klinemj
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Post by klinemj on Oct 9, 2017 4:49:47 GMT -5
They did guys, they just didn’t stress it as much as you wanted. (psst...I know they did...that's why I posted that...)  Mark |
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Post by leonski on Oct 9, 2017 13:06:00 GMT -5
Good points. However somebody would also see that all they would need is an amp that draws 3.5 amps for 99% of their needs! Which could be....the mini-x. Or pretty much any cheap avr on the planet. And then Emotiva would be bankrupt. This is assuming that all amps sound the same - which I disagree with. Amps really DO differ in the ability to drive reactive loads. That, IMO is the source of much of what people perceive as differences in sound. Highly reactive speakers may even be 'more revealing' but not of the music, but rather an amps ability to make 'em work properly. I don't offhand know of any Really Difficult HT speakers. They are designed to be used with HT receivers, mainly, which don't have the most robust PS and will simply fall apart when asked to drive more difficult loads. Exceptions may exist. But not at 'popular price points'. Also, let's say you decided that since you have 99db sensitive speakers, that you really only need a good 100 watts or so. 5 watts per speaker with 100 watt peaks is Wacky Loud. That is a 13db crest factor. And unless you live very Rural, may piss off the neighbors if done too often. But since the housekeeping demands are much lower for this amp than a Mondo Amp, the efficiency at these lower powers is actually higher. You may have, not about 350 watts at idle, but 40. And to get to 8 watts total output, only need an additional 40 watts (I'm making the math easier by choice, here) so your efficiency is now 8/80s or 10% .. I have NO idea, which is ALSO what this thread is about. What that does that mytical amp really measures? So, to get the power you need, you might end up drawing far less than the 3.5amps of the High Power solution. |
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KeithL
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Post by KeithL on Oct 9, 2017 16:42:11 GMT -5
I don't disagree with a single thing that's been said in this thread... but... Most speakers are not 99 dB efficient; in fact, the average efficiency of most modern speakers is more like 90 dB. And, yeah, most super-high-efficiency speakers do sacrifice something in return for that efficiency. The reason for this is that there are always tradeoffs between efficiency, cost, and other factors affecting sound quality. Nobody deliberately decides to make a less efficient speaker unless they gain something in return. A lot of modern speaker designers have been overheard saying stuff like: "Now that amplifier power is so cheap, I don't have to worry so much about efficiency, which lets me put more effort into designing a better-sounding speaker". So, yes, if you already have very efficient speakers, or are willing to limit your choices to the short list of speakers that fit that description, then you can probably be happy with a low powered amp. However, if you want to be able to choose between the majority of modern speakers, and want to be able to drive them to relatively serious listening levels, then you really do need significant power. Obviously everyone has different needs and priorities.... I've known a few people who were happy with 35 watts/channel - or even 10 watts/channel.... However most people these days want just a bit more  Here's another interesting thought...... after all this discussion about amplifier efficiency....... How about SPEAKER EFFICIENCY? By the numbers, a speaker with a sensitivity of 92 dB (at 1W at 1 meter) is about 1% efficient. And a speaker with a pretty high sensitivity of 99 dB (at 1W at 1 meter) is about 5% efficient. Good points. However somebody would also see that all they would need is an amp that draws 3.5 amps for 99% of their needs! Which could be....the mini-x. Or pretty much any cheap avr on the planet. And then Emotiva would be bankrupt. This is assuming that all amps sound the same - which I disagree with. Amps really DO differ in the ability to drive reactive loads. That, IMO is the source of much of what people perceive as differences in sound. Highly reactive speakers may even be 'more revealing' but not of the music, but rather an amps ability to make 'em work properly. I don't offhand know of any Really Difficult HT speakers. They are designed to be used with HT receivers, mainly, which don't have the most robust PS and will simply fall apart when asked to drive more difficult loads. Exceptions may exist. But not at 'popular price points'. Also, let's say you decided that since you have 99db sensitive speakers, that you really only need a good 100 watts or so. 5 watts per speaker with 100 watt peaks is Wacky Loud. That is a 13db crest factor. And unless you live very Rural, may piss off the neighbors if done too often. But since the housekeeping demands are much lower for this amp than a Mondo Amp, the efficiency at these lower powers is actually higher. You may have, not about 350 watts at idle, but 40. And to get to 8 watts total output, only need an additional 40 watts (I'm making the math easier by choice, here) so your efficiency is now 8/80s or 10% .. I have NO idea, which is ALSO what this thread is about. What that does that mytical amp really measures? So, to get the power you need, you might end up drawing far less than the 3.5amps of the High Power solution. |
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klinemj
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Post by klinemj on Oct 9, 2017 17:01:19 GMT -5
Next up, I will present my "efficiency calculator"...where you can model the efficiency of each component in your system and determine an overall level. Prepare to be disappointed in what energy wasters we all are!
