One thing I wonder about is whether feeding my DNA-500 balanced AC would somewhat quiet its moderate physical transformer hum. Of course, using an even bigger transformer to accomplish that task might result in even more hum in the room. But as I said, the 500 does unequivocally sound better plugged into the EP than straight into the wall, more clear and lively.
Also in the case of this amp, it so happens that it's a fully-balanced device in terms of the signal path, including the speaker output, whereas the majority of amps are +/ground rather than +/-. Steve McCormack apparently feels that differential drive of the speakers is required to get the level of fine control he's after. Based just on the sound of this amp he could be quite right, but that's not a controlled test so I have no way of knowing the validity of this. But if there's something to it, then it seems plausible the same thing might apply in some fashion to an amp functioning as a power generator feeding other gear. |
Zaikesman, I think with power amps, the most important issue is the AC energy transfer. Obviously a good 10AWG PC is a plus, as well as good available AC. With balanced power units, I think the essential feature is common mode noise rejection, especially important for preamps, phono, etc., but not quite such a necessity for power amps IMO anyway. Plus of course, the size of the required transformer would be pretty large as you already mentioned.
In my reading of various threads/posts, most folks always concluded their amps sounded best plugged right into the wall, but that was usually compared with they're using some kind of conditioner. The only device which seemed not to limit t5he dynamics of a power amp was the use of BIG isolation transformers, which many people like Albert Porter seem to favor.
I did an A-B plugging my Levinson 23.5 into the EP-15A vs. the wall, (both on a ded.ct.) and couldn't really tell a big difference, so went with the EP; but I wouldn't plug a power amp into anything else (other than the wall ;--)
Now I'm using a new McIntosh MC275 Mk IV (tubes! oh Boy) which doesn't draw that many watts. Maybe I'll feed it some balanced power and see what it does?
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Not sure that filters ever become "old technology" in the sense that we will ever be without them, but regardless, if the entire waveform is being regenerated, it seems to me PS is not depending on filters to make a dirty waveform cleaner. But will the tracking power supply actually sound better, or even as good? Supposedly the technology is new and proprietary, but as far as I know power amps with tracking power supplies of different sorts have never enjoyed much of a high end reputation (Krell's bias plateau scheme excepted). The approach, when it's been used at all, has usually been for attempts at providing increased peak power capability in what are essentially lightweight, low-cost mid-fi amps (such as the NAD 2200 I once owned), not increasing efficiency per se. I assume this is more sophisticated stuff though, and PS posts some customer testimonials to the effect that the Premier outperforms the older Power Plants sonically.
I'd think power amps would benefit from balanced power just as much as front end compenents, or nearly so. The real hitch in that theory might be getting them the balanced power at an acceptably low powerline impedance, and that's where an efficient balanced regenerator could have an advantage over a balanced isolation transformer in terms of weight and size. I thought EP offered a tranny that could run power amps, but taking another look at their site I see that's not the case, same as with my Power Wedge Ultra -- the transformers used are simply not big enough, and the outlets designated for power amps bypass them. Since I've never tried a bigger BPT or Equi=Tech unit myself, I still don't know the answer to this one. Upon what do you base your feeling about this? |
Zaikesman, I said pretty much what you did (about the new PS) on another thread. It has a lot of bells and whistles and features with fancy names, but only the variable power supply is really new. Still handles noise with filters and inductors -- old technology IMO. I think powere amps do benefit from the EP-15A but I do not think they benefit much from balanced power. I save that just for front end stuff.
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Well, scratch my speculation about the new Power Plant Premier using a switching output amp. When I ACTUALLY WENT TO THE PS AUDIO WEBSITE AND READ ABOUT IT (real tough, that!), it was made clear that what's different now is a new type of tracking power supply, but it's still a linear amp, said to be pretty much the same as before otherwise but with a claimed 85% efficiency instead of 50% (Exact Power claims 97% efficiency for the EP15A). PS maintains that class-D topology isn't compatible with a power regenerator (they do use ICE in power amps) because of ultrasonic noise.
The Power Plant Premier (they dub it P3) now also features the ability to switch over to unregulated wall power if capacity is briefly exceeded (such as when an attached power amp is turned on from cold), like the Exact Power. Strangely if you ask me, PS doesn't play up their product's ability to deliver balanced AC without having to resort to an outboard balanced isolation transformer-based device. But it does now feature five of what they call "Iso-Zones" -- what appears to be a combination of inductive and parallel filtering applied to each of the five outlet duplexes, said to provide inter-component isolation -- similar to (but presumably not quite as absolute an isolation as) what I presently get from the API Power Wedge Ultra iso-tranny unit following my EP (who also offer balanced iso-tranny units to follow the EP15A). But I'd need to add yet another transformer-based component to get balanced AC to my power amp. Seems PS have also added a remote control, turn-on sequencing, cable and tele connectivity, and reduced the Multi-Wave complement down to one choice, the most popular one. And incorporated the surge protection into a removable module that can be more easily replaced in the event of protective failure. |
I have not used exact power products but I did have a PS Aduio 500 unit for several months in my system. For me at low volume and soft piano playing the unit was audible and for that reason I switched out. I am now using a SOund Applications X-12, which is very much to my liking. Not sure how loud or what you listen to but soft piano heard at low volume can be covered by the fan of the PS 500. |
Zaikes, I echo everything you said (and vice versa ;--) including power amp sounding even better through the EP.
