Talk:Amplifier figures of merit

Untitled

Amplification is a basic process sometimes seen in nature, and often used in processes which involve a signal which must be made stronger.

Removed. According to basic process, saying that amplification is a basic process is to say it is "a phenomenon which is one of the elemental building blocks of reality". I don't believe there is any significant body of human thought that makes this claim. Furthermore, it seems to border on meaninglessness, unless someone cares to flesh this claim out. For example, is amplification more or less "elemental" than, say, light, or souls, or cultures, or "the market", or fundamental particles? Whether you take amplification to be "fundamental" seems to depend entirely on the question one is asking, or the area one is investigating. Why do we need to claim amplification is elemental in general? --Ryguasu 08:35 Nov 12, 2002 (UTC)

An amplifier is a device which changes a small movement into a larger movement. But this also defines transformers as well as SImple Machines, and these are not amplifiers. An amplifier amplifies, i.e. there is energy-gain.--Wjbeaty 05:43, Mar 31, 2005 (UTC)

Though you always should mention where the extra energy is coming from, or risk both confusing newcomers and inspiring crackpots. - Omegatron July 9, 2005 19:18 (UTC)

who invented the amplifier

Perhaps Thomas Edison? The Carbon microphone is an amplifier. Edison even built amplifiers for long distance phone lines by connecting a loudspeaker to a carbon microphone and battery. But I don't know if there were earlier amps before this. See: [1] --Wjbeaty 05:43, Mar 31, 2005 (UTC)

Microphones are really transducers, which convert energy in one form (mechanical air pressure) into another form (electrical signals).

Generally they are, but the carbon mic is different in that it does amplify. Tabby (talk) 11:16, 7 June 2010 (UTC)

Complete Rewrite

This page is not really satisfactory as it is with lots of imprecision, errors and just lack of theme. I propose to rewrite.

Any suggestios/comments? Al212.74.96.201 03:58, 1 August 2005 (UTC)

I looked at this article again. I think the basic concept of an amplifier has to be layed out first. And lets not throw these big words around like "transfer function." I never met a tekky that could explain anything. I think when you know something you forget that other people don't know it. Let's go a little slower. Maybe we should be starting out with the idea that an electronic amplifier works by controling a large source of electrical power with a small one. To make this useful to people who know little about electricity, we can use the hydrolic analogy. The voltage is the pressure and the current is the amount of fluid that flows along. The British even call their vacuume tubes "valves". Then we could define power as having both current and voltage. Indeed voltage times current equals power, in watts. I'm surprised that no electrical people have looked at this. This article could turn out very nicely if given some help. Hey the guy down on "class of amp" has it right. Just go to electronic amplifier.69.122.62.231 (talk) 17:59, 15 February 2008 (UTC)

Lots of articles, not just this one, that have to do with electrical concepts are full of half truths, sometimes non-truths.

I think it is because they are written by enthusiasts, but not by actual specialists who have studied these topics and have contributed to the discipline.

You've said that on a few pages, but haven't given any examples. — Omegatron 19:35, 5 November 2006 (UTC)

I agree. This page suffers from a distinct lack of organization and an occasional lack of knowledge on the subject matter. I think the first sentence of the article sums up my point. I vote for a complete rewrite. Snottywong 16:55, 28 April 2007 (UTC)

transistor amplifier

Should we create an article for the different types of transistor amplifiers? We already have common base, common collector, differential amplifier, long-tailed pair, cascode and so on. Would be helpful to tie them all together. — Omegatron 18:07, 24 October 2005 (UTC)

I was thinking a nav box type thing would be handy. Three columns: FET, BJT, tube; three 'common-'s per column; and topologies along the bottom. Such a box could become bloated, though. - mako 07:27, 25 October 2005 (UTC)

Oh. I made it the other day. See Common_base#See_also. — Omegatron 12:27, 26 September 2006 (UTC)

External Links are Bad

This page explains about basic amplifier, but unneccesarily links to some 60w amplifier circuits. External links are not required for this page.

Class of amp

While it may not be written clearly it looks OK in terms of electronics design. I would suggest that as a external definative reference you use the first few chapters of the radio communication handbook published by the RSGB. This book is aimed at the radio electronics community but the ideas apply to audio equipment. I think that this page should be rewritten as an audio amp page, as it concentrates on audio equipment very much with the exclusion of things such as radio amps.

You may wish to read the page at Electronic amplifier which I suspect has been created and worked on by a different group of people who have not had much to do with this page.

Cadmium 16:41, 28 December 2005 (UTC)

Merge with electronic amplifier

This entry should be merged with electronic amplifier. In particular, the discussion of amplifier classes and efficiency is not clear on this page. This could be eliminated from this page, since there is a good discussion of amplifier classes under the electronic amplifier entry.

Agree about the new classes section. There should just be a paragraph about electronic amplifiers in here with a {{main}} link to electronic amplifier. — Omegatron 22:48, 11 January 2006 (UTC)

Rewrite.....

I personally feel that the quality of the article is very poor......i vote to rewrite the article...... and there is no need to merge the classification of amplifiers with electronic amplifiers...

