exactpower ep 15A


I'm looking at the above mentioned unit available used in an audio boutique in my vicinity. I've read a lot of good comments on it here.

I went to look for more info on it directly on Exactpower's site and found out it wasn't in their actual product line anymore. Technical data not beeing my stronghold, I wander if their new units use the same technology as the EP 15A and if not, why ?

Thanks !
andr
I know its a bit off topic with respect to this thread being EP focused however I loved the EP15A when I had it in the system. I've recently been using a PurePower APS 2000 and have not heard the likes of it from any manufacturer of active or passive power conditioners. It is well worth checking out...the results are amazing!
Seeing this thread pop up again, I must provide a link to another thread I posted to recently for my latest thoughts on using the EP-15A with high-powered monoblocks.

Upshot: I now plug my Equi=Tech 2Q that feeds my monoblocks directly into the wall instead of into the Exact Power, purely for sonic reasons (as stated above, I never had any problems that went to reliability). It's a tradeoff -- I do miss some of what the EP provided with the amps, but overall I've decided that in my current setup it's better if it doesn't feed the amps, only the sources (still via the PW Ultra with its b.p.t.'s)

I think I would probably love it if there was a way to feed the monoblocks' input/driver circuitry from the EP and their output circuitry from the wall (both via an appropriate b.p.t. for balanced AC), but unfortunately that's just wishing.
Hi Nsgarch, thanks for the update (actually I haven't followed any other Exact Power threads lately, so sorry for making you reiterate stuff you've posted before).

Let me state for the record that, while you may be qualified to commment on an electrical engineer's capabilities or the vagaries of the powerline, I am not. But I will share my own experience using the EP-15A in relation to the issues you raise.

My EP-15A is I believe the first version sold, at least in terms of cosmetics (after it replaced the model that preceded it -- the EP-2000 or something like that?), but I don't recall at this point what substantive differences (if any) may have pertained between it and a later version. It's plugged into the common 15A house wiring and breaker-board via a 3-pronged outlet and cord, no upgraded or dedicated circuit or added earth grounding.

I have no idea whether or not my unit has the added thermistor you mention, but as I'm sure you know, it does by design momentarily switch over to straight wall power when the draw exceeds its capacity, as during power amp turn-on (or very occasionally during program peaks at the highest listening levels, to allow unimpeded dynamics). I would have thought that this feature might itself innoculate the unit against damage from excessive current draw. The high-powered amps I've used with the EP include tube monoblocks rated 225wpc and solid-state stereo and monoblock models rated from 400wpc to 500wpc, the latter types in bi-amp combination.

Other than during vacations, my EP is normally left continually on (except for when heavy weather threatens and I unplug the entire system), my amps usually not. As per Equi=Tech's recommendation, the 2Q is normally also left permanently on whenever the EP is powered-up, but in any case it doesn't seem to draw an inrush current at turn-on equal to what any of my power amps do, as it has only rarely (maybe 5% of the times I've turned it on) caused the EP to default to wall power, whereas the power amps virtually always do. (The Power Wedge Ultra doesn't have an On/Off switch, which sonically speaking I think is even better -- but there isn't a draw issue either there or with the source gear connected to it.)

Of the amps I mentioned, the tube monoblocks seemed to cause the biggest powerline sag at turn-on, and if not staggered would routinely trip the house circuit-breaker. Yet none of this has ever caused any problem for or with my EP, which has in fact been totally problem-free in the several years I've had it (knock on wood) through thousands of amplifer turn-on cycles, as well as many powerline interruptions sufficient to cause it to reset (easy to see in retrospect because I normally keep the digital display switched off and it defaults to On mode).

So for me at least, so far so good (my criteria being entirely sonic and not alleged lightning-strike protection) -- and I wouldn't bother with the extra expense did not the b.p.t.'s I'm using in conjunction make a worthwhile improvement over using the EP-15A alone (and vice versa).
Zaikesman, as you know if you've been reading the various Exactpower threads, I did finally get MAP to initiate a repair service for existing owners, although (and I totally understand) Bob was not in a position to do warranty work. The EP-15A's are excellent units, and if the EP-20A ever materializes, it will be, as Bob says, "absolutely bulletproof!", and after he explained its features, I assure you it will be -- including taking a direct lightening hit!! Bob is a very talented engineer, and I have enough engineering chops myself to say that with complete confidence ;--) I could never understand why Paul McGowan (PS Audio) didn't jump on Exactpower to secure the patent. It turns out Bob bought the company to keep a personal friend of his employed -- what a guy, huh?!

