Emotiva XPA-2 Maximum Output Considerations . . . DON'T USE POWER CONDITIONING!!!!

SolidSqual

Early B. wrote: »

This may help a bit, but from what I understand, the specs are terribly understated. For instance, the XPA-2 is still listed on the Emo website as having 120,000 uf of capacitance, but when I popped the hood, there was 180,000 up in there.

I'm guessing the XPA-2 is capable of handling a 2-ohm load or even lower, but Lonnie doesn't recommended it. Here's the direct quote:

"The reason they [XPA-2 and XPA-5] are not rated or recommended for 2 ohm operation is due to power requrements. When you go from 8 ohms down to 4, the amount of power the amp draws from the wall doubles and when you go from 4 down to 2 that doubles again. If you were to run the amps at a continous 2 ohm load with dips dropping down to 1 ohm a 20 amp circuit would not be able to support the load and you would pop the break. Not to mention the heat generation would go up exponentially. The output of the amp itself would go quadruple, so forth and so on."

EarlyB: That explains so much. I did the same thing, but thought I was an idiot when my mulitiplication kept coming up with 180,000.

mmadden28

I'm reading a few misinterpretatons here....

F1nut wrote: »

That's interesting as they list the specs as following,

Power output: 250 watts RMS/ channel into 8 ohms, 500 watts RMS/ channel into 4 ohms and 1,000 watts RMS bridged.

So, in order to output 2000 watts it would have to be stable at 1 ohm, which I find highly unlikely. Maybe Lonnie could enlighten us on that, eh?

I think Lonnie misphrased his words and was actually referring to a power draw not output. Read the original post and look at the exact question that was posed--AC outlet power was the referenced question, not amp output power. He also in the same sentence mentioned the draw power including efficiency losses.

heiney9 wrote: »

I'd have to see 2800 watts to believe it. ****, the Pass Labs X1000 puts out 1000 wpc and the weighs 175 lbs and is all heat sink. Of course it idles at 600 wpc.
....H9

I doubt Lonnie is implying that you can or should ever expect to run your XPA-2 at levels that would draw 2000-2800 watts-only that it has or could be done. I would imagine he is closely involved with all the testing that the Emotiva products go through and like any engineer you need to know the limits of a product before you release it and its likely it may have been tested to levels that just might have drawn 2kw even if only for a transient spike. Granted these tests would be done in controlled lab environments with precision test equipment-not somebody's garage. You're car engine can run at higher RPMs than the engine was designed for, but that doesn't mean that you should do it (at least not often). Same goes for how fast the car can travel-you might be able to push it past 100, but you really shouldn't.

heiney9 wrote: »

...I'm sure the sustainable output of the Emotiva isn't much more than stock with the modded version as you'd need to quadruple the cooling area to achieve that output.

...also shorting the outputs has no effect is far more impressive than a "mod" that can achieve a theoretical 2800 wpc on paper.

.H9

H9, I think you misunderstood "mod"-I don't think SolidSqual meant "Emotiva Global Mod" to reference a 'modified XPA-2', but that Lonnie is a Global Moderator for the Emo forum (and Emo VP)

SolidSqual wrote: »

... The metal of the cover is kind of thin and does not portray the same aesthetic power as the amp conveys in sound. In addition, ventilation slots like that of a common Yamaha receiver are spread across the top of the cover in a grid pattern. I don't like that. It reminds me of cheaper electronics. I much prefer the Odyssey top covers as they are lke plate armor. But again, this is an extremely minor complaint and really the only oneI have now. ....

Personally I don't see any problem with the top cover-it does its job and IMHO is not really that thin.



One area of concern I do have though is; I can't remember exactly, but I am pretty sure my XPA-5 came with an 18awg power cord, but the amp is labeled to pull as much as 1800w (That's 15A). I replaced the power cord with thicker guage, but it still concerns me that such a small guage wire was provided. EARLYB or any other XPA-5 or XPA-2 owners-what guage power cord came with yours?
In one of my tests- with the XPA-5, the TV, and the DVD player on--I pulled max 11 amps with some some cranking loud volumes on Master and Commander (5.1) but averaged about 9. I'm sure the meter wasn't fast enough to show any spikes that may have pushed it higher to the limit though.

In a different post Lonnie mentioned running a 220v line to the amp. This way the current would be essentially halved. Has anybody tried to run like this (on any capable amp)?

Terrax

The XPA-5 I have shipped with an 18 awg. power cord as well, and yes that does seem rather weak. But what struck me most odd was the lack of a ground lug. Either on the supplied power cord or the amp itself.

mmadden28

Terrax wrote: »

The XPA-5 I have shipped with an 18 awg. power cord as well, and yes that does seem rather weak. But what struck me most odd was the lack of a ground lug. Either on the supplied power cord or the amp itself.

I noticed that on a lot of AV equip lately-Both subs I am trying out now have no ground. I guess that's one way to prevent a ground loop huh?

Terrax

Yeah, but only if every piece in the chain gets there.

