Axiom Home Page Forums General Discussion Home Theater anyone have XPA-1 amps?

i was looking at the emotiva website, and the though of getting 3 of these crossed my mind one for L/R/C...... does anyone here have this amp?

anyone had much experience with this company and their electronics?

Thanks guys!

I had trouble with the XPA-2 nearly 2 years ago, the head of the company or product development (?) was nice, I believe his name was Lonnie, emailed me some suggestions but I never could make it work with the M80s, it kept going into protect mode. I thought the XPA-2 sounded great until it crapped out and there was no sound, which of course was very frustrating. The problem only happened with HT sources with wide dynamic range but would happen frequently with dynamic peaks even at nonreference volumes, I never could make it happen with music even at 105 db, or even higher. Lonnie swore at the time that two XPA-1s, which were just then coming out, would work just fine with the M80s. I decided to punt and went with the A1400-8, never looked back.

Others have had no problem with Emotiva stuff, a few like me succumbed to the Emo jinx, which was largely confined to the M80s.

My guess is that the XPA-1s would most likely work well (although it's funny, if memory serves Lonnie told me that they would drive a 2 ohm load and I thought the wattage at 2 ohm spec was listed on the Emo website, now I see they only give specs for the XPA-1 driving a 4 or 8 ohm load; that could be important because at the time Lonnie kept insisting that the m80s would dip below 4 ohms in certain situations and this would trigger the protect circuit in the XPA-2, even there was no evidence from the M80 frequency response curve on record to support this claim. Lonnie believed that the absence of a protect circuit was what made the XPA-2 so responsive to instantaneous peaks but sadly the poor XPA-2 was no match for the power hungry M80s!).

Emo does or did have a 30 day return policy if you don't mind paying for shipping, which would add up some with 3 XPA-1s. Don't overlook the form factor, though, those suckers are huge, back breakers, and I didn't find the XPA-2 pretty to look at in my HT/living room, but of course such aesthetics are a matter of taste.

Let us know if you try out that setup, it sounds like fun.

A few years ago I had the king of the hill MPS-1s, also worked with Lonnie over a period of 3 months, replacing the mono's, etc. The amp kept going into protect mode prematurely, far before the Denon 2805 (at the time) would even break a sweat. Can't comment on if they have resolved these issues, however, they said it was the fault of the m80's dropping to 1ohm, not.

next week i'll have a pair of m80's and the vp180 connected to my XPA-5 emo amp. there will also be a pair of Polk TSi200's at 8 ohms connected as surrouds to that same amp at the same time. i'll try my test with the surrounds on and with the surrounds off and see if i have any issues. i'll be sure to check back with this thread and let you know if i'm having any troubles. mind you i don't play my music or movies at ear blead levsls cause i can't stand it.

i'll let you know if i have any troubles at the volumes i listen to. don't know that it will make any difference one way or another but all 3 of my axioms will be the V3 models. i'll keep you posted. i will also test it out on some movies that have really powerful soundtracks too and i'll crank it a bit beyond what i usually listen to things at to see if anything happens.

That is interesting that a dedicated amp would not be able to handle a short period of a 1 ohm load... I would think the power supply would be big enough to support that for a short period anyhow? especially if a receiver can power the same speaker just fine.... And that can't be Just an M80 thing, any speaker with a normal impedance of 4ohms, is going to drop below it, depending on the frequency.......

In my case they said there was a special circuit on the MPS boards called a waveform limiter. This was what was turning the amps off, at one point they said if I removed this circuit from the amp boards they would not shut off anymore. I was suprised Emo was saying for a user to do this..

I don't know enough about ohms to say whether or not M80's dip to 2 or even 1 ohm during musical/theatrical playback. But one thing I have noticed is that most of the problems that we here on the board have heard about seem to come from the M80's, not from other speakers like the M60's. And from what I've seen on their forum and other forums is that they do fine with most other 4 ohm speakers as well.

So the question is, what else could it be? If they have protection circutry installed to shut it down in the event of a power spike (which would occur if a speakers impedance did dip down to 1 or 2 ohms), and that isn't that case with the M80's... then which characteristic of the M80's would trigger the shutdown?

the protection circuit could be set to be too sensitive. a short term protection should be set for a much higher value, than a longer term value...

axiom does not post the minimum resistance value or what frequency that occurs at, without this information one can only guess, without doing your own test to find the minimum value.....

I also have the MPS-1 driving M80's. I have not had the shut down issues that Randy did. I did have a buzz in one of my surround channels that Lonnie said was probably due to interference with a microwave tower - of which there is a large one within eyesight of my house. They gladly exchanged an amp module and I have been problem free since. Guess I'm one of the lucky ones.

Scott

I remember the thread about this amp being paired with the m80's a couple of years ago. Some folks were having problems and some weren't. Did any of the guys who were having problems exchange the amp or components for new ones to see if that resolved the issue? If it did resolve it then the amplifier design isn't the problem, it is more of a quality control issue. However, the customer service issue needs to be fixed and hopefully is by now. Rather than looking at a problem with the amp itself (maybe a faulty component?) they seemed to be blaming the difficult load of the m80's imposed on the amp and that was it. The entire point of having a separate amp is to be able to drive speakers, that may be difficult to drive, to reasonable levels (and even reference levels if desired). And some folks couldn't even do that with the Emotiva amp.

If I remember correctly Randy did exchange components on his MPS-1 a number of times before giving up. A year or two later when I spoke with Lonnie he wouldn't even bother with replacing or exchanging anything, he simply suggested that the XPA-2 and the M80s were a mismatch and offered the suggestion of two XPA-1s to drive the M80s (at twice the price).

Jiminy Xmas.

