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Post by infernost on Oct 13, 2016 18:40:44 GMT -5
Hi All Ok, I'm leaning towards getting the XPA-7 Gen 3 (I was thinking about starting with 4 amps but am not too keen on shipping the amp back and forth to have it upgraded, I love how UPS handle fragile packages) but did find something disturbing on the Specs page (See Below) and would like some clarification. It seems when more amps are added to the housing the available wattage output decreases, my question is why? I suspect that the SMPS isn't powerful enough to run all 7 amp's at their rated capacity. This whole thing just doesn't make sense, I hope someone can clear this up for me.  |
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Post by garbulky on Oct 13, 2016 22:15:59 GMT -5
Hi All Ok, I'm leaning towards getting the XPA-7 Gen 3 (I was thinking about starting with 4 amps but am not too keen on shipping the amp back and forth to have it upgraded, I love how UPS handle fragile packages) but did find something disturbing on the Specs page (See Below) and would like some clarification. It seems when more amps are added to the housing the available wattage output decreases, my question is why? I suspect that the SMPS isn't powerful enough to run all 7 amp's at their rated capacity. This whole thing just doesn't make sense, I hope someone can clear this up for me. View AttachmentThere is one power supply - a 3200 watt switching power supply. I'm not thrilled that it's switching but it is what it is. The power ratings are all channels driven. So what that means is there is only so much to go around....so with all channels driven to full the more channels you add, the less power there is to go around. HOWEVER....if you have 7 channels and you are only running two with music then you can expect the 300 watt RMS power rating to be output. If all seven channels are being run at the same time at full capacity - which is very rare for surround speakers to demand much power, then worst case every channel will get 200 watts of power. But in real life usage other than the front three, most channels will demand very little. |
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Post by AudioHTIT on Oct 13, 2016 23:49:30 GMT -5
Hi All Ok, I'm leaning towards getting the XPA-7 Gen 3 (I was thinking about starting with 4 amps but am not too keen on shipping the amp back and forth to have it upgraded, I love how UPS handle fragile packages) but did find something disturbing on the Specs page (See Below) and would like some clarification. It seems when more amps are added to the housing the available wattage output decreases, my question is why? I suspect that the SMPS isn't powerful enough to run all 7 amp's at their rated capacity. This whole thing just doesn't make sense, I hope someone can clear this up for me. View AttachmentThe XPA-7, which used a linear power supply and still "only" produced 200 W x 7, to produce more they'd have to go to a 20 Amp circuit, It's normal for any power supply to do what it's doing, I wouldn't worry about it. |
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Post by infernost on Oct 14, 2016 12:36:37 GMT -5
Hi All Ok, I'm leaning towards getting the XPA-7 Gen 3 (I was thinking about starting with 4 amps but am not too keen on shipping the amp back and forth to have it upgraded, I love how UPS handle fragile packages) but did find something disturbing on the Specs page (See Below) and would like some clarification. It seems when more amps are added to the housing the available wattage output decreases, my question is why? I suspect that the SMPS isn't powerful enough to run all 7 amp's at their rated capacity. This whole thing just doesn't make sense, I hope someone can clear this up for me. View AttachmentThere is one power supply - a 3200 watt switching power supply. I'm not thrilled that it's switching but it is what it is. The power ratings are all channels driven. So what that means is there is only so much to go around....so with all channels driven to full the more channels you add, the less power there is to go around. HOWEVER....if you have 7 channels and you are only running two with music then you can expect the 300 watt RMS power rating to be output. If all seven channels are being run at the same time at full capacity - which is very rare for surround speakers to demand much power, then worst case every channel will get 200 watts of power. But in real life usage other than the front three, most channels will demand very little. Thanks for the explanation but I understand what the specs are telling me, my confusion is if the main power supply was sized properly shouldn't you be able to get 300 WPC regardless of how many amps are installed in the chassis? Just saying. |
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Post by garbulky on Oct 14, 2016 12:42:34 GMT -5