Early B.

mmadden28 wrote: »

One area of concern I do have though is; I can't remember exactly, but I am pretty sure my XPA-5 came with an 18awg power cord, but the amp is labeled to pull as much as 1800w (That's 15A). I replaced the power cord with thicker guage, but it still concerns me that such a small guage wire was provided. EARLYB or any other XPA-5 or XPA-2 owners-what guage power cord came with yours?

I dunno. I NEVER use a stock power cord. I use 12-gauge or less on all equipment.

Thanks for the clarifications, BTW.

heiney9

SolidSqual wrote: »

I agree with every bit of your post. Simple designs coupled with creative topologies that use quality parts are what high end amps shouldbe. But, I didn't buy the amps because they touted extreme wattage nor was my point of this thread to tout such wattage. I bought the amps because I knew they would sound better than my S300s. I started this thread because I was concerned my amps would not be able to reach their full potential with my PPP in the component string.

Watts aside, Emotiva makes a damn fine amp. In fact, one thing that keeps bothering me is my own common sense. I feel like the amp has to be cheating me somehow. There's just no way something like this could cost so little. My only complaint is that the top cover is not very modern. The metal of the cover is kind of thin and does not portray the same aesthetic power as the amp conveys in sound. In addition, ventilation slots like that of a common Yamaha receiver are spread across the top of the cover in a grid pattern. I don't like that. It reminds me of cheaper electronics. I much prefer the Odyssey top covers as they are lke plate armor. But again, this is an extremely minor complaint and really the only oneI have now. It's sad, but I feel like I should be finding more things wrong for the little money I paid. But, I'm not. It's stupid. I'm stupid.

SS,

Don't take my post the wrong way. I've heard great things about Emotiva and I will try one one day. My post was intended to be a more general comment about amps in general (it was just posted in this thread). Enjoy the amp and believe me, I have been in your shoes about "this is too good to be true" syndrome.

H9

SolidSqual

heiney9 wrote: »

SS,

Don't take my post the wrong way. I've heard great things about Emotiva and I will try one one day. My post was intended to be a more general comment about amps in general (it was just posted in this thread). Enjoy the amp and believe me, I have been in your shoes about "this is too good to be true" syndrome.

H9

Hey,

Sorry if I came off crossed about your post. It wasn't the case at all. In fact, I really appreciated the comments as they led to some interesting conversation.

Thanks,

Mike

SolidSqual

Early B. wrote: »

I dunno. I NEVER use a stock power cord. I use 12-gauge or less on all equipment.

Thanks for the clarifications, BTW.

Me too. I didn't even look at the stock PC. I had my trusty Signal PC waiting before the amps arrived.

DarqueKnight

The response Mike received from Emotiva prompted me to ask the same question of Parasound.

This just in from Parasound technical support:

"Unless you are in an area that needs protection from lightning or brownouts, or unless you are experiencing problems with your power, we do not recommend the use of power conditioners for our power amplifiers. You would require a very expensive commercial grade power conditioner to meet the current demands of the JC 1."

SolidSqual

DarqueKnight wrote: »

The response Mike received from Emotiva prompted me to ask the same question of Parasound.

This just in from Parasound technical support:

"Unless you are in an area that needs protection from lightning or brownouts, or unless you are experiencing problems with your power, we do not recommend the use of power conditioners for our power amplifiers. You would require a very expensive commercial grade power conditioner to meet the current demands of the JC 1."

Jeez, can you imagine how many people use power conditioners to protect their equipment and improve sound when in actuality they are doing more harm than good? How many installers sell mega amps to people along with crummy power conditioners?

This thread has really altered a lot of what I learned when first becoming interested in high end audio a couple years ago.

Face

For those of you who liven in a area with a crumby electric service, this UPS can pass 1500 watts. http://catalog.belkin.com/IWCatProductPage.process?Product_Id=258472

iskandam

I quickly replaced the stock cable with Signal Magic power cord when I got unboxed the XPA-5. I'm upgrading to silver pc to see what kind of improvement I can get this time

MillerLiteScott

Where does current come to play in this? Is it related to the wattage output or the draw?

mmadden28

MillerLiteScott wrote: »

Where does current come to play in this? Is it related to the wattage output or the draw?

Draw

Systems

Plitron who are the suppliers of transformers to most of the hi end amplifier manufacturers (atleast in Canada and the US)have developed a line of power conditioners that will allow you to hook up an large amp without the fear of limiting the amount of current available.http://www.toruspower.com/rm_100_bal.htm Unfortunately it costs as much as a hi end amp and needs to be hooked up to both phases of the AC. (240 volts).

If one only wants surge protection then one of the 15 or 20 amp rated products from ZeroSurge should fit the bill.

Serendipity

Pardon my ignorance, but...

I just *don't* understand how an amp can draw so much under normal listening. I have my Onkyo connected to a UPS, and the load indicators never show more than 90W. That's with a PC, AVR, CDP, DVD, and some other stuff connected to it. I'm sure that PC is already 50% of the 90W on the UPS.