Mark
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Post by novisnick on Oct 9, 2017 17:20:10 GMT -5
Next up, I will present my "efficiency calculator"...where you can model the efficiency of each component in your system and determine an overall level. Prepare to be disappointed in what energy wasters we all are! Mark Thanks Mark, please include the energy usage Coefficient for my RPR-1’s or VTA - ST-120 tube amps. Heat used is Not a loss! 😋 heat required during our deep freeze here in Louisiana,,,,,,,,  |
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klinemj
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Post by klinemj on Oct 9, 2017 17:23:41 GMT -5
Next up, I will present my "efficiency calculator"...where you can model the efficiency of each component in your system and determine an overall level. Prepare to be disappointed in what energy wasters we all are! Mark Thanks Mark, please include the energy usage Coefficient for my RPR-1’s or VTA - ST-120 tube amps. Heat used is Not a loss! 😋 heat required during our deep freeze here in Louisiana,,,,,,,, View Attachment The universe is a zero sum game...mass, volume, and energy. Mark |
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Post by Gary Cook on Oct 9, 2017 18:17:11 GMT -5
I really don't know what's so hard about this, since distortion measurements are carried out st these points why can't we ask for the power draw data? A make believe example;
In the XPA-2 Gen3 specs it could state something like draws <2 watts in standby, 180 watts at 1 watt output, 210 watts at 60 watts output and 390 watts at 300 watts output.
That would at least tell prospective buyers whether their power circuit can handle an XPA-2 Gen3 together with the other gear that's on the same circuit. Or if they already have an XPA-2 Gen1 or Gen2 that it is worth updating to a Gen3 to take excess load off that circuit. Keeping in mind that they can measure their current power draws with an inexpensive meter. But they can't measure a Gen3 because they haven't bought it yet because they need some comfort in its power draw suitability for their circuit/s.
That's what I see power draw as being useful for, not for say, how efficient the speakers need to be.
Cheers
Gary
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Post by leonski on Oct 9, 2017 18:44:02 GMT -5
I don't disagree with a single thing that's been said in this thread... but... Most speakers are not 99 dB efficient; in fact, the average efficiency of most modern speakers is more like 90 dB. And, yeah, most super-high-efficiency speakers do sacrifice something in return for that efficiency. The reason for this is that there are always tradeoffs between efficiency, cost, and other factors affecting sound quality. Nobody deliberately decides to make a less efficient speaker unless they gain something in return. A lot of modern speaker designers have been overheard saying stuff like: "Now that amplifier power is so cheap, I don't have to worry so much about efficiency, which lets me put more effort into designing a better-sounding speaker". So, yes, if you already have very efficient speakers, or are willing to limit your choices to the short list of speakers that fit that description, then you can probably be happy with a low powered amp. However, if you want to be able to choose between the majority of modern speakers, and want to be able to drive them to relatively serious listening levels, then you really do need significant power. Obviously everyone has different needs and priorities.... I've known a few people who were happy with 35 watts/channel - or even 10 watts/channel.... However most people these days want just a bit more Here's another interesting thought...... after all this discussion about amplifier efficiency....... How about SPEAKER EFFICIENCY? By the numbers, a speaker with a sensitivity of 92 dB (at 1W at 1 meter) is about 1% efficient. And a speaker with a pretty high sensitivity of 99 dB (at 1W at 1 meter) is about 5% efficient. Amps really DO differ in the ability to drive reactive loads. That, IMO is the source of much of what people perceive as differences in sound. Highly reactive speakers may even be 'more revealing' but not of the music, but rather an amps ability to make 'em work properly. I don't offhand know of any Really Difficult HT speakers. They are designed to be used with HT receivers, mainly, which don't have the most robust PS and will simply fall apart when asked to drive more difficult loads. Exceptions may exist. But not at 'popular price points'. Also, let's say you decided that since you have 99db sensitive speakers, that you really only need a good 100 watts or so. 5 watts per speaker with 100 watt peaks is Wacky Loud. That is a 13db crest factor. And unless you live very Rural, may piss off the neighbors if done too often. But since the housekeeping demands are much lower for this amp than a Mondo Amp, the efficiency at these lower powers is actually higher. You may have, not about 350 watts at idle, but 