There is one power supply - a 3200 watt switching power supply. I'm not thrilled that it's switching but it is what it is. The power ratings are all channels driven. So what that means is there is only so much to go around....so with all channels driven to full the more channels you add, the less power there is to go around. HOWEVER....if you have 7 channels and you are only running two with music then you can expect the 300 watt RMS power rating to be output. If all seven channels are being run at the same time at full capacity - which is very rare for surround speakers to demand much power, then worst case every channel will get 200 watts of power. But in real life usage other than the front three, most channels will demand very little. Thanks for the explanation but I understand what the specs are telling me, my confusion is if the main power supply was sized properly shouldn't you be able to get 300 WPC regardless of how many amps are installed in the chassis? Just saying. If the power supply had more capability then yes you would indeed get 300 wpc. You'd also be paying more for it.  Because you would be buying an amp capable of putting out 2100 watts of power @ 8 ohms. Which for example would be something along the lines of 4 XPA-1 gen 2 amps. The reality is there is nothing inadequate at the power output figures of a 3.2 kilowatt power supply. Check some other multichannel amps and see how many have a 3.2 kilowatt power supply  (Not many - and those that do cost over 10 grand). Though I will say I would much rather have a beefy torroid. Which I know will shock everybody here  |
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Post by infernost on Oct 14, 2016 12:50:35 GMT -5
Hi All Ok, I'm leaning towards getting the XPA-7 Gen 3 (I was thinking about starting with 4 amps but am not too keen on shipping the amp back and forth to have it upgraded, I love how UPS handle fragile packages) but did find something disturbing on the Specs page (See Below) and would like some clarification. It seems when more amps are added to the housing the available wattage output decreases, my question is why? I suspect that the SMPS isn't powerful enough to run all 7 amp's at their rated capacity. This whole thing just doesn't make sense, I hope someone can clear this up for me. View AttachmentThe XPA-7, which used a linear power supply and still "only" produced 200 W x 7, to produce more they'd have to go to a 20 Amp circuit, It's normal for any power supply to do what it's doing, I wouldn't worry about it. it sure would be nice to have 300 WPC on tap but is totally not necessary. My theory is if you have an amplifier module that can produce 300 and a chassis that can hold 7 amp's wouldn't you design a power supply that could support the load? You are right though, 200WPC is plenty for my needs and as garbulky said even with all channels driven not all will be outputting 200wpc. |
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Post by geebo on Oct 14, 2016 12:50:46 GMT -5
There is one power supply - a 3200 watt switching power supply. I'm not thrilled that it's switching but it is what it is. The power ratings are all channels driven. So what that means is there is only so much to go around....so with all channels driven to full the more channels you add, the less power there is to go around. HOWEVER....if you have 7 channels and you are only running two with music then you can expect the 300 watt RMS power rating to be output. If all seven channels are being run at the same time at full capacity - which is very rare for surround speakers to demand much power, then worst case every channel will get 200 watts of power. But in real life usage other than the front three, most channels will demand very little. Thanks for the explanation but I understand what the specs are telling me, my confusion is if the main power supply was sized properly shouldn't you be able to get 300 WPC regardless of how many amps are installed in the chassis? Just saying. If it could do 300 wpc with 7 channels driven it would likely be capable of 400wpc or more with one channel driven. Then we'd be asking why it can't do 400 wpc with seven driven. |
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Post by AudioHTIT on Oct 14, 2016 18:04:10 GMT -5
The XPA-7, which used a linear power supply and still "only" produced 200 W x 7, to produce more they'd have to go to a 20 Amp circuit, It's normal for any power supply to do what it's doing, I wouldn't worry about it. it sure would be nice to have 300 WPC on tap but is totally not necessary. My theory is if you have an amplifier module that can produce 300 and a chassis that can hold 7 amp's wouldn't you design a power supply that could support the load? You are right though, 200WPC is plenty for my needs and as garbulky said even with all channels driven not all will be outputting 200wpc. Again, they'd have to go to a 20A circuit to get that much power. The most powerful 7 channel amp they've made (that I'm aware of) is the Sherbourn PA 7-350, it did 350 W x 7 and had a very good reputation. However, it required a 20A circuit and many people can't provide that, it tends to make the amp less popular so I assume they chose not to do that with the XPA Gen 3. The reality is that in the 7 channel configuration the power supply is delivering more power than with any other, even though the individual channels are delivering less. Basically the line runs out of power. Here's part of a spreadsheet I did when the G3 first came out.  |
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Post by Gary Cook on Oct 14, 2016 21:39:48 GMT -5
The power supply is spec'd to use the most watts that the average US 110 volt power outlet can supply. Which is a bit of a shame as we have 240 volts in Australia.
