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Does the PS Audio noise harvester really work?

  • Yes, I own it and it works great!

    Votes: 2 100.0%
  • I own it but have not noticed any effect.

    Votes: 0 0.0%
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Mine are on their way - should be here in a couple of days.
A couple of us are going to try them out in different properties and see how they work. I'll feedback the results.
 

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They arrived today and plugged in - flashing like crazy on some circuits and slow flashing on others, so there's something going on.
Already have an idea on how they affect the sound but will post feedback after more prolonged listening tests.

NB
I'm OK with the vote based on pollers trying the Harvesters out, but feel its unfair to vote based on opinion, predjudice etc. It' s unfair on the manufacturer and just an opinion to vote with no experience, and adds no value.
 

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I've spent the last few days staining my deck and just reassembled my system - I wanted to try the Harvesters with my Richard Grey.
When I first plugged 3 into a group of outlets they all flashed at a similar frequency, the last 2 went into a seperate group of outlets and flashed at a lower frequency. Being a sceptic I thought that maybe PS Audio tunes them in the factory to flash at a pre-determined frequency to fool us into believing we had 'noise' in the supply. I swapped them over and confirmed that they are not pre-set.:rolleyesno:

I'll need a few days to recover from them strobing at me all day, and give them a fair trial. I also will have a friend come over for the blind trial, to eliminate the 'these cost $400 so they must do something' syndrome.
 

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Harvesters - Initial Impression

I've had my system offline for the last week and a half waiting for a new 3 channel amp to arrive, I noticed that during this time I wasn't completely happy with what I was hearing so wanted to reinstall everything before giving the Harvesters a fair crack of the whip. The key component missing was my Richard Gray RGPC1200, don't know what it does but my system is sweeter to listen to with it in place. And from this reference point it was the right environment to give the Harvesters a workout.

Equipment used:
Modwright Sony NS999ES CD/SACD/DVD player
B&W N803 speakers
Musical Fidelity KW500 integrated amp
Richard Gray RGPC1200

Under test:
5 PS Audio Harvesters

Tests disc used:
Steve Reid - Bamboo Forest
The Coors - Talk On Corners
Sweetbottom - Live The Reunion
Seal - IV
Alan Hull - Pipedream

I plugged the Harvesters in different locations in my HT room, which has two seperate 20amp circuits, and did see the Harvesters flashing away at different frequencies in different locations at different times of the day. The discs chosen are ones that my local buddy Lou (free plug for his jazzsite http://www.contemporaryjazz.com/) and I use to get a first impression of a piece of equipment. These discs (except for Pipedream, which is one of my old favs) are very revealing and can quickly give an indication of soundstage, male and female vocals, instrument separation and 'musicality'.
First impression with 1 Harvester plugged in - no significant change, all 5 Harvesters - no significant change.
By no significant change I'm talking about a 1-3% difference with and without them, which at $400 does not represent for me a good price performance equation. In addition the 1-3% range is in the land of 'psycho acoustics' or 'I thought I heard something'.
The next step is to give them a week in my system to see if the change is subtle, and finding out what changes take place after getting used to them . I will then go over to Lou's place to try them in a different environment, and report back.

I had planned to wait until the Harvesters had been in my system, and at a second location before posting: but decided to post an interim report as their is a lot of interest. With this in mind the final verdict isn't in yet - so please bear this in mind before drawing any conclusions.
Acid test, will I keep them? The jury is still out:dontknow:
 

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These are basically filters to create a load at frequencies other than the line frequency and dissipate The problem that I see with them is that there is a lot of noise in electrical systems that does not effect problems with sound nor pix in most systems. Some systems may have problems that do affect the sound or pix, but most do not. I have done lots of experimenting to try to find what kinds of line noise is actually visible in video systems and found that in most video components, the power supplies eliminate most problems with line noise. Ground loops are another matter. With audio systems, there is more liklihood of a.c. noise creating a problem but it is relatively rare.

Consider how most video components power supplies operate. Most use a switching supply that takes incoming a.c., rectifies it (as does a conventional power supply) to d.c. and filters it with relatively large capacitors(though nothing like the capacity in a typical audio amplifier, maybe 680 uF). At this point it could still have a fair amount of noise on it and more likely significant ripple. That d.c. with noise is then switched on and off at a rate of perhaps 50-125 khz. This switched d.c. looks like a distorted square wave that is input to the primary of a transformer, inducing a current in the secondary. This current is rectified, typically by high speed or barrier diodes and fltered using caps approriate for the load. Typically there are multiple filter caps and multiple supplies on the secondary at different voltages. More regulation is applied on most supplies, folowed by filter caps on those lines.

