This is a review and detailed measurements of the AudioQuest PowerQuest 3 Power Conditioner, Non-Sacrificial Surge Protector and Power Strip. It was purchased new and kindly drop shipped to me by a member. It costs US $300 from Amazon including Prime shipping.
OK, power strips don't have to be pretty but this is one big, ugly, heavy, plasticy power strip:
Granted, there is some goodness in having widely spaced receptacles that are duplicated on the front as on the face. And heavy weight helps keep it in place.
I like the non-destructive surge protection as typical surge device degrades with use and eventually can die in catastrophic manner (think smoke). There is an over voltage protection here as well (anything above 140 volts). I am not here to test these capabilities however. The focus is on the improvement in audio as claimed:
The outlets are specialized in that there is a pair for high-current devices, two for general audio, and a single one for 4K/8k video device. How you optimize a power strip for resolution of a display is beyond my pay scale.
Power Conditioner AC Measurements
I still can't find my darn differential probe so had to resort once again to using a step-down AC transformer (same one that came with the JDS Labs Atom DAC) to bring the voltage to something reasonable that doesn't destroy my audio analyzer. Here is the spectrum of AC where I plug in my analyzer and all the audio devices I test, as compared to the high-current outlet in PQ3:
The first spike is at 60 Hz and that is all we want. Alas, we also get a boatload of other harmonics and noise products continuing on to the end of the 90 kHz bandwidth of this test.
Alas, the PQ3 has no effect on any of this unwanted energy. All the noise is coming through at very high amplitudes to boot. We are talking forth harmonic that is just -32 dB lower than 60 Hz. Yet our electronic devices manage to produce distortions that are routinely -110 dB or better. How do they do that? They do their own filtering which is a heck of a lot easier and cheaper to do on a 5 volt DC signal than 120 volt AC.
OK, high current outlets typically don't have filtering in these devices so let's move to the middle outlets which are for audio devices and see what we get:
All the junk in audible band remains exactly the same. There is however filtering above 30 kHz. If you look at the fine print in the spec as I have shown on the graph (top right), company says the same thing. So our measurements are correct and prove that no audible frequency noise or distortion is removed by PQ3!
As to the 4K/8K video outlet, I find no difference between it and the outlet above:
Note that if your display did not filter out the junk above 60 Hz already, the image would be terrible. The fact that it is pristine, and blacks are black in an OLED display, it indicates that it is of no need of further filtering.
Power Conditioning Effect DAC Measurements
Ultimately we listen to the output of an audio product, not what goes into it as far as mains power. So let's use our most sensitive test that brings out all spurious noise and jitter to see how the output of the JDS Labs Atom DAC varies with and without PQ3:
There is no real difference no matter how much you squint. Spurious tones at 1 kHz and harmonics remain (like USB packet noise). Tiny spurious tones do too despite having levels at whopping -145 dB. This is past the best case -- never seen in real life -- performance of 24 bit audio (no room temperature DAC or electronics can get down to 24 bits).
We could test many more devices but the results will be the same. As I mentioned at the outset, this is the outlet I use to test all audio devices and the fact that we see spectacular performance proves that we don't need to prefilter the AC mains.
Conclusions
It is clear that the PowerQuest 3 does nothing for our audio performance. I am confident the same is true for your video device. So the claims there completely unjustified.
On surge protection though, there is some value add in what seems to be an absorbing type device (series?) and over voltage protection (although its response time may be too slow to do any good). For this reason, I did not give the PQ3 the worst score I could.
As an audio and video improving device, I cannot recommend the AudioQuest PowerQuest 3. Only buy it because you need some of the other things it does, or its form factor.
------------
As always, questions, comments, recommendations, etc. are welcome.
It never ends. The pink panthers are now complaining that they are tired of posing "in the nude" and want me cloths them for pictures. I don't know where you get outfits for them but assuming I can find a source, I need the money. So please donate what you can using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
OK, power strips don't have to be pretty but this is one big, ugly, heavy, plasticy power strip:
Granted, there is some goodness in having widely spaced receptacles that are duplicated on the front as on the face. And heavy weight helps keep it in place.
I like the non-destructive surge protection as typical surge device degrades with use and eventually can die in catastrophic manner (think smoke). There is an over voltage protection here as well (anything above 140 volts). I am not here to test these capabilities however. The focus is on the improvement in audio as claimed:
The outlets are specialized in that there is a pair for high-current devices, two for general audio, and a single one for 4K/8k video device. How you optimize a power strip for resolution of a display is beyond my pay scale.
Power Conditioner AC Measurements
I still can't find my darn differential probe so had to resort once again to using a step-down AC transformer (same one that came with the JDS Labs Atom DAC) to bring the voltage to something reasonable that doesn't destroy my audio analyzer. Here is the spectrum of AC where I plug in my analyzer and all the audio devices I test, as compared to the high-current outlet in PQ3:
The first spike is at 60 Hz and that is all we want. Alas, we also get a boatload of other harmonics and noise products continuing on to the end of the 90 kHz bandwidth of this test.
Alas, the PQ3 has no effect on any of this unwanted energy. All the noise is coming through at very high amplitudes to boot. We are talking forth harmonic that is just -32 dB lower than 60 Hz. Yet our electronic devices manage to produce distortions that are routinely -110 dB or better. How do they do that? They do their own filtering which is a heck of a lot easier and cheaper to do on a 5 volt DC signal than 120 volt AC.
OK, high current outlets typically don't have filtering in these devices so let's move to the middle outlets which are for audio devices and see what we get:
All the junk in audible band remains exactly the same. There is however filtering above 30 kHz. If you look at the fine print in the spec as I have shown on the graph (top right), company says the same thing. So our measurements are correct and prove that no audible frequency noise or distortion is removed by PQ3!
As to the 4K/8K video outlet, I find no difference between it and the outlet above:
Note that if your display did not filter out the junk above 60 Hz already, the image would be terrible. The fact that it is pristine, and blacks are black in an OLED display, it indicates that it is of no need of further filtering.
Power Conditioning Effect DAC Measurements
Ultimately we listen to the output of an audio product, not what goes into it as far as mains power. So let's use our most sensitive test that brings out all spurious noise and jitter to see how the output of the JDS Labs Atom DAC varies with and without PQ3:
There is no real difference no matter how much you squint. Spurious tones at 1 kHz and harmonics remain (like USB packet noise). Tiny spurious tones do too despite having levels at whopping -145 dB. This is past the best case -- never seen in real life -- performance of 24 bit audio (no room temperature DAC or electronics can get down to 24 bits).
We could test many more devices but the results will be the same. As I mentioned at the outset, this is the outlet I use to test all audio devices and the fact that we see spectacular performance proves that we don't need to prefilter the AC mains.
Conclusions
It is clear that the PowerQuest 3 does nothing for our audio performance. I am confident the same is true for your video device. So the claims there completely unjustified.
On surge protection though, there is some value add in what seems to be an absorbing type device (series?) and over voltage protection (although its response time may be too slow to do any good). For this reason, I did not give the PQ3 the worst score I could.
As an audio and video improving device, I cannot recommend the AudioQuest PowerQuest 3. Only buy it because you need some of the other things it does, or its form factor.
------------
As always, questions, comments, recommendations, etc. are welcome.
It never ends. The pink panthers are now complaining that they are tired of posing "in the nude" and want me cloths them for pictures. I don't know where you get outfits for them but assuming I can find a source, I need the money. So please donate what you can using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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like from Class D amplifiers or switching power supplies or even nearby cell phones. I'm not sure how any recommendation should be given, Amir, for its primary function of surge protection, unless that is tested. You can't assume anything these days 
