Testing the PS Audio Noise Harvester.

Hello and welcome to whatishifi blog.

At the same time that we started messing with the PS Audio Quintet and the Power Plant Premier AC Regenerator, we also had several units of PS Audio Noise Harvester AC cleaner, a device that according to PS Audio collects line noise and converts it to light.


PS Audio Noise Harvester(s) waiting to be tested.

I might have created two separate posts for all these devices (the Quintet, the Premier and the Harvester), but actually the testing was done at the same period.

Regarding the Noise Harvester, the first test was again done at Pano's house. His electricity installation is a three phase with the Hi-Fi system solely connected at an ex fan storage heater power supply. Plugging the Noise Harvester at this outlet did not make the light blinking at all - meaning that the AC power is "clean". Nevertheless, we proceeded with the test.

We decided again to use the analogue front end, so we choose our favorite track, The Girl from Ipanema (Stan Getz / João Gilberto Featuring Antonio Carlos Jobim ‎– Getz / Gilberto, Verve Reissues / Quality Record Pressings / Analogue Productions B0015625-01). The test was blind, meaning one would plug and unplug the Noise Harvester at the Hi-Fi's power strip and the other one would listen. After several attempts, we understood that there was no sound difference. We assumed that this happened because the Noise Harvester could not find any noise to fix, so it couldn't offer any benefit. Just a moment before ending the test, we thought of searching in the house for an outlet from another phase that could be "polluted". Indeed, plugging the Noise Harvester at a kitchen's outlet caused it to blink; so we plugged at this outlet a power extension cable and we feed the audio system with this "dirty" AC power.

We started the blind testing again, but still there was no audible difference. Everything was sounding excellent with or without the Noise Harvester. We changed the recording; still the same. Puzzled that we might not be skilled enough to appreciate the improvement, we followed PS Audio's suggestion and we plugged multiple Noise Harvester but at a power strip with an on / off button that we connected to the system's power strip. By turning on and off the power strip with the 3x Noise Harvester plugged on it, we hopped to be able to spot a difference. We listened, listened and listened. Still, no difference. Zero. So, we called it a day and I returned home.


When we use the electric drill, the Noise Harvester array indeed turned on, but does this means they improve the sound?

The next day I continued experimenting. I plugged in the Noise Harvester at various outlets at my home, but it did not blinked; according to it, my AC is clean. I turned on my pre, power, AV amp, laptop, USB Audio Interface and the media player. No blinking. I turned on my Wi-Fi and LAN switch. No blinking.

Only after I turned on the TV or the projector I saw the Noise Harvester blinking. Good, I had the opportunity for some extra listening test at another system, so I invited Panos in order to verify the results.

In the meanwhile, I remembered that if I turn on my pre and power amps, select AV in but leave the AV processor off, when I turn on the kitchen's light (incandescent bulb) I hear a click noise from my speakers due to the switch. So I plugged in the Noise Harvester expecting it to eliminate this noise; well it didn't, neither did it blink. Not so good I would say.

When Panos came, we decided to make the listening tests at the (supposedly) noisy digital front end: the laptop and the USB audio interface, with the TV turned on. I am sure you guess the results; no difference.

Apart from these A/B tests, we also casually used a Noise Harvester at a third system. Sometimes we listened with it plugged in, sometimes without it. We never felt that there was any kind of sound improvement or difference.


Another system that the Noise Harvester made no difference.

As you might already know form this previous post, we also tested the Noise Harvester plugged in the Quintet and the Power Plant Premier. As I said, one of these devices seems not doing what it promises to do; the Noise Harvest kept blinking. It was only until we plugged it on the PS Audio P300 Regenerator (which is a true regenerator, composing it's output completely from scratch) that the Noise Harvest did not blink.



Only at the P300 the Noise Harvester did not blink.

The good thing about the Noise Harvester is that since it is a parallel device, it doesn't do any harm to the sound. The worst case scenario (and the most probable one, according to our experience with it) is that it will do nothing at all. Ok, who knows - there might be houses out there with an AC power so bad and with equipment so poorly designed regarding noise rejection that they might benefit from it, but I am skeptical about that. This is due to the fact that the Noise Harvester keeps blinking even when plugged to the PS Audio Power Plant regenerator; well it shouldn't, since these devises are supposedly giving clean AC power.

For us, it is just a device signaling that there is some noise at your mains but hey; as we saw this noise might not doing any harm to the sound quality.



The Noise Harvester blinking on the Quintet, not a good thing.



 Keeps blinking on the Power Plant Premier; this is really ugly.

So, no need for a Noise Harvester for us. Happy listening as always!

Christos

 

P.S. After I have written this post, at another forum another test with measurements was made; you can have a look here.