PS Audio Noise Harvester AC Cleaner Review

[amirm]

Have you thought about getting a LISN for tests like these?

Surge testing requires equipment that generates the high voltage pulses that UL requires. That is the bit that is expensive and at any rate, it doesn't relate to fidelity of AC mains. Is this what you were addressing?

 

[GXAlan]

I am afraid not. As I expected, he got grief from his subjectivist customers so not willing to have more stuff tested the way I have been doing.

Odd. The Accuphase is still one of the highest performing Class AB amps you've tested. It measures with more power than advertised. And as you point out, reliability is expected to be exceptional. Plus it's made in Japan with high labor costs, high material costs, and high shipping costs...

The idiosyncrasy is that Accuphase rightly or wrongly looks at balanced outputs as having more stuff in the signal chain, so with the exception of a handful of products, they work best with single-ended connections. Their rationale is that most people don't run cables long enough in the first place to benefit from balanced. Then, they generally run digital connections from their CD/SACD sources to their integrated amps.

 

[amirm]

Almost all of them have some kind of AC-"noise blocking" bevore the mains transformer,
nomally a smaller transformer and capacitors
Never marketed and advertised, never touted and scrapped in later players.
This kind of filterig is in a Sony-CDP-101 / 103 / Philips CD-304, Toshiba XR-Z70 and many more - what was it and why?

There is a Japanese electronics standard for AC mains filtering which many companies follow. In addition, such circuits are required to pass emissions tests. I showed this in an Onkyo teardown article I wrote a few years ago: https://www.audiosciencereview.com/forum/index.php?threads/inside-of-an-audio-video-receiver-avr.7/

I noted the same thing you did in the article.

 

[AndrewDavis]

There's definitely a market opportunity for clothes claiming to containing a Faraday cage. I wonder which companies will start selling Faraday hats first?

Somebody beat you to it. This is snake oil, too!


https://getlambs.com/products/emf-proof-beanie?utm_medium=cpc&utm_source=google&utm_campaign=Google Shopping&gclid=EAIaIQobChMI1Yee6Y6H6gIVdz2tBh2m1ARfEAQYASABEgKjIfD_BwE

 

[cjm2077]

Surge testing requires equipment that generates the high voltage pulses that UL requires. That is the bit that is expensive and at any rate, it doesn't relate to fidelity of AC mains. Is this what you were addressing?

You use other equipment to do surge testing. The LISN is just to insert a 50 ohm hookup into an AC line without disturbing it. I would use it with a spectrum analyzer to look at the noise on the AC line to see what we had to change in our AC filters or elsewhere to prevent conducted noise from the equipment I was designing from getting back onto the general AC. It's one of the most common UL tests to fail, along with radiated noise. At least when you're designing switching amps like I was. You are doing a pretty similar test, just looking at the incoming noise to the equipment from the AC instead of the other way around. If I were to create a setup for the test you were doing, I would have a given piece of equipment as a standard, hook the LISN in series, feed the output to the analyzer, and do a test with and without the magic noise reducer. You could vary the piece of test equipment from cheap to expensive like you have for the DAC output tests you were doing above, but I doubt it would matter much. Some of the noise will be from the line, some from the equipment, but that is always the story with a test like this.

(If you want we can talk about this outside the thread. Test methodology is probably not something best communicated in this format.)

 

[solderdude]

typical LISN for usage in EMC labs.

One can also use clamps for injecting and measuring pulses into wires or entire cables.

To inject you need a beefy generator to go with it... expensive.

 

[amirm]

You use other equipment to do surge testing. The LISN is just to insert a 50 ohm hookup into an AC line without disturbing it.

I know what a LISN is. You were responding to my statement about surge testing and hence my reply back to you that it doesn't solve the testing problem there.

 

[cjm2077]

typical LISN for usage in EMC labs.

One can also use clamps for injecting and measuring pulses into wires or entire cables.