I also wanted to mention a good reason to have the regenrator and balanced power unit as separates: The regenerator can/should go near the amp(s), powered speakers(Logans in my case) and powered sub(s). A BP device is useful near the source equipment, which may (probably) not be near the speaker/amp end of things, and will probably not need to be the same (high) capacity as the regenerator device. In fact I run a 15 foot 10AWG umbilical from my EP-15A over to the balanced SP-15A near my front end stuff. The whole system is "as quiet as a chair!"
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I own an EP-15A and like what it does.
The rap on the older PS Audio regenerators was that they necessarily were somewhat inefficient due to their use of a traditional linear amplifier to regenerate the entire powerline. Though I don't know the details, and haven't myself heard either the old or new PS units, it would appear that they've changed over to switching amplification now instead.
This would make them more similar to the EP, but without the feedfoward comparator technique, i.e., they still regenerate the entire powerline. Since the switching-amp architecture allows this to be done efficiently, it seems there'd be less relative advantage in EP's method other than greater compatibility with power amps and TVs, while on the other hand the PS approach allows additional features like MultiWave (of which I don't personally know the benefits) and balanced output (which I do, courtesy of my API Power Wedge Ultra's balanced isolation tranformers for sources only, and wouldn't want to give up). I guess one other potential advantage of the EP technique remains that if momentary demand exceeds capacity, the unit simply switches over uninterrupted to unregulated wall power and then back again after demand subsides. However, in my time with the EP using fairly high-powered amps driving 3-way towers in a mid-sized room, this function has never been necessitated at any volume level I can comfortably play.
But I will say this for the EP: Defying some 'conventional wisdom', my present power amp (a McCormack DNA-500) sounds distinctly less impressive plugged straight into the wall than into the EP. So -- maybe an EP for the plasma and power amps, plus a PS (old or new) for the sources? |
Cytocyle -- point taken. The result however is the same as a unit that regenerates ALL the AC it provides, but with much less power loss (and heat). So I guess technically, it should be called a "power correction" device. For me, the charm is that it doesn't throw the baby out with the bathwater, which allows it to provide high capacity and high efficiency at the same time.
The other thing I like about the Exactpower concept is the fact that it "fixes" those parts of the power cycle it identifies as carrying noise and other artifacts, without the use of the sonics-robbing methods employed in conventional power "conditioners." I just think the use of an efficient Class D switching amp with a feedforward comparison circuit a brilliant solution. So far, I can't find any negatives.
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Nsgarch: Actually it's not a TRUE Regenerator, it only fills in the voltage gap.
From Exactpower: "The EP15A is neither a power conditioner, nor a power re-generator. It is somewhere in the middle."
http://www.exactpower.com/ep15a.html
CDm: if you use your PS audio on the SIN only setting and don't boost the voltage or use any of the other features of the Powerplant, then the exact power model will do that.... But if you use the extra features the PS Audio 500 only add a little more power capability and has a number of ultimate outlets for the devices it can't power so it will help those other components but not all. So the PS Audio might allow you to use one or two low voltage products on the regeneration but the rest just plug into Power Ports.. Get a PS Audio Director 3.5 if you need lots of current and no regeneration. A Ultimate Outlet will clean up your plasma even more.
I am not familiar with the new PS Audio products to know whether they support full regulation and MW Settings apply to the full power amount.
Now saying that I liked the dynamics that my PS Audio Powerplant provided and helped immensely. But Utimately I switched to another Balanced condition that is very rare and built here locally in Phoenix. Platinum Power PP-1 makes music fluid. It supports a full 20amps and everything can be run though it.. hense the 55lbs it weighs. No heat is generate since it is only a balanced conditioner and not a regerator.
http://www.platinumpower1.com/ |
PS Audio has been advertising new power regenerators that are supposedly much more efficient (less energy loss as heat). You should look into that.
I like the sound of Accuphase regenerators, which are pretty efficient, but they are quite expensive. |
The Exactpower EP-15A has three times the capacity of the P500 and is a TRUE regenerator. It makes virtually no heat because unlike all other similar units, it doesn't "throw away" the entire incoming power, but "fixes" only the part(s) that are irregular. I can't recommend it highly enough. Exactpower also makes a (separate) balanced power unit the SP-15A, but from the look of your system, I don't see that you would benefit much from that capability anyway.
You should read about it in detail on their website:
www.exactpower.com
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