Testing the PS Audio Quintet Power Center & Power Plant Premier AC Regenerator, thrice.

Hello and welcome to whatishifi blog.

I was lucky enough to get in hand two components that promise to improve the AC that we feed to our beloved Hi-Fi equipments: the passive PS Audio Quintet and the active PS Audio Power Plant Premier that regenerates the AC power.


From top to bottom: PS Audio Quintet Power Center & Power Plant Premier AC Regenerator.

Up to now, if you are a regular reader of my blog, you know that I have experience with two other similar devices: the active ExactPower EP15A and the passive Audio Agile Line power strip. The ExactPower was a mixed emotion; I never reached a definite conclusion regarding if the system sound benefited from it's presence - which means I didn't need it. The Audio Agile was another thing, as I said at this older post before testing it I was laughing to the idea that a power strip would improve the sound but after some listening I shut my mouth and got two units that are still in my system.

I have also tested an isolation transformer; it didn't made any improvement and after noticing that just a 100 Watt light bulb load would cause around a 1 VAC drop in it's output , I understood that I better keep it of the system.

Anyway, let's proceed with our new fellows, starting with the Quintet. The EU version of Quintet offers 5 schuko sockets. It can be described as a power strip that performs passive filtering and offers surge and spike protection, but it is not only that. First of all, the build quality is excellent. Second, it does offer some power management with the aim of trigger signals. On the left of the device, there are three switches and two trigger inputs. Each switch has three positions: ON (always power on the outlet) SW (switched, the outlet will give power only when the Quintet receives a trigger signal) and DLY (delayed, the outlet will give power 3 sec. after the Quintet receives a trigger signal). The DLY is very useful when for example you want your power amp to turn on last, in order to avoid getting any clicks from sources turning on or stabilizing. So, each switch controls a different set of sockets: the first switch controls the first two sockets, the second switch controls the 3rd and 4rth socket and the third switch controls the last socket marked as "Power Amp". This "Power Amp" socket is not different than the other four, PS Audio says it has marked it so for convenience but I have to add that plugging the most energy hungry device at the last socket is the right thing to do; you should start with the most sensitive device and then gradually proceed to the most heavy one. So, for example, the right way to plug your system is this: start from the phono amp, then the pre amp, then the power amp.


The trigger switches and the LAN / antenna in & out of the PS Audio Quintet.

If you have no trigger commands but you still want to make use of the SW or DLY functions, you can do so by pressing the logo that is at the left of the device. This logo is actually an illuminated switch that controls the sockets - the same way a trigger signal would. So, if all the switches are left to the ON position, it doesn't matter what you do with this logo-switch. If you put a switch at the SW position, then the corresponding sockets will be slaves to this logo - switch.

The Quintet will also protect your equipment from spikes, undervoltage and overvoltage. This protection is passive, meaning you don't have to worry that it adds components in series with the power feeding your equipment, so supposedly it won't "choke" the sound or restrict the dynamics.

The surge and spike protection lies at the AC inlet module - it is where you connect the power cable - and this module can be replaced in case of malfunction. Protection includes TV / SAT / LAN signals, there are in and out plugs for all of these.

Also, there is some filtering going on. This includes filtering the AC mains that feed the equipment but also isolating one equipment from another; in case for example you have a nasty device with a switching PSU that creates noise, this noise will be isolated and will not be "seen" at the other sockets of the Quintet. That is why at the UK plug version of the Quintet where the sockets are double, you should group similar equipment together at the same zone, for example digital equipment like a BD player and a laptop should be plugged at the same socket twins.

As I said, build quality is exceptional and the device is beautifully finished. A simple power cord is included and PS Audio suggest that you invest at a more sophisticated one with thick wires and efficient shielding.

Moving on to the Power Plant Premier AC Regenerator things are different, meaning that we move on from a passive to an active component. The Premier will actively try to output a perfect waveform by intervening only at that part of the waveform that needs fixing. That means that a part of the initial waveform will be kept and this limited intervention is the reason that this device can support even a power amp. The efficiency rating is 80% and is considered to be a good one. However, I find the term "Regenerator" a little misleading here; this term suits better the older P300 that completely regenerates the power from scratch. The Power Plant Premier has a wave shaping approach, like the Exact Power EP15A.


The back of PS Audio Power Plant Premier AC Regenerator

So, everything that was present at the Quintet (triggers, isolation zones, etc.) is also present here in the same way, with the addition of the AC regeneration and some other tricks under the name of MultiWave and CleanWave. According to PS Audio: "In the MultiWave position, the peak charging time of the sine wave is extended to help connected equipment lower power supply ripple and therefore improve the performance. MultiWave can have the same improvement gained from adding a larger power transforme ror more power supply capacitance to connected equipment". Also, "CleanWave places a series of higher frequencies that ride on the main sine wave to help "degauss" connected magnetics".