Cheers
Gary
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Post by leonski on Oct 17, 2016 17:27:35 GMT -5
Gary, in the USA we have 15 amp cirsuits which would be 1.8kw and less continuous. Also is a 20amp which woulld be 2.4kw and less continuous.
What is the amp capacity of typical 220 circuits in Australia? What is the 'code' wire size needed?
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pcga
Minor Hero
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Post by pcga on Nov 27, 2016 16:53:19 GMT -5
The power supply is spec'd to use the most watts that the average US 110 volt power outlet can supply. Which is a bit of a shame as we have 240 volts in Australia. Cheers Gary What is the implication of that staement, Gary? We have 230 Volt in Denmark - 10A circuits. Does that reduce the power output from the the XPA Gen 3? Not an electric engineer, as you can hear! |
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pcga
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Post by pcga on Nov 27, 2016 16:54:49 GMT -5
The power supply is spec'd to use the most watts that the average US 110 volt power outlet can supply. Which is a bit of a shame as we have 240 volts in Australia. Cheers Gary What is the implication of that staement, Gary? We have 230 Volt in Denmark - 10A circuits. Does that reduce the power output from the the XPA Gen 3? Not an electric engineer, as you can hear! Maybe you know leonski ? |
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Post by leonski on Nov 27, 2016 17:15:08 GMT -5
I've seen the EMO staff chime in and say it was OK to run the XPR-1 on a 15amp circuit. I think spec calls for a 20 amp circuit. At least in USA @120vac or so. As it turns out? NOBODY really stresses their amp. Not to the extent of using THAT kind of CONTINUOUS power. The Bench Test Guys will use a VARIAC to keep the line voltage from sagging and affecting the measurments. Here is a small example. Only 500va so not for big amp testing. www.frys.com/product/4638758?source=google&gclid=CMT86bv6ydACFYqBfgodePgOwQThe PS caps ONLY recharge when the supplied voltage is GREATER than the voltage stored IN THE CAPS. Can't push it 'up hill', as it were. So under normal conditions? Even a Mondo-Amp doesnt' draw much juice. www.audioholics.com/amplifier-reviews/emotiva-xpr1-amplifierOn the BENCH if you want max, you needed that kind of current. In your house w/90db sensitive speakers? NEVER. That's why, IMO, it is nutty to buy a Mega-Amp without upgrading your HOME'S power supply to give 'em what they need. LOTS of clean current. And why I'm ALSO not a fan of running power amps thru a power conditioner. Newer generations of EMO amps have given up on the 20 amp requirement and are OK on 'normal' outlets, even multiple power amps. The 'all channels' driven power is strictly limited by what is available from the wall. I wouldn't get TOO wrapped around the axle about this. It will NEVER happen in real life unless you are listening to test tones. The only way you'd come close is to try to recreate an atomic bomb blast at 'realistic' levels. And than you're blowing speakers. GEEBO / GARY and others are correct. |
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Post by qdtjni on Nov 27, 2016 17:40:28 GMT -5
The power supply is spec'd to use the most watts that the average US 110 volt power outlet can supply. Which is a bit of a shame as we have 240 volts in Australia. Cheers Gary What is the implication of that staement, Gary? We have 230 Volt in Denmark - 10A circuits. Does that reduce the power output from the the XPA Gen 3? Not an electric engineer, as you can hear! The implication is that with higher voltage, it can provide more wattage using the same Ampere for the circuit.. So 10A with 230V is similar to 20 with 115V, that is usually good thing. |
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Post by Jim on Nov 27, 2016 19:03:35 GMT -5
I believe the 20A inlet on some XPR amps was a certification requirement based on the transformer VA (PS) rather than any real world scenario.