Now, RE: "hanging" other devices (such as balanced power transformers) off an EP-15A. I know in the original literature for both the EP-15-A and the SP-15A balanced power unit, Exactpower advocates using them together, and I was told as much by Brent Jackson on the phone long ago. And in theory, there is no reason why this shouldn't be OK. HOWEVER, there is a serious design oversight (as opposed to design "flaw") in the EP-15A's: the first models had NO in-rush current protection. The later models added a little thermistor, but it is still insufficient protection if a big amp(s) or a large capacity balanced power device with a huge toroidal transformer (like the SP, Equi=Tech, etc.) are plugged into the EP-15A. With modern three-phase 120VAC, it depends WHERE in the three-phase power cycle you randomly happen to turn on the EP-15A. There could be a.) no harm done, b.) a blown fuse on the EP, or c.) one or more chips in the EP could get fried (as the momentarily overloaded EP-15A desperately tries to take itself off-line! ;-(( Another similar/related problem comes up for customers who live in places where the utility power suddenly turns off, and then instantly back on again -- causing large in-rush current conditions before any protective circuitry can re-set and engage.

The bottom line is: neither Bob nor I would would recommend hanging anything off the EP-15A's. Nor would we recommend turning on an EP-15A with attached equipment (especially amps) in the "on" position themselves. Let the EP-15A come on and boot up first, then turn on the attached devices. Bob has designed a module for the 20A model that actually "remembers" WHERE in the three-phase AC cycle the unit was turned off (or lost its power) so that when power is re-applied, the internal circuits' last settings are automatically synched-up with the new incoming AC power to avoid damaging them -- pretty slick, huh?

If, except for "thunderstorm season", you're someone who likes to leave their system powered up 24/7 (normally an OK thing) BUT, you have a problem with constantly interrupted utility power (as I described above) I would STRONGLY recommend purchasing a large capacity (20A, 1800+ watt) external in-rush current protection device; they're around $400 and up, or about the cost of fixing your fried EP-15A (that's IF it can even be fixed ;--((
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I am also an EP-15A owner, and spoke with MAP a few months ago about my sentiments regarding the excellence of that product and my disappointment that the new company has abandoned it. However, although I can't recall a name, I'm sure I was only speaking with someone in customer service, not a company officer.

I do want to mention, in light of above comments, that it's perfectly fine to hang a balanced power transformer off the output of an EP-15A, and in fact that's what the old Exact Power company intended for their complementary SP-15A unit, which is generally similar in principle and execution to units from Equi=Tech and BPT.

The combination of voltage/waveform correction from the EP and further noise-reduction/balanced-AC from a b.p.t. connected in series is not something I'd want to be without. I believe balanced-AC does more than just reduce powerline noise, I think it allows connected components to actually function better in and of themselves, often significantly so.

I myself take the wall power for my entire high-powered, bi-amped system and route it first to the EP-15A, then to an Equi=Tech 2Q for the power amps only, and also to an API Power Wedge Ultra 116 for the preamp and all the sources. (The PW uses six invidual smaller b.p.t.'s with six individual outlets to provide balanced AC for low-power sources while isolating all sources from each other on the powerline. However I do not recommend using the PW's four power amp outlets, which aren't balanced, for that purpose, or any other if you can avoid it, other than possibly feeding some battery trickle-chargers which may not accept balanced AC.)

BTW, not to jump on any PS Audio bashing bandwagon, because I generally like and admire the company and use one of their products, but it's worth noting (and has gone nearly unremarked-upon) that while the original Power Plant models did provide balanced AC, the current PP Premier that replaced them does not. The company has been, perhaps unsurprisingly, totally silent about this change in philosophy, as have all the reviews I've seen of the P3 whether out of acquiesence or ignorance. But if you followed the debate that took place in the Letters pages of Stereophile several years ago between Paul McGowan of PSA and Equi=Tech's Martin Glasband, McGowan stipulated that in his opinion at the time, balanced-AC was the THE single most important factor in terms of sonic improvement among the original PP's functions.

Also, for anybody considering the Equi=Tech 2Q (at least as it applies to high-powered power amps), I have found that in order to obtain the most dynamic, widest-bandwidth sound, I recommend using only the unswitched GFCI outlet duplex for that purpose, and if you use none of the other switched outlets for anything else, then in addition turn off those unused outlets from the front-panel rocker switch.
I don't remember what MAP told me however I do think they will tell you over the phone or point you to a local dealer if one exists for you that will give you this info.
Does anyone know how much the Exact Power EP-WSC-15R is selling for? Is it an improved version of the Ultrapure I? Has anyone got a hold of one yet?
PB, I'll try and take a minute to look into the two balanced models you mentioned and post any pros/cons I might discover. If I forget, feel free to email me and remind me ;-)