The bottom line is, in most video components that work this way, it is nearly impossible for low level noise on the original a.c. to survive the several stages of rectification, switching, and filtering. More conventional power supplies typically used in audio components are more likely to allow low level a.c. noise to pass, but also do a pretty good job of filtering it.

Devices like the PS filters are likely doing something. The question is whether it is of value and whether it represents a value to the user. I suspect that in most cases it does not. In some rare cases there may be noise that they might affect. I would be interested in the conditions that might make such devices useful.
 

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it is nearly impossible for low level noise on the original a.c. to survive the several stages of rectification, switching, and filtering.
Exactly.

Phil, I'm pleased to see you've remained neutral and have an open mind about the efficacy of the Harvester. I'll offer an opinion.

I have to give kudos to PS Audio for their marketing ability with this product. Devices that don't have moving parts need some sort of visual boost to let the user know that it's working. What better than a flashing light and reciting the law of conservation of energy to prove the job's being done.

AC line filtering is a well understood science. There's nothing new in that department. The tried an true method of EMI/RFI noise filtering is to employ a low pass filter made up from a series/parallel ladder of inductors and capacitors that attenuate and bypass high frequencies, so as to restrict them from arriving at your equipment. They do a good job, although most electronics equipment in your system have very high EMI/RFI noise rejection already built in. The power supply transformer, bypass capacitors, filter capacitors, voltage regulators and the chips themselves all provide a high frequency noise rejection that could easily be as much as 100dB from line cord to chip. The assumption that we even require filtering is overstated.

I'm sure the Harvester is a fine parallel filter and works as advertised, although detailed claims are absent. The Harvesters parallel impedance (frequency dependant resistance) will lower for high frequencies and be insignificant at 60Hz just like any other simple parallel two lead filter. The high frequency energy will be diverted to a capacitor and then some electronic arrangement will fire the light until the capacitor is suitably discharged. A typical parallel filter will divert the energy to the neutral line. Both methods are effective, although it's really better to provide a combination of series and parallel filtering such as a power conditioner will possess. Note PS Audio agrees with this conclusion since they recommend a standard series/parallel conditioner also to be used in conjunction with the Harvester.

Most EMI/RFI filters provide insertion loss tables so you can choose the size you want to employ. If I look at the filter I use in my own system it spells out all the necessary specifications to understand what the device does in the circuit. I use a standard CORCOM V-series 30 amp line filter 30VK6. It uses a tried and true impedance ladder shown below with associated specifications on insertion loss.



This tells me a lot.
I know what this filter is going to do before I use it.
Would I buy it without the specifications - no.


Here's the marketing hype from PS Audio on their product.

Code:
Here’s the dirty little secret none of our competitors want you to know.  
ALL power line filters - regardless of design – do not actually eliminate noise from the power line.
Instead, they only shift the noise around from one place to another!

So noise that comes in the hot side of the line may be sent over to the neutral or ground side.  

But it most certainly is NOT removed or reduced.  Even so, there is nearly always SOME benefit.  
Just not all you paid for.

Physics 101

Energy can neither be created nor destroyed.  
Unless we choose to ignore it, we only have two choices:
  
It can be rerouted or it can be converted to another form of energy.  
It cannot be destroyed as some marketing materials might suggest.

So let’s assume we definitely want to eliminate the noise, 
not just hide it somewhere where it can still cause trouble.
Seriously, whether we divert the noise to neutral and ground or turn on a light bulb, it matters not.
What's important is that it doesn't arrive at our equipment. I would have rather seen a spec sheet on the Harvester rather than lesson 101 and then we could have decided how well it worked before purchase.
As I said before, this is a well understood principle - no magic here. :)

brucek
 

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Phil, thanks for the feedback on the Harvesters. You were honest and candid about what they did in your system without bashing the possibility they may work in someone else’s system.

Hey Bob, I ain’t no Zealot, just one of Phil’s peeps. :hail: to Phil :hail: to Phil :hail: to Phil...LOL

Leonard and BruceK, thank you for the electricity / physics 101 stuff…my head is still spinning over what you two wrote.