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Post by novisnick on Nov 27, 2016 19:04:13 GMT -5
I believe the 20A inlet on some XPR amps was a certification requirement based on the transformer VA (PS) rather than any real world scenario. True! 😀 |
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Post by dwaleke on Nov 27, 2016 19:53:52 GMT -5
I don't think people realize how little power they actually use.
A lot of people think they need "300 watts" for their speakers to sound good at 75db (for 99% of speakers out there that's using less than 1 watt) because they are rated for 300watts before they burn up.
I actually really like the way Emotiva has spec'd and is rating the Gen 3 amps. If you have a channel (or two) that needs a lot of power when the other do not then they get it. Genius idea.
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Deleted
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Post by Deleted on Nov 27, 2016 20:08:52 GMT -5
I don't think people realize how little power they actually use. A lot of people think they need "300 watts" for their speakers to sound good at 75db (for 99% of speakers out there that's using less than 1 watt) because they are rated for 300watts before they burn up. I actually really like the way Emotiva has spec'd and is rating the Gen 3 amps. If you have a channel (or two) that needs a lot of power when the other do not then they get it. Genius idea. Huh? I need close to 300 watts or more when I'm driving my front speakers, especially with BR movies up to 105dB's. This might only be a small percentage of the time but when I do need it then it's essential for clean sound. If I never played my speakers louder than 75dB, yes I wouldn't need the 300 watts. I know of no folks who never exceed 75dB's, what's your point? I'm rather confused. On the other hand, I don't think you realize how much power people actually use during high dynamic instantaneous peaks. |
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Post by Jim on Nov 27, 2016 20:13:10 GMT -5
I don't think people realize how little power they actually use. A lot of people think they need "300 watts" for their speakers to sound good at 75db (for 99% of speakers out there that's using less than 1 watt) because they are rated for 300watts before they burn up. I actually really like the way Emotiva has spec'd and is rating the Gen 3 amps. If you have a channel (or two) that needs a lot of power when the other do not then they get it. Genius idea. Huh? I need close to 300 watts or more when I'm driving my front speakers, especially with BR movies up to 105dB's. This might only be a small percentage of the time but when I do need it then it's essential for clean sound. If I never played my speakers louder than 75dB, yes I wouldn't need the 300 watts. I know of no folks who never exceed 75dB's, what's your point? I'm rather confused. On the other hand, I don't think you realize how much power people actually use during high dynamic instantaneous peaks. I've spent more than a few minutes playing with SPL calculators. For home theater, to get 110db or more at 10+ feet - it takes quite a few watts. Average listening isn't many watts. Dynamic peaks can use boat loads of power. |
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Post by Deleted on Nov 27, 2016 20:19:25 GMT -5
Dynamic peaks can use boat loads of power.
A big plus one!
(With very high power handling speakers at very high levels we can be easily talking 500-1000 watts.)
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Because you would be buying an amp capable of putting out 2100 watts of power @ 8 ohms. Which for example would be something along the lines of 4 XPA-1 gen 2 amps. The reality is there is nothing inadequate at the power output figures of a 3.2 kilowatt power supply. Check some other multichannel amps and see how many have a 3.2 kilowatt power supply 
(Not many - and those that do cost over 10 grand). 