The Premier is remote controlled and has a display that can be dimmed or turned off. At the display you can see the ACV in, ACV out, THD in and THD out. Like the Quintet, the build quality is exceptional and the device is beautifully finished. The two internal cooler fun that is has are almost noiseless and did not destructed us at all.

But enough with the description, let's move on to the juicy part which is the listening test. I brought both devices at Pano's house where plugging and unplugging the power cords is a much simpler task than in my system.

The PS Audio Quintet is connected to our system - or should I say our system is connected to PS Audio Quintet.

We started by listening our favorite "Girl from Ipanema" (Stan Getz / João Gilberto Featuring Antonio Carlos Jobim ‎– Getz / Gilberto, Verve Reissues / Quality Record Pressings / Analogue Productions B0015625-01) without connecting any of the PS Audio devices  in order to refresh our memory regarding how the music feels and sounds. Then we added the Quintet to the equation; we plugged on it the custom phono preamp, the custom preamp and the Parasound A21 power amp. We took care to plug them with the right polarity, as described at this older post. To be honest, we were afraid that we would struggle to hear any differences but that was not the case. The soundstage opened up immediately. Unfortunately, there were some side effects also: we felt like a magnifying glass came to magnify things that did not need magnification. The high frequencies and the small details were increased without becoming harsh, however they did not need to be increased. Also, some of the magic that the sound engineer Mr. George Marino has put at this wonderful recording disappeared, making it sound a bit "naked" and aged. We moved on with Dire Straits, we listened with the Quintet connected to the system, then we plugged everything back to the standard humble wall socket and we listen again. Dire Straights were sounding better without the Quintet which seemed to add some kind of irritation to the sound of the electric guitars.


The PS Audio Power Plant Premier AC Regenerator feeding the system.

We moved on with the Premier Regenerator. Since the mains tester screwdriver lightened at both sides of the output outlets, I thought that the Premier had balanced AC outputs, meaning that instead of having one hot (230V) and one neutral (0V) lead, you have one with +115V and one with -115V. That would mean that there is no "correct" orientation for plugging in the power cords. But as we found latter, my balanced assumption was wrong - but stay with me, we did the same test with the power cord of the connected devices plugged in with the "right" orientation.

An interesting thing is that the Premier has it's own power cord polarity, so there is a "correct" way of plugging it in to the mains socket. For peace of mind and without being sure if it matters, I would plug in the Premier the "correct" way - I am sure that it doesn't make any harm. Maybe one day Paul from PS Audio will make a video about this.

What I found a bit strange is that in Pano's house the AC V is 218 Volts (ah, Greece 2018, I live 5 minutes away and I have 235 Volts) but the regenerator instead of increasing this, it claimed outputting 213 Volts. I would expect it to give at least 220V - ideally 230V - but who knows, probably this is not something bad, however I just mention it.

V in.

V out.

On the plus side, there was a significantly lower THD that was claimed at the output.


THD in.

THD out.

So, after performing a CleanWave demagnetization cycle, we started our listening again. We could not understand any sound difference toggling on and off the MultiWave function but since according to the manual this is something good, we left it on. We started with the Girl from Ipanema and we continued with Intercontinental - Joe Pass (Japan Pressing ULX-25-P, MPS / BASF). Wow, the results where very good: both tracks were sounding much more airy with a better sense of space and a bigger and focused soundstage. Unlike the Quintet, here the work of Mr. George Marino was shining without any signs of oldness. We let ourselves get absorbed by the melody, forgetting about the machines. However, as it usually happens with these kind of devices, there were some mixed emotions when we changed the program. Dire Straights and a not so perfect Garry Moore recording were sounding better and more pleasant without the regenerator.

To be honest, we might have called it a day but I still had mixed emotions. Especially regarding the regenerator, I wasn't sure what to conclude - I mean, I couldn't make up my mind if it made things over all better or worse.

That is why after a couple of days we repeated the test at my home, at a different system and under different circumstances.