What I want to know is how a device can work when your electronic gear isn’t plugged into it. Yes, I have had adverse experiences (added noise into the line) with a light dimmer that was wired in the same circuit breaker feed as my audio gear. However, I just can’t get my brain to wrap around the concept of these devices having a favorable impact with something on the same line or in the same house instead of my gear being plugged directly into it (like a conditioner or suppressor). I remain cautiously interested and await Phil’s trial at his friend’s house.

Speaking of the “Great One's” friend…Phil, would you care to share with us the jazz cds that he has recommended to you to use for testing out your equipment?

Thanks,
Laserman
 

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Laserman,

Jazz CD's - Diana Krall, The Girl In The Other Room is one of the favorites for vocals and bass - I'm just a simple Floyd, Zeppelin, Yes guy! I'll get a list from Lou, he's a lurker here but can give me a list to post for promoting his site.

Give me another week with the Harvesters, Lou is more critical than I am and calibrates me if I think I'm hearing something - normally its a slap on the head:huh: At least PS Audio let you try them in order to see if they work in your environment, so they're worth a try.

I'm shocked that I missed my Richard Gray, this was going to go on Audiogon to generate some $ for new toys, its definetly a keeper. I've had it for 3 years and didn't think it did much except take up rack space, it takes out some of the harshness.

Regarding the electronics 101 lesson we received - its confused me also:scratch:

Finally, you can cut out the Great One stuff, Your Majesty works just fine :hail:
 

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laserman said:
What I want to know is how a device can work when your electronic gear isn’t plugged into it. Yes, I have had adverse experiences (added noise into the line) with a light dimmer that was wired in the same circuit breaker feed as my audio gear. However, I just can’t get my brain to wrap around the concept of these devices having a favorable impact with something on the same line or in the same house instead of my gear being plugged directly into it (like a conditioner or suppressor).
The device is parallel in the circuit just like the MOVs in a surge suppressor. Like those MOVs, they only allow current to flow through the device when certain conditions are met. In the case of a filter, the conditions are that energy exixts at the right frequency, which is not the frequency of the a.c. power. In the case of MOVs in a surge suppressor, it depends on the voltage. Your electrical system in your home has lots of things in parallel, like that dimmer.

A good analogy would be room damping devices that absorb certain frequencies. They are not part of your speaker system but still have an effect.

The question, IMO, is not whether it is possible for a parallel device to affect the circuit, but whether the effect is meaningful.
 

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laserman said:
Speaking of the “Great One's” friend…Phil, would you care to share with us the jazz cds that he has recommended to you to use for testing out your equipment?

Thanks,
Laserman
In addition to the cd's I mentioned Lou suggests these:

Spies - self-titled
Patricia Barber - live , a fortnight in france
Diana Krall - the look of love
Shapes - the big picture
Flim & the BBs - big notes
Bob Mintzer - art of the big band

These cds are recorded/mastered very well and the music writing and arrangements are fantastic.

As jazz has got so many sub genre's you might want to check out the website I mentioned in a previous post:
contemporaryjazz.com
The guy's there can help out with a more detailed list.
 

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Flim & the BB's - Big Notes... awesome! One of my favorites!

So is the verdict still out on the Harvester Phil?
 

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Well Sonnie I want to give them a fair trial, so I'll just keep them installed for another week and then remove them and see if I miss them or not. Also they're going for a field trip to Big Lou's, that will give another data point.
So the jury is still out:dontknow:
 

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Phil, thanks for the jazz recommendations (I guess it is Lou I should be thanking). I sampled most of them and ordered them from half.com and amazon. Great music for sure and I can't wait to hear how they sound in my system. :T

Thanks again and I too am waiting on a follow-up on the harvesters after your road trip to Lou's. :drive:
 

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laserman said:
Thanks again and I too am waiting on a follow-up on the harvesters after your road trip to Lou's. :drive:
He's enticed me with food tomorrow lunch time, he knows my weakness. So I can feel a review session coming on.:eek:
Based on the thumbs up on the Film & The BB's I too listened to the Amazon demo's and bought it from half.com (we probably bought the same copy:laugh: )
 

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So I can feel a review session coming on
I'll propose a test for the Harvester.

Remove his line conditioner and test the Harvester by pressing your ear on a tweeter and check the noise floor with and without it.

Then plug in his conditioner and perform the same test.

I suggest you'll notice a small difference on test #1 and no difference on test #2.

brucek
 
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