40. And to get to 8 watts total output, only need an additional 40 watts (I'm making the math easier by choice, here) so your efficiency is now 8/80s or 10% .. I have NO idea, which is ALSO what this thread is about. What that does that mytical amp really measures? So, to get the power you need, you might end up drawing far less than the 3.5amps of the High Power solution. Efficiency VS Sensitivity are the 2 most mixed up words in HiFi. Used interchangeably, they are not the same thing at all. And from our FWIW department, IF you have speakers which are about 1% efficient, that means that 99% is HEAT. The vast majority of that heat will be expressed in stuff like Voice Coils getting toasty warm, but some energy is used to actually warm the speaker enclosure due to mechanical flexing and such. It would appear that 'old school' Big Box speakers are, by physics, much more efficient than small box speakers. And Keith is 100%. Amp designers are making amps at power levels which Tube Guys only dream. It is still true, IMO that if you ARE concerned with efficiency that you get speakers of higher sensitivity. If you have 'average' speakers, per Keith, of 90db, than try to find some at 93db or better. That will instantly cut your amp needs by 50%. All other things being equal. Not to forget that you can have 2 speakers which let's just say you like. Both are of average sensitivity, around 90db. One is a bad load, however, with huge impedance / phase swings and doesn't sound good with your beloved KT88 tube amp. The other? A fairly 'benign' load which makes good use of even 20 or 30 a speaker. |
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Post by Gary Cook on Oct 9, 2017 23:10:30 GMT -5
Maybe my acoustic maths is rusty but if my stereo 2.1 speakers are rated 91 db, then I add 3 db because there is of course 2 of them. Plus another 3 db for the sub woofer and say around 3 db for boundary acoustics as my speakers are across a corner with the sub woofer right in the corner. To me that's 91 + 3 + 3 + 3 = 100 db. So 30 watts of Class A from the XPA-1L's for the L&R and 400 watts of Class AB from the XPA-100 for the sub is way more power than I use for my comfortable listening levels.
But that's irrelevant in the premise of this thread, my sample question is the same, will I have sufficient power available to replace my XPA-100 sub amp with an XPA-1 Gen 1 or 2? Or would a Gen 3 draw sufficiently less power to make its substantially higher cost worthwhile? Will it save me from having to upgrade the power circuit from 15 amps to 20 amps. Hence makes more economic sense in total spend terms?
Cheers
Gary
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Post by leonski on Oct 10, 2017 1:25:44 GMT -5
I just disagree with Keith. IN GENERAL no relationship between 'quality' of sound and 'efficiency' is known. Sure, lots of tradeoffs in the design phase. Everything that goes into a speaker is on-the-table for a clean sheet design.
And even those choices change when the reality of 'price point' design comes into play. Speakers have changed a LOT over the years, too. In the past, with mono being 'it', a large ported enclosure and horn tweet / mid were the norm. Lots of
DIY guys built these. OOOPS! Now you need TWO so where 'ya gonna put 'em? When acoustic suspension happened, it paved the way for small box speakers of much lower sensitivity. Just in time, SS amps came along providing more power, but at a price.
They originally sounded bad to many listeners. 'Grainy' and 'Transistor Sound' are terms you may still hear. As research proceeded, amps began to be a more 'known' factor and more good ones than bad were produced. The Phase Linear (early Carver) was
the exception. It would self-oscillate and burst into flames. Bad 4 Bob!
I may see a way out of Gary's dilemma. TOTAL plug to room efficiency is (PS% x OUTPUT% x SPEAKER Efficiency%) Even IF your amp PS was 90%, Output @ 60% and Speaker @2%, you still only end up with just OVER 1% total input being turned into sound.
Room gain? HAH! Higher Efficiency Amp? HO! Juggle the numbers all you will. You'll still not get to even 2% until you get much more sensitive speakers AND go to a 'D' amp which might be 90% plug to speaker.
Gary's original system, the 1Ls and the XPA for the sub sounds fine. IMO, any added cost for new stuff of higher efficiency will have a payback time measured in Decades.
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Post by garbulky on Oct 10, 2017 4:45:40 GMT -5
We've seen a lot of discussion about power efficiencies and it looks like we are talking about two things.
1. Power on idle.
2. Power consumption at normal listening volumes and maximum outputs.
And the person mentioned where this is truly useful are:
People who are somehow off the grid and have limited electric capacity. And therefore absolutely do need to calculate at least one of these things.
So here I am asking if such a person exists on this forum? All this discussion and I want to know....who are these people that need to know?
