log of all that disrupt the sine wave. When your done, what are the culprit.

If it does not change, start the process of engaging the utility to test their transformer. Show them the meter results. They may test their transformer and tell you its fine. It could be a neighbor. Is this reading in the middle of the day with a lot of AC running? Test it late at night or early morning when its cool out.

 

[wil]

Sounds like a plan! I suspect the culprit might be the small neighborhood water pump station which is located just one transformer away from the one closest to us.

If that's the case, I wonder what alternatives I have:

--maybe one or both of the transformers between us and the pump house is not up to the task? Ask utility to upgrade, if possible. Our low Power Factor (74) is probably costing us $ on our electric bill, no? (as far as PF goes, I can get it up to 90 by adding 300 watts of incandescent light bulbs and 95 by adding 500 watts.

-- battery powered audio? (color me sceptical).

Can you explain why the Voltage Sine Wave is being described as "terrible" and "a mess"? I see it flattens some at the peak. Is that not pretty typical?

Thanks

 

[Atmasphere]

There are professional THD reducing units available that even filter out most harmonics in a dynamic way (constant THD measuring and adaptive filtering these out)..huge expensive and mostly 3-phase.

A 'good' conditioner will do this without 3-phase.

Can you explain why the Voltage Sine Wave is being described as "terrible" and "a mess"? I see it flattens some at the peak. Is that not pretty typical?

No. If that is typical in your area you have an AC line noise problem.

 

[Kingrex]

I kind out doubt the pump house is the issue if it is on its own transformer. The 12480 utility power should have pleanty of tension to handle a well pump. But, do you have direct neighbors with solar or wind turbines?

Bad power factor is many times related to motors dragging it out of phase with the voltage. But adding the lights and having it return to normal is odd. It usually take capacitors to bring it back.

Perform the test I noted in #273 and let us know the results. I think I asked you in a private PM, do you have pools or an old AC/heatpump. Any large motors? Big old SubZero refer? Anything that could be impacting the power factor.

And what about your dimmers? Especially dimmers to Xenon under counter lights. You will find that out when you turn the breakers off.

 

[adyc]

Sounds like a plan! I suspect the culprit might be the small neighborhood water pump station which is located just one transformer away from the one closest to us.

If that's the case, I wonder what alternatives I have:

--maybe one or both of the transformers between us and the pump house is not up to the task? Ask utility to upgrade, if possible. Our low Power Factor (74) is probably costing us $ on our electric bill, no? (as far as PF goes, I can get it up to 90 by adding 300 watts of incandescent light bulbs and 95 by adding 500 watts.

-- battery powered audio? (color me sceptical).

Can you explain why the Voltage Sine Wave is being described as "terrible" and "a mess"? I see it flattens some at the peak. Is that not pretty typical?

Thanks

I thought TT7 provides PF correction?

 

[wil]

I kind out doubt the pump house is the issue if it is on its own transformer. The 12480 utility power should have pleanty of tension to handle a well pump. But, do you have direct neighbors with solar or wind turbines?

Bad power factor is many times related to motors dragging it out of phase with the voltage. But adding the lights and having it return to normal is odd. It usually take capacitors to bring it back.

Perform the test I noted in #273 and let us know the results. I think I asked you in a private PM, do you have pools or an old AC/heatpump. Any large motors? Big old SubZero refer? Anything that could be impacting the power factor.

And what about your dimmers? Especially dimmers to Xenon under counter lights. You will find that out when you turn the breakers off.

If the pump house is at the end of the line of transformers, and it has it's own transformer close by, does that mean that it is isolated from the transformer close to our house (second from the last) and so not affecting our transformer? Or is each transformer in the series of transformers affecting all within the circuit?

That water pump station is the only thing I'm aware of nearby that could be affecting us. But I will certainly test to eliminate any possible factors here.

 

[wil]

I thought TT7 provides PF correction?

I think so too, but I want to confirm that. I would like to be able to measure after the TT7, but I don't know if there's any way to do so with the Fluke 345 clamp meter I have access to.

 

[microstrip]

101.4% THD? really? If that is really right I'd guess there's a power transformer badly overloaded somewhere upstream.

The 101.4% THD is probably a particular current spectra measured with the clamp, not the voltage. I shows a full rectifier action. The voltage spectra and its THD were shown in the first figure.

Disclaimer - I have never used this particular device and we do not know how the measurements were carried - this is just a suggestion!