Jayant, 17 Years, India|^(Talk) 05:51, 16 January 2006 (UTC)

• I agree - the whole article on amplifiers needs to have a major re-think as to what it is trying to do, and that should not be skewed towards repeating what is in the Electronic Amplifier article. The main aim should be to describe amplifiers in general, and briefly cover terms (like Gain and Efficiency) using definitions that apply to all types of amplifier. It should be much shorter, but it should link to all the other articles that anyone interested in amplifiers may have come to this page hoping to see, including a separate article on Efficiency of Amplifier Output Stages (which is in a dreadful state as it stands within the Amplifier article itself as I write - errors, no references, partial coverage of the subject, and overlap with other articles. There are 4 goals I feel this article should have:

 * Describe amplifiers in general (balanced coverage of, and try to keep definitions appropriate to: pneumatic, electronic, optical, servo, etc)
 * include a good table/tree structure showing the taxonomy (classification) of types and sub-types of amplifiers 
 * make it clear to the general public (a.k.a. novices) where to find the most important amplifier-related material (e.g. links to how to understand Hi-fi Amplifier Specifications and Jargon), and include alternative plain-English phrases on this page (that can easily be found in searches) that takes them to the geek-phrase that they'd have only known to search for if they had the level of knowledge that probably meant they didn't need to look it up in the first place!
 * be very clear and accurate when it comes to the technical stuff, with good references (remembering present section on efficiency as an example of what not to do).

I don't think it meets any one of them as it stands. Maitchy (talk) 23:50, 10 November 2010 (UTC)

Hub Page

I intend to make this into a hub page with all different sorts of amplifer being breifly described then linked to their own main pages.--Light current 01:23, 29 January 2006 (UTC)

Started tidy up. and transformation to hub page.--Light current 01:31, 29 January 2006 (UTC)

LC, the discussion is a bit too audio-centric. The audio amplifier page could use some content. - mako 02:31, 30 January 2006 (UTC)

Cut from page

Harmonic distortion is fairly easy to measure. The amplifier output is connected to a spectrum analyzer (a device which graphs frequency against amplitude). A pure tone -- typically a sinusoidal signal at 1 kHz -- is then applied to the amplifier input. The largest signal on your analyzer should be the input signal at 1 kHz. You will sometimes see humps at even intervals along the graph at multiples of that base signal. These are the harmonics. The total harmonic distortion (THD) is the sum of these components relative to the signal. --Light current 11:48, 23 May 2006 (UTC)

Information about high power microwave valves

I added information about the continuing advantages of microwave high power valve over semiconductor in the Valve amplifier section. I also added a Reference section and cleaned up the See also secton.Gerry Ashton 18:59, 4 June 2006 (UTC)

Thats good. 8-) But have you considered adding the info to Valve amplifier instead or in addition? PS dont forget to sign your posts!--Light current 18:26, 4 June 2006 (UTC)

Someone clean "linearity" up please

The last paragraph there? I don't even know where to begin.

KjellElec means:

Linearity as such is easily defined, see Wiki. But this statement from the article is a horror and needs to be dealt with in detail or removed:

"Because tubes are significantly more linear than transistors, tube amplifiers do not need as much global negative feedback to achieve acceptable linearity."

Does he compare triodes, tetrodes or pentodes to bipolar, Jfet or Mosfet transistors, and are they low-power types or not? Does he compare components or practical circuits? Tube audio power amps must normally use output transformers, whose wild phase excursions at high frequencies forbid hard overall global feedback in order to stay stable. Thus tube power amps are _forced_ to use a limited amount of global feedback.

End of KjellElec meaning

fwiw there are many tube amps with no global feedback, and some with no feedback whatever —Preceding unsigned comment added by 82.31.207.100 (talk) 20:00, 30 January 2011 (UTC)

Carbon mic amplifiers

http://en.wikipedia.org/enwiki/w/index.php?title=Carbon_microphone&action=edit&section=2 --Light current 19:23, 31 December 2006 (UTC)

Removed text

I removed the following text from the article for the reason that it is mostly unsubstantiated opinion:

In the earlier years of audio, vacuum tubes filled the active device role. Valve amplifiers are widely, but not always correctly, associated with the valve sound. Some claim this sound has more to do with the circuit topology and circuit design of the amplifier, than to the use of valves rather than transistors as the active gain devices. However, this reasoning is not entirely correct. Because tubes are significantly more linear than transistors, tube amplifiers do not need as much global negative feedback to achieve acceptable linearity. While large amounts of global negative feedback are effective for reducing total harmonic distortion (THD) at low frequencies, feedback has downsides such as reduced stability, reduced slew rate, reduced bandwidth, increased high-order distortion, and artifacts such as asymmetrical slewing. In most commercial designs, little attention is paid to these problems, and designers simply attempt to achieve the lowest possible THD.