2800W? Unless the amp is at 100% and clipping, I don't believe in the real world you'll ever need to draw THAT much.

Systems

appadv wrote: »

I just *don't* understand how an amp can draw so much under normal listening.

If the speakers are somewhat low in sensitivity and present a rather low impedance load to the amp then its possible.With very dynamic source material there may be demand for this kind of power,but it will be for very brief durations for reproducing loud transients like the cannon shots of 1812 overature.Most program material will not need this sort of output.


Some may remember Carver doing the scissor test.He recorded the sound of scissors cutting and played it back in a system with his highest powered amp at the time (400 or500 watt Phase Linear I think)and the amp clipped trying to reproduce this transient.

mmadden28

appadv wrote: »

Pardon my ignorance, but...
...
I just *don't* understand how an amp can draw so much under normal listening. I have my Onkyo connected to a UPS, and the load indicators never show more than 90W. That's with a PC, AVR, CDP, DVD, and some other stuff connected to it. I'm sure that PC is already 50% of the 90W on the UPS.

My PC draws about 150watts idle. It has a quad core , a single decent video card and 2 hard drives. I believe my HT setup (which does not include the PC)drew 11 amps at its max (that I have been able to observe so far). I still have to do some definitive current usage measurements of each of my components.

appadv wrote: »

...2800W? Unless the amp is at 100% and clipping, I don't believe in the real world you'll ever need to draw THAT much.

You wouldn't in the real world. This figure would have come from either a theoretical calculation or from manufacturer testing the limits in a lab with specialized equipment. 2800 watts is not the rated current draw of this amp. However the extra capability allows for the headroom of transients and other very short bursts which would prevent clipping.

heiney9

MillerLiteScott wrote: »

Where does current come to play in this? Is it related to the wattage output or the draw?

Depends on the design. It's a push/pull A/B amp so I'm guessing it's a voltage driven amp vs. a current driven amp. High current and reserves are essential for a voltage driven amp. This is beyond the scope of this thread as now we are getting into the nitty gritty of amp design and component selection.

Serendipity

mmadden28 wrote: »

My PC draws about 150watts idle. It has a quad core , a single decent video card and 2 hard drives. I believe my HT setup (which does not include the PC)drew 11 amps at its max (that I have been able to observe so far). I still have to do some definitive current usage measurements of each of my components.

Wow, that's a nice PC setup you've got there! The reason my PC draws about 1/3 of that is because HP designed it with living room use in mind, so some of the components are not desktop based. Another dual core system I have in the house draws approx. 100-120 watts.

vonnie123

I live in Socal (EDISON POWER) and wouldn't be without a power conditioner, especially one that trims, and boosts voltage. I took a look at the Emotiva XPA-2 owners manual and didn't see anything about not using power conditioners. That probably should be added to their manual if it's a concern.

mmadden28

appadv wrote: »

Wow, that's a nice PC setup you've got there! The reason my PC draws about 1/3 of that is because HP designed it with living room use in mind, so some of the components are not desktop based. Another dual core system I have in the house draws approx. 100-120 watts.

If I built one for my HT, I don't think I would be using Quad core or the higher end video card (but still capable vid card mind you)--I would definately gear it for lower cooling requirements-thus quieter. This was for gaming, although I still built it with quiet computing in mind. I put an 800w power supply in it expecting to be pulling at least half of that-But I haven't overclocked, etc yet.

mmadden28

vonnie123 wrote: »

I live in Socal (EDISON POWER) and wouldn't be without a power conditioner, especially one that trims, and boosts voltage. I took a look at the Emotiva XPA-2 owners manual and didn't see anything about not using power conditioners. That probably should be added to their manual if it's a concern.

Actually there was mention of using one, but only if you experienced pops and clicks, however Lonnie has mentioned that that will be deleted from the next version of the manual (if not already). I agree though, it should be made VERY CLEAR about not using one if that is the preferred way to go.

Systems

MillerLiteScott wrote: »

Where does current come to play in this? Is it related to the wattage output or the draw?

Simply,for an amp to acieve its full output potential it needs to source a certain amount of current from the AC line.If it can't source the required amount then its power output will not reach maximum.

SolidSqual

Ok so I disconnected my PPP and plugged the amps into the wall. Guess what, it sounds good, but now I have an aggravating buzz. Obviously the power in my apartment is dirty as hell.

Can someone please give me a solution so that the noise is filtered without hampering the ability of the amp to draw the proper current.

Thanks

Mike

Systems

SolidSqual wrote: »

Can someone please give me a solution so that the noise is filtered without hampering the ability of the amp to draw the proper current.

Chances are its likely a ground loop causing the buzz not dirty AC.

SolidSqual

Cheater plug the?

SolidSqual

hmmmm I'm gonna go buy some

Systems

SolidSqual wrote: »

Cheater plug ?

Not recommended as a permanent solution(that ground pin is there for a good reason)but certainly try one to verify that it is indeed a grounding issue.