In the meanwhile, we have also started testing the PS Audio Noise Harvester - more about it at this post - so I thought to give it a try and plug it at both the Quintet and the Premier. At my home, there is a dedicated socket for the 2ch Hi-Fi system and another one for all the AV / PC equipment. Generally, the Noise Harvester would not blink, meaning I have clean power. Even when I turn on the WiFi, the LAN switch, plug in the laptop and turn on the custom made EMU PSU, all connected at the AV / PC power strip, the Harvester doesn't blink. But if I turn on my trusty Panasonic Plasma TV or my Home Theater BenQ projector, the Harvester starts blinking. So, I assumed that if I connect the Quintet or the Premier, turn on the TV and plug in the Harvester at one of the Quintet's or Premier's outputs, the Harvester should not blink; after all, both devices promise to provide AC cleaning. Right? Wrong! The Harvester connected at my normal power strip with the TV turned on would blink approx. 5 times per 10 sec. Plugged in at the Quintet it will blink approx. 13 times per 10 sec., indicating that... it has more cleaning to do. Connected to the Premier, it will blink like a strobe light at the refrain of a 80's disco dance song.

The Noise Harvester blinking on the Quintet...

... and keeps blinking on the Power Plant Premier.

Skeptical about this, Panos suggested to also plug in my TV at the Quintet or the Premier. "Maybe the isolation zones will kill the AC noise created" he told me. Logical thought I said and so we plugged both the TV and the Harvester at both AC cleaning devices. Well, things did not improved, the Harvester kept insisting by blinking that my AC is dirty. Unfortunately, I have to assume that one of the devices here is not doing what it promises to do.
Update: We also plugged the Noise Harvester on a PS Audio P300 regenerator. This was the only device that the Noise Harvest did not blink. Let me just note that the P300 is a true regenerator, making it's output completely from scratch. You can read about the P300 review here.

Anyway, we wanted to proceed with some listening tests. At Pano's home we listened from an analogue source and with the power amp connected at the Quintet / Premier. This time we left the power amp(s) (2x Luxman M-03 bi-amping) and the pre-amp (tweaked Luxman C-03) connected at my Audio Agile power strip and we connected the digital High Res front end (that is the VAIO laptop PSU and the EMU 0404 USB DAC PSU) at the PS Audio devices. Who knows, maybe these devices are more comfortable without power amps connected on them and they offer greater benefit at the supposedly noisy digital sources.

We started our listening with an excellent recording, an .iso file coming from the SACD of the album Getz / Gilberto remastered by Mr. George Marino. For first time readers, I remind that we have chosen this particular digital file after comparing it with another six digital versions. We started by listening with the usual setup and then we connected the Quintet. Again, it felt the same way: the soundstage opened up but the sound became grainy. Also, we noticed a lack of low end energy; it was not only that we heard it, we also felt it in means of less anticipated vibrations. Now, some listeners get confused when their base is tightened; they anticipate the tightening as reduction, but I assure you that this was not the case here. Don't get me wrong, we did not listen to very high levels neither this song is one with a lot of base. But my system is wonderful at reproducing a low end that is very well controlled and can be felt with your body from very low listening levels, something that the Quintet made it disappear. Also, the clarinet became a little aggressive at some points.

With the Quintet still connected, we listened to some rock: Deep Purple - Never Before (Machine Head, HDtracks 24-96). Again, the sound stage appeared to be wonderful and the organs were sounding very discreet. However, after removing the Quintet we appreciated the song better: the low end energy became more satisfying and the organs felt more of a part of a band rather than discreet solos.

We listened once more time to the Girl from Ipanema with my usual setup and then we plugged in the Premier regenerator. This time, I thought to take some output measurements with my multimeter, so I found out that there is indeed a "right" polarity to plug in the connected equipment - and so we did. By the way, the voltage drop that we noticed at Pano's home was also present here, however it seems like that the regenerator indicates a couple of volts less (both V in and V out) compared with what I get from my 5 digit true RMS mutlimeter. As I said, this is not necessarily bad but I would expect 230V AC output from a regenerator. Another weird thing is the THD; I had less THD in but the improvement factor of THD out was not as big compared to what we got at Pano's house.

VAC in...

... and VAC out.

THD in...



... and THD out.

Listening to the Girl from Ipanema with the regenerator, provided again a wonderful soundstage but we noticed a low end decrease - not as big however like the Quintet. The clarinet was just a bit more aggressive. Overall, due to the better soundstage I liked the sound but Panos was skeptical. Going to the rock track however (Deep Purple - Never Before) cleared things up: the sound was too "polite", lacking the rock energy. It was like eating spicy food without feeling the heat. We unplugged the Premier and we listened again, confirming that this device is not suitable for rock at this system.

Some thoughts and a conclusion.

High End is supposed to be the evolution of good old Hi-Fi, but I am afraid that it has more to do with different and exclusive than better. This goes to the perception that exists for devices like these and not the devices themselves. You see, the most common perception is that these devises will make your gear sounding better, whereas the true is that they will make your gear sound different. Unfortunately, a professional reviewer can not state such a thing for various reasons and a hobbyist needs a lot of confidence to face up all the "experts" accusing him for deafness, or even worse, accusing him for having a system that is incapable to highlight the superiority that these devises generously offer or the delicate improvements they cause.