And if there is some other type of person where this information is needed ....
is there such a person on this forum where this info is useful? Would they care to make themselves known and talk to us?
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Post by garbulky on Oct 10, 2017 9:57:36 GMT -5
Nobody? There's been 130 posts about this...
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Post by AudioHTIT on Oct 10, 2017 11:45:34 GMT -5
We've seen a lot of discussion about power efficiencies and it looks like we are talking about two things. 1. Power on idle. 2. Power consumption at normal listening volumes and maximum outputs. And the person mentioned where this is truly useful are: People who are somehow off the grid and have limited electric capacity. And therefore absolutely do need to calculate at least one of these things. So here I am asking if such a person exists on this forum? All this discussion and I want to know....who are these people that need to know? And if there is some other type of person where this information is needed .... is there such a person on this forum where this info is useful? Would they care to make themselves known and talk to us?
You have repeatedly shown little or no interest in power usage, if anyone starts a thread about leaving equipment on or off, you practically brag about never turning it off, claiming it sounds better (whether it does is irrelevant to this discussion). I wouldn’t expect you to appreciate this, and if you don’t understand after everything that’s been written then I don’t think you’re going to get it. I care what milage my car gets — after it meets my other needs — I care how much power my refrigerator/television/computer/processor/light bulbs/etc uses — after they meet my other requirements — why shouldn’t I want to know how much my power amp uses — after it meets my other requirements. It seems many want to frame the conversation around why it doesn’t matter to them, claiming you should just care what it sounds like, whether it has enough power, that the power use is minimal compared to other things; or the conversation migrates to what technology is most efficient or that we should just buy different speakers. Some even imply we’re not smart enough to understand the specs. To me there are several possible benefits to users: knowing the minimal constant draw of an individual piece of gear (and thereby the entire system), knowing the average or maximum power an individual piece might draw (power amps likely being the highest power draw for most systems), and knowing the efficiency of a power supply to judge claims made by manufacturers (Gary’s primary premise). Having this information doesn’t mean we are going to choose a piece of gear based on how much power it uses; though if two pieces of equipment sound good, meet your needs, and are about the same price — but one idles at 20% of the other and averages twice the efficiency — then that’s the one I want to buy. I don’t expect you to have the same values as me, that’s fine, but I want to reduce all of the resources I use, which for me are primarily gasoline, propane, well water, and power (which includes how it’s generated). I don’t claim to be a good green citizen and am surely far from it, but I’ll continue to try and get better, this is one small way. For me it’s not about affordability (though I don’t like to waste money), and my home has more power and circuits than I will ever use. I don’t plan on going off the grid, though I might want to be able to power my home on solar and batteries someday (and in summer I have to use AC to get rid of the excess heat). I don’t see wanting to know power consumption and efficiency any different than wanting to know power output, distortion, circuit topology, available inputs, binding posts, size, weight, or color. Not everything we want to know has anything to do with how an amp sounds, even if that is someone’s primary criteria. Hopefully I’ve given you one perspective on why this information is important to some, at least to me. I’ll add that I won’t buy another multichannel amp without knowing idle power and something about efficiency. If I have to write the manufacturer to get the information then fine (as long as they answer), but I’d rather read it on the spec sheet along with everything else (and many already do include some of this). Is that really too much to ask? |
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Post by bolle on Oct 10, 2017 12:38:09 GMT -5
My amps have been measured at 2x 8 ohm loads set to 43V effective and putting out 2 x 231 watts while pulling 512 watts from the plug. This translates to 90% efficiency. To me they did sound better than the Sherbourn 7-350. Black magic?  Where is the problem doing and publishing measurements regarding efficiency? Are the numbers so bad?  |
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Post by leonski on Oct 10, 2017 12:56:13 GMT -5
People will be surprised about 2 things.
Power usage from amp is less than they suspect.
Efficiency at such powers will be dismal. High powered amps should have lower efficiencies than relatively low powered amps, for the same low output.
The new G3 switcher changes that a little, but I'd have to see data which I still suspect will be dominated by the A/B output.
Above, Bolle? 90%? Not from any A/B amp. Barely within realm of possible for a 'D' amp.
Nothing at all with taking your own data. Patterns will emerge if enough people contribute.