As for your other quandries ;-) here's my approach:

1.) Put in those dedicated circuits - biggest bang for the buck in audio! Here are the finer points:
a.) Two separate 15A circuits near your sources; not for extra capacity but to keep analog and digital separate.
b.) One 20A near the amps/speakers in the center of the end wall OR (just as an alternative, but especially if you are running monoblock amps) two 15A circuits, one on ea side of the room.
c.) Believe it or not, Romex is better than twisted wires in a conduit because the latter creates inductance, and RFI is better taken care of at/by the equipment itself.
d.) If your receptacles will be more than 20' from your breaker panel, go up one wire size from code to make up for voltage drop over longer distances. I.E. 10AWG versus 12AWG.
e.) Make sure the breakers for all your ded. cts. are on the same side of the neutral buss in the breaker panel box to insure they are all in phase.
f.) Use Hubbell hospital grade receptacles (with the green dot) because they have clamping connectors for the wire, as opposed to screw terminals (NEVER use 'push-in' connectors!)

2.) Voltage fluctuations: Once you've installed your ded. cts. you need to check the wall voltage at different times of the day (and night/evening.) It should not vary more than 5% over all (117 - 123 VAC) If it's higher or lower by more than just a volt or two (115 - 125 VAC), more than just once in a great while, and just for a few seconds, then you'll need voltage regulation, especially if you have tube gear. There are many inexpensive ways to do this. The least expensive being a voltage regulator(s) (duh! ;-) of the proper capacity. But, if it's a serious problem (like it's just too high or too low too much of the time,) I would FIRST talk to your utility company - they might need to replace a pole transformer!

3.) Subs with digital, or ICE, or Class D amps, should go right into the dedicated circuits' wall outlets. They create more noise than they are affected by it, and you don't want them dumping digital hash and in-rush current surges into your carefully balanced or regenerated power, from which they won't benefit anyway. They CAN benefit from big 10AWG power cords however ;-)

4.) If lightening and/or huge power surges are a problem in your area, the ONLY intelligent practice is unplugging your entire system. Seriously! Lightening can jump right across open circuit breakers and still fry your system -- so unplugging is the ONLY way except for: big isolation transformers. They will electrically separate your stuff from the grid (lightening) smooth out power surges, and eliminate a lot of noise. If I still had a house of my own, I'd combine dedicated circuits with isolation transformers, and be done with it!

Neil
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Nsgarch - You confirmed, pretty much, the design I had in mind. Thank you. However, I had thought about putting a regenerator upstream of the balanced power unit (still deciding between a 2qr equitech or BPT 3.5 sg plus - largely because I do not know how to evaluate the differences between the two, or if I should bother trying). So, if that is not a good idea, what other solutions are there to deal with the voltage fluctuations? Also, I assume the RG 1200 is good way to go on the regenerator side, are there other options you would consider? Oh - one other thought, the subs have built in digital amps (1000W) - would they benefit more from balanced or regenerated power?

Since I will be wiring from new dedicted ciruits - any thoughts on Romex, other than 10gauge? I could go with a two wire (hot, neutral) and twisting it and running a separate star ground, and then there is the 3 wire croy'd stuff...
Cheers.
I'm tentatively getting together with Bob at the end of July, so I'll have a better idea what he's thinking then.

Poonbean, balanced power has application primarily with low power devices (not usually amplifiers, in other words) that handle small signals (like preamps, mic and phono preamps, video equipment, etc.) They work great with equipment that already has balanced circuit topology or dual-mono topology (like a lot of the BAT stuff for instance.) It provides quiet, noise-free power without filters and chokes (as in 'power conditioners') by dividing (balancing) two 60 volt power cycles of opposite polarity around a ground. This causes the noise to be the same on both of the cycles but of opposite polarity, and guess what happens when it comes together? The two "noises" self-destruct!

The thing to remember is that there are certain power utility uglies that balanced power can't fix. The worst is voltage fluctuations -- a particular problem for tube gear, trying to maintain bias in the power tubes and constant heater(filament) current. And digital RFI can still get into the power outlets, unless the receptacles have capacitors across them. So that's when you need regeneration.

To answer your questions:

1.) No, but I haven't really delved into their individual peculiarities. Equitech was the first to get BP UL certified for residential use.
2.) Not if some of the outlets are "digitally filtered" which they usually are.
3.) I have my system arranged that way, with a balanced power unit near the front end and a regenerator for the sub/stats/amp. You could just use two balanced power units, one at each position; each plugged into dedicated circuits, and forget the regenerator, but before doing that, check your power outlets at different times of the day/night to see if you're getting fairly constant 120VAC.
Tethering a balanced power unit off of a regenerator is not a good idea as it can cause in-rush current problems for the regenerator.
Nsgarch: I have been following along on these threads for awhile now and am getting a great education (thank you very much), and it is clearly focusing me onto a balanced power solution - at least for the front end. But, I do have a couple of questions:

1 - Are you aware of any significant differences/benefits to Equitech v BPT v Furman?