So, are such devises worthless? No, they are not. In some cases, this "different" might also mean "better". But the key here is "in some cases". I mean, they are not a panacea of sound improvement.

The first thing I will say as a general rule is do not add a device designed to solve a problem that you do not have. You got to have bad AC power and own equipment that were not designed to deal with it, in order for the benefit of such a device to be bigger than the loss. Of course, the question here is how you are supposed to know if you are entitled of the problem. The best way is to get such a device and listen to it without prejudice, it doesn't have to sound better or else you are a worthless piece of shi-fi. If you can't borrow one, I would suggest to try it if the sound of your system is dull, missing details and sense of space in the sound stage.

My second concern is about the active AC devices. They will definitely imply a footnote at the sound of your system and you have to understand if this footnote will be a benefit for your sound. Also, they might have limits. So, maybe the big power amps should better stay plugged directly to the good old wall socket - it is a good idea to start the listening test by connecting only your sources.

Last but not least, a rather philosophical question; if you own equipment that suffer from the AC and you need devices like these to make them sound better, wouldn't it be better to choose other equipment that are better designed in the first place, and pay the extra funds there?

But wait a minute, you said you tested the devices thrice! I hear some of you saying.

Yes I did. What happened is that I left the text above unchanged - this was what I wrote just before releasing my post, but then a new system became available for testing. A new, different system, minimal and smaller than mine and Pano's system: Accuphase DP-500 CD player (yes, the same unit we had at this older post regarding CD players), PS Audio PCA 2 pre amp, PS Audio Classic 250 power amp, EgglestonWorks Isabel speakers (with the legendary Dynaudio Esotar tweeter), at their own speaker stands. Everything connected with XLR cables, plus some impressive Synergistic Research Resolution Reference speaker cables with active shielding. You will have the chance to read more about this system at various future posts also.

The test went like this: we had also available two other power amps, PS Audio HCA-2 & PS Audio GCA-500-EX. We had as a reference the PS Audio Classic 250 power amp. Question was if the sound of HCA-2 / GCA-500-EX was closer to the reference sound of Classic 250 with the aim of Premier regenerator.

Our system used for this test, from top to bottom: PS Audio HCA-2 power amp, PS Audio PCA 2 pre amp, Accuphase DP-500 CD player, PS Audio Power Plant Premier AC regenerator, PS Audio Classic 250 power amp. At the right the EgglestonWorks Isabel speaker, standing on its own stand.

At this point, let me mention that the Classic 250 has built in his own regenerator for the input stage, designed and fine tuned exclusively for this model. So the Classic 250 does not need to be connected to a regenerator.

The result was that both the HCA-2 and the GCA-500-EX benefited from the Premier regenerator and came closer to the sound quality of the Classic 250.

For a start, even without the regenerator, none of them has the notorious sound of a class D amp - I never liked class D but these amps redefine class D. I still believe that generally, class AB amps sound better with a more airy and 3-D soundstage, but class D amps can deal with really long speaker cables and have virtually unlimited drive.

Even though the low end of Isablel is limited due to small size, it benefited when the HCA-2 & GCA-500-EX were connected to the Premier regenerator. It became more solid and better controlled.

But where Classic 250 really shines is at the soundstage. It is this soundstage that the Premier helped
the HCA-2 & GCA-500-EX come closer to.

However, this is not true for the CD player and the pre-amp, They sound better when not connected to the Premier regenerator. You see, the regenerator made their sound too much "in your face", like a magnification glass at a point that you don't need magnification.

An interesting realization about the Power Plant Premier came during another test we were doing concerning the effect of power cables in sound. A power cable that improved the sound of the HCA-2 power amp, when it was connected at the input of the Power Plant Premier did not make any difference. But when this same cable was connected on the output of the Power Plant Premier feeding the HCA-2 power amp with power, it did further improve the sound.

Let me note that this system is plugged to a different electric installation and the Power Plant Premier kept being paranoid regarding what it considers or claims as a VAC out improvement. Weird thing is that it doesn't keep the same style of paranoia, as you have seen each time does it's own things.

An overrated value of VAC...

..and a weird consideration regarding "improving" it.

At a different day and as you will read at the middle of this post regarding power supply cables, we also connected the Quintet, which in this system sounded just a little worse than a common power strip.

So, my final thoughts and conclusion stay more or less the same. Somehow, I feel a bizarre satisfaction that my system does not benefit (need) regeneration. 

Happy listening as always!

Chris

 

P.S. You can also have a look at a review and measurements of the PS Audio PowerPlant 12 at another site, here.