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Post by AudioHTIT on Oct 10, 2017 13:37:25 GMT -5
The Idle Power table is below I thought about starting another thread just for measurements, but there has been much good discussion here so I didn’t. I will however edit this post to include all measurements submitted here, or found in manufacturers specs, to have them in one place. I encourage anyone interested to measure and post their amp’s idle power (other gear welcome too). A Kill-a-Watt meter is generally the easiest and least expensive way, but if you have other methods you could tell us how you did it. I’m not ignoring efficiency, we just don’t have an easy way to measure it. I decided to move the data to another thread for better visibility and to encourage submittions from more Loungers! Post your results in this thread: emotivalounge.proboards.com/post/911602/thread |
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Post by Gary Cook on Oct 10, 2017 15:13:58 GMT -5
We've seen a lot of discussion about power efficiencies and it looks like we are talking about two things. 1. Power on idle. 2. Power consumption at normal listening volumes and maximum outputs. And the person mentioned where this is truly useful are: People who are somehow off the grid and have limited electric capacity. And therefore absolutely do need to calculate at least one of these things. So here I am asking if such a person exists on this forum? All this discussion and I want to know....who are these people that need to know? And if there is some other type of person where this information is needed .... is there such a person on this forum where this info is useful? Would they care to make themselves known and talk to us? Sorry for replying so slowly but I was asleep, it was night time in my time zone. I'm not off the grid, but I'm most certainly interested to know (as I have mentioned in several posts) whether or not I can fit an XPA-1 Gen 1 or 2 power requirements into the circuit to replace the XPA-100? Or if I'd be better off waiting for an XPA-1 Gen 3 with its lower power draw potential? Cheers Gary |
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Post by audiosyndrome on Oct 10, 2017 15:58:14 GMT -5
Data? You want the data? Here is the idle power for the last 31 power amplifiers tested by HiFi News: Idle-Current.pdf (23.96 KB) Russ Edit- the file should be named idle power. |
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Post by leonski on Oct 11, 2017 1:24:12 GMT -5
WOW! Great stuff. And all over-the-place with most of the 'D' amps being lowest consumption. And presumably 'Switchers'.
At least one of the amps is low enough that I'd be tempted to call it a class 'B' amp. It would have very minimal bias current.
Within the next couple days, I'll add my Parasounds to the list. I was at a friends graduation today and was gone for most of the day.
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Post by garbulky on Oct 11, 2017 8:58:14 GMT -5
Here's that list for those that can't view the posters attachment
Manuf. / Model Power Idle Power
Musical Fidelity M8500S 2 x 500/ 8 ohms 150 watts
Modwright KWA 150SE 2 x 150/ 8 ohms 155 watts
T&A A3000HV 2 x 300/ 8 ohms 160 watts
Krell Duo 300 2 x 300/ 8 ohms 140 watts
Primare A60 2 x 250/ 8 ohms 26 watts - Class D
Aesthetix Atlas SE 2 x 200/ 8 ohms 180 watts
Technics SE-R1 2 x 150/8 ohms 66 watts - Class D
Benchmark AHB2 2 x 100/8 ohms 19 watts
NAD M22 2 x 250/8 ohms 31 watts - Class D
Primare A34.2 2 x 150/8 ohms 22 watts - Class D
Naim NAP S1 1 x 746 (1 HP)/8 ohms 103 watts
Arcam P49 2 x 200/8 ohms 61 watts 385 measured
Constellation Audo Inspiration 2 x 200/ 8 ohms 127 watts
Classe Sigma Amp 2 2 x 200/ 8 ohms 34 watts - Class D
Luxman M-700u 2 x 120/ 8 ohms 104 watts
Rotel RB-1590 2 x 350/8 ohms 61 watts
Naim NAP 250 DR 2 x 80/8 ohms 16 watts
Jeff Rowland 625 S2 2 x 325/8 ohms 85 watts
D’Agostino Master Power Class 2 x 300/8 ohms 111 watts
Naim NAP 500 DR 2 x 140/8 ohms 33 watts
Bryston 4B3 2 x 300/8 ohms 102 watts
Leema Acoustics Element 1 x 210/8 ohms 12 watts
PS Audio BHK Signature 300 1 x 300/8 ohms 145 watts
Audio Alchemy DPA-1M 1 x 325/8 ohms 18 watts - Class D
Mark Levinson No. 256 1 x 400/8 ohms 213 watts
D’Agostino Momentum M400 1 x 400/8 ohms 116 watts
Are VX-5 Twenty 2 x 175/8 ohms 123 watts
Luxman M-900u 2 x 150/8 ohms 190 watts
Bel Canto Black MPS1 1 x 300/8 ohms 34 watts - Class D
D’Agostino Progression Mono 1 x 500/8 ohms 86 watts
Mola-Mola Kaluga 1 x 400/8 ohms 24 watts - Class D
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