exactpower ep 15A

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 ;--((
.

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).

looking for black last gen ep15A -- anyone selling? thx

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.

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!