To inject you need a beefy generator to go with it... expensive.

I was working with high power three phase devices for a bit, and we used a "Power Corruptor" to inject pulses, drop cycles, and do things like that.

I always wanted to start a rival company Absolute Power Corruptors. The motto: "We corrupt Absolutely."

 

[cjm2077]

I know what a LISN is. You were responding to my statement about surge testing and hence my reply back to you that it doesn't solve the testing problem there.

I was just replying to your last post before my first on the subject.

Edit: I was addressing your new "protocol" rather than the surge testing part. I guess that wasn't particularly clear.

 

[amirm]

I almost bought a different AC generator that would take a function generator input to create any waveform you wanted. But it was massive in size and weight so I opted for the BK. The BK can create chopped waveforms simulated dimmers and such but can't do arbitrary waveforms.

FYI as I have mentioned before, I also have an ancient PS Audio AC generator! I tested that a while ago and is as clean as my BK. But it is huge! And so heavy.

 

[mansr]

Uh oh - HiFi sounds better in Europe than in the states. I KNEW it!

Here in the UK, it gets really good when the mains reaches 250 V or more during times of low load.

 

[cjm2077]

It took two or three people to get the power corruptor on a cart. It was massive. Also three phase and could do 480 (I think, I only used it at 208), so obviously everything is scaled up.

 

[fieldcar]

Ah... The moment you realize you're in the right forum when everyone is talking about industrial electronics testing equipment.
Good company.

 

[restorer-john]

The idiosyncrasy is that Accuphase rightly or wrongly looks at balanced outputs as having more stuff in the signal chain, so with the exception of a handful of products, they work best with single-ended connections.

Their power amplifiers have been running fully balanced topologies for a number of years.

Their preamplifiers of the past (like practically everyone else) were already performing at the edge of what was possible with single-ended, so adding an opamp at the input or another inverted buffer at the output was certainly not going to improve anything. There's a rated 13dB difference between RCA and Balanced on my vintage Accuphase preamplifier with the RCA being 110dB and the balanced 97dB.

 

[Lotus78]

You guys are hard on Paul. He seems like such a nice guy. I will admit I would pay $100 for this if they would replace the LED with a mini lava lamp.

 

[mansr]

Looks can be deceiving.

 

[SKBubba]

You guys are hard on Paul. He seems like such a nice guy. I will admit I would pay $100 for this if they would replace the LED with a mini lava lamp.

You can get a lava lamp at walmart for $12. It would probably dissipate 10x-100x noise, because it is heated by an incandescent bulb.

 

[richard12511]

The electrical power generation/distribution industry is heavily regulated and by nature you are not going to get any significant harmonics to begin with. This product is for no purpose, worse than exotic audio interconnect cables, thought at least it costs only $99. Still, anyone who can think logically would spend that $99 on a decent DAC, that's if one can't stand to have an extra $99.

DACs are a waste of money too though, since they don't make any audible difference?

 

[mhardy6647]

If the LED doesn't dissapate enough power could we hook this up to a Tesla coil, or some other type of device? I would love an amp that periodically zaps and sparks- like something in Dr. Frankenstein's lab.

heck, or just a Xenon strobe instead of that wussy little LED.
Now we're talkin' night light.

 

[wwenze]

https://www.electrical-installation...standards#Maximum_permissible_harmonic_levels

Looks like AC mains is allowed to be as crap as they are.

For Singapore:

Spoiler

The owner of an installation shall ensure that the starting surges or harmonics generated by connected persons' and Transmission Licensee's equipment at the installation must not cause the maximum total harmonic voltage distortion at the point of common coupling to exceed the following:

At 400V and 230V, a total harmonic voltage distortion of 5.0 percent with no individual odd harmonic greater than 4.0 percent and no individual even harmonic greater than 2.0 percent

Add: The first link contains a page titled "Harmonics Filtering". That might actually do something measurable.