2 - Would powering both analogue (eg - pre) and digital (eg CD) devices into, say a 2QR be problematic from the perspective noise generated by the CD?

3 - My amps and subs are near the speakers while the front end equipment is about 10-15 feet away - would you use another balance power unit for these, too?

I have the ability to rewire the entire room with dedicated circuits, which is part of the plan. I had also planned on the EP15A until I just read that support for the unit is no longer...

Thanks.
Nsgarch: Thanks....I was surprised to hear the bit on balanced power and residential applications from MAP too as companies like BPT, Equitech and Furman all still make great units in this category. BTW, MAP referenced the NEC Article 647.3 on the subject when I talked to them via phone.

I have an EP15A for power regeneration for my front-end equipment and am quite impressed. I was sorry to hear that they discontinued the EP, SP and UltraPure I offerings...

Thanks for the advice...good luck with your conversation with Bob S. at MAP.
Zephyr, it's true one of the key parts suppliers for the Exactpower audio units went under. However, balanced power is still perfectly legal, and you need only check with Equi=Tech, the original supplier of pro balanced power units, and the first to get UL certification for domestic units.
http://www.equitech.com/
I'm sure Balanced Power Technologies' units are perfectly legal as well.
http://www.b-p-t.com/
In fact both companies are now working together to promote balanced power.

Anyway, MAP's new products under the Exactpower name are quite unremarkable, and if you want a conditioner/filter unit, there are many better ones to choose from -- just don't use them with amplifiers ;-) I'm primarily upset that MAP has apparently turned its back on some brilliant power regeneration technology, and I just wish they'd sell it to someone if they're too shortsighted to realize its potential.

Next time (whenever that is) I have a conversation with MAP's president/owner, Bob Schluter, I'll ask him why he bought the company in the first place -- if he wasn't intending to use it's one truly valuable asset?

When that patent goes public in 15 years or so, look for a whole slew of efficient domestic power regenerators -- and we'll REALLY need them by then! Or perhaps someone will develop an even better solution . One thing is for sure, stone age products like the PS Audio Power Plant Premier which use generic and very inefficient technology, are going to be replaced very quickly now.
EP did sell to MAP. The reason (I'm told by MAP) they discontinued the EP15A, SP15 and Ultra Pure units is two-fold in that the manufacturer of the boards (or other parts) they need is no longer in business together with the fact that (for the balanced power units) they have stopped making balanced power devices as they are now reportedly illegal for residential use according to MAP. MAP has come out with new products in some categories for audiophile & studio use for noise suppression & filtering. One of them that looks extremely capable (and the successor to the UltraPure I) is the EP-WSC-15R...
I think Dave is right, plus the guys in the old Exactpower plant in Chatsworth CA (MAP is in NJ) are about to be let go I fear. So unless you can fix them yourself, you're out of luck, at least for the time being.

I hope that if I can't get MAP to start making the consumer units again, that maybe they'd be willing to license or sell the patent to someone who will.
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I have the exact Power EP 15A and had a issue. I called and no service unless I wanted to pay $$$$$$$ for them to trouble shoot. I had my plant electrician check it out and it was a 5.00 part needed that he picked up from a electrical supply. I would not think twice on buying another. If you really look inside there is little that can go wrong that cannot be serviced locally to my knowledge.
Dave
Thanks Neil,

I had a look at their website at the provided address. They specifically say that they will not repair units which are out-of-warranty. That is quite a downer !

Where could we get service for a product that has such a unique technology ?

Good luck with your negociations !
Regards !

I love my EP and my SP but I'm afraid Exactpower as a consumer product may be dead. The company was sold last year to Middle Atlantic Products Inc. They will be marketing full building systems under the Exactpower name but NOT using the patented Exactpower technology, which was light years ahead of stuff like the PS Audio Power Plant Premier. Sad, very sad.

The new website for the consumer products is now http://www.exactpoweraudio.com

The original website, http://www.exactpower.com is now being used to present the commercial products.

But keep checking. I've been talking to the president of Middle Atlantic trying to convince him that promoting the consumer products is the key to success in the commercial/industrial sector. Wish me luck ;-)

In the meantime, I wouldn't discourage anyone from buying even a used EP-15A, as they're very efficient and quite reliable when "used as directed" ;-)

Neil
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