I keep looking at the UPA-2 longingly, but all these reports make me nervous. I'm also nervous about the heat generated by the thing, since it's an AB, not a class D. Someday, maybe, someone will make an affordable (read, ridiculously cheap) class D stereo amp not based on ICE. I'm looking at you, Ian.

emotiva has the same 30 day return policy as axiom so perhaps you'd like to give them a try. i own both a UPA-2 and a XPA-5 mind you they are currently driving 8 ohm loads but neither one of them gets hot, in fact after watchine avatar at a good volume (not ear bleed) the XPA-5 was only slightly warm. when i first got the UPA-2, i did a test and ran my fronts off of it for about an hour and it barley got warm.

again, this was with 8 ohm loads. when i get my new front 3 from axiom i'll see how the XPA-5 will handle the 4 ohm loads combo'ed with two 8 ohm loads for 5 speakers running on it. i'll be sure to let you know if i see a real noticable temperature rise or not. i should also state that both of my amps are completely out in the open with free air on all sides nothing stacked on them and they are not enclosed in any way. if that helps.

It does help! Thank you!

I know this is going to sound like I'm an absolute idiot when t comes to electricity (which isn't far from the truth), but I'm just thinking outloud (well, typing out loud... No wait I'm... Oh nevermind) so bare with me...

Since heat is one of the main limiting factors when it comes to amps, and thermal shut-down, I'm just curious if it would be at all possible to create a 'liquid cooled' amplifier? Of course I don't mean submerging the amp in water, but merely creating an enclosed casing around the heat sink with some sort of circulating liquid to cool it down. So long as the liquid didn't touch anything but the heat sink, wouldn't that be possible?

I can understand that its probably cost prohibitive to design such a system, and the danger of the liquid escaping into the electical part of the amp has undesirable side-effects to say the least. I'm just wondering if any really high-end/high capasity amplifiers have ever incorporated this kind of cooling technology into their design, or if its simply impossible to combine liquid cooling with an electrical amplifier?

Again, I'm just thinking (typing) out loud, so don't laugh too hard if the notion is perposterous.

Micah,

You're not out in left field at all. It's done with computers all the time. I don't see why it couldn't be applied to audio amps, or the like.

My MPS-1, even after a 3 hour movie, is cooler than the pre-pro feeding it. It's a Class H amp, whatever that is.

Scott

Drippy...

It could go back even further than that. But once I found that article I stopped looking. It's been done. Wonder why it's use has been so limited though, and why we don't see any liquid cooled HT amps around? It seems to me it would greatly reduce the size/weight of an amplifier if they didn't have to employ such massive heatsinks to dissipate all that heat, and would also make for closer stacking of components as there wouldn't be a need for all that space around the amp to let the air in to cool it.

But I suppose they have their reasons. If it were indeed more efficient, somebody would be doing it.

Still gotta cool the radiator--the heat MUST go somewhere.

micah, often times the heat-sinks are NOT the majority of the weight, usually the heat sinks are aluminum fins, and with aluminum being light and a good conductor of heat, this is an idea metal to use... the majority of the weight of an amp is the power transformer.. next time your at lowes or home depot, go to the electrical isle and look for a transformer (you will see what i mean then)

as far as liquid cooled, you have to think about the market here... most of the liquid cooled pc's that i see are gaming pc's for guys that want to tinker, ect... most HT people want to plug their stuff up and go...

if you can keep the transistors cool, yes you can push them much harder, its called thermal breakdown... when they get to hot... just like your computer, the more you cool it, the faster you can make the processor run.... similar idea.


Right now i have Krell amps, and they are class A amps. so they do get Quite hot. i personally would not want a class D amp powering my main speakers, i guess im old fashion... but my amps cap out at 500W per channel.... Sounds like i would probably be better off getting an older Krell that will produce the power im looking for.....



Thanks for you inputs guys, i appreciate it.

What kind of amps did you say you had, again?

Krell
kav-250a and a kav 250a/3


here is a review.
http://www.hometheatermag.com/poweramplifiers/9/

if i bridge 2 channels, they make 1000W at 8ohms, but i don't know if i can bridge them with a 4 ohm load.

No, what kind of amps are they?

You guys are mean.

FUNNY!!! But mean none the less.

In that case it sounds like it's best to steer clear of Emotiva. I can't remember anyone having problem with Outlaw's amps driving any speaker. They are in about the same price category and you don't have to worry about the amp not working a year or two down the line. Or if you have the $2000 or $3000 to get the Axiom amp which would be better than just about anything else around at almost any price.

I know of one instance where Outlaw was not sufficient--Dennis was trying to drive 5 M80s + 2 QS8s at >100dB for hours on end, and the Outlaw 5 channel amp he had kept biting the dust. He eventually replaced it with Parasound Halos.

That, I think, would definitely be a border case.

I have a XPA-5 driving 2xM80 + the new VP180 + 2xQS8 and an UPA-2 driving another pair of QS8 and I have no problems both amps.

I think I liked the sound more when my m80 where driven by the Behringer EP2500 but did not do any A-B testing.

You can have five of their monoblocks for almost the same cost as their 5 channel 200 watt per channel amp. As long as you didn't put all the amps on the same breaker, I bet he would be able to drive his m80's even in that situation. Though the five monoblocks would take up a bit more space in the rack.

I remember your posts about the Behringer EP2500 and how much you liked it. I believe you had M22's at the time. Why did you replace the EP2500?

i remember that, didn't he get multiple parasound halos like 3+?

He got 4, I believe. All stereo.

Where did he go, i tried to search for he old posts, but couldnt find them....


he always had the best posts, with his cats in every photo i wanted to find out what kind of cats they were again.....

Playing 5 M80's at 100 db's for hours on end all the time, I'd say they were deaf cats.

actually they were cool as shit.. i think they were bangle cats a high breed of the regular US cat and a Bangle cat from china or something?