Alfred Centauri 17:56, 24 April 2007 (UTC)

Metadyne, Magnicon and Magnavolt

I accept the reason given for the removal of the reference to the BBC article on Metadyne but is this a reason for removing the words Metadyne, Magnicon and Magnavolt as well? If so, shouldn't we remove Rototrol too? Biscuittin 11:28, 18 May 2007 (UTC)

If you have a reliable source for Metadyne, Magnicon and Magnavolt, go ahead and add them back (but trademarks might not be important enough to include, if they are trademarks). As for Rototrol, from looking at http://siris-libraries.si.edu/ipac20/ipac.jsp?uri=full=3100001~!219875!0#focus it seems to be a trademark of Westinghouse; perhaps it should be removed. --Gerry Ashton 15:06, 18 May 2007 (UTC)

Definition of amplifier and gain

The current definition of amplifier from this article is: any device that uses a small amount of energy to control a larger amount of energy. I think "amount of energy" should be replaced by "signal" to be more general. Also the definition of "gain" in this article should be similarly generalized. Any comments about this? Roger 15:47, 24 May 2007 (UTC)

I think "power" is better than "signal". Some people may feel "signal" implies communications, and amplifiers are not confined to communication applications. Also, "power" is closer to the physical phenomena that occur in an amplifier than "signal". Finally, gain is usually defined as the ratio of the output power to the input power, so sticking with power will allow a more concise definition of gain. --Gerry Ashton 17:03, 24 May 2007 (UTC)

But the output power can be smaller than the input power (like in a voltage amplifier), so it may not be a small power controlling a larger one. Also there are different types of power gain (transducer, available, etc.) that would need to be mentioned, so it may not be more concise. I think signal is better, because it can mean an energy, power, voltage or current signal. Roger 17:14, 24 May 2007 (UTC)

This article is not confined to electrical amplifiers, so the input and output could be even more general than the examples mentioned by Roger: light, fluid flow or pressure come to mind. A power gain could be computed for any of these. An advantage of using the word "power" would be to eliminate certain quantities that, strictly speaking, cannot serve as input to an amplifier (energy, for example). --Gerry Ashton 17:33, 24 May 2007 (UTC)

Thats true, but a voltage amplifier, for example, could have a power gain of zero or infinity, so it may not always be best to think in terms of power gain. Usually "amplifier" means "electronic amplifier" so I still think signal is a better word. Other non-electrical amplifiers could also be mentioned. Roger 17:58, 24 May 2007 (UTC)

A transformer can increase voltage, but not power, so it is not an amplifier. Also there is nothing wrong with an amplifier having a power gain less than one. No real device has infinite power gain, which is another argument in favor of using the word "power"; it is intuitively obvious that no device can output infintite power. --Gerry Ashton 18:52, 24 May 2007 (UTC)

My point is its misleading to ONLY think in terms of power gain. A voltage amplifier and a simple resistive divider can both have the same power gain, but obviously they are different. And yes, real devices won't have infinite gain , but a MOSFET CS amplifier can have an enormous power gain, but very little voltage gain for example. Roger 19:02, 24 May 2007 (UTC)

I don't have any more arguments to make; I just want to say that I still think "power" is a better word than "signal" and if I don't make any further posts, it means I maintain my opposition to changing the word. --Gerry Ashton 20:08, 24 May 2007 (UTC)

The definition needs to say power, not amplitude of a signal. The current definition (Generally, an amplifier or simply amp, is any device that changes, usually increases, the amplitude of a signal.) is not correct. For example, a simple resistive circuit is a Voltage Divider, which changes the amplitude of the voltage input signal. However, this is certainly not amplifying the signal. Another example is a transformer. A transformer does increase the amplitude of the input signal, but it does not increase the power. You wouldn't consider this an amplifier either. An amplifier is an active device (which requires energy) that can increase the power of the signal (although it may decrease the power). I will wait for more comments before I change it, but I really believe the current definition is incorrect. Better to be correct than be concise and wrong. stemperm 00:31, 19 October 2008 (UTC)

Carbon amps

I think these could do with their own article. There are bits of info on carbon amps dotted about in different categories, but no carbon amp article. Alas no time today. Tabby 16:42, 3 December 2007 (UTC)

Rototrol

A Rototrol isn't an amplifier.[2]. It's a motor-driven power regulator for balancing currents in 3-phase systems. It belongs to the family of big adjustable inductive components used in power distribution. So I removed Rototrol from the amplifier article. --John Nagle (talk) 17:30, 15 December 2007 (UTC)

It looks like the term "Rototrol" has been used for two different devices. The reference above to an adjustable inductive regulator is from a 1994 publication. But US 2470672 , "Rototrol scheme", from 1949 shows a field-modulated generator like a Ward Leonard control. This is probably too much information for the Amplifier article; it belongs somewhere else, under "obsolete rotating electrical machinery" or something like that. I've been putting in a few lines on each obscure amplifier type, but avoiding too much detail. --John Nagle (talk) 18:34, 20 December 2007 (UTC)

This article should be distinguished clearly from "Electronic Amplifiers"

There is massive identity crisis here: this article should be restricted to discussion of ampifliers in general, and properties common to all amplifiers, and not contain undue detail about e.g. power amplifiers. Its scope should be ALL amplifiers. Brews ohare (talk) 17:55, 9 January 2008 (UTC)

I have moved the Power Amp Classes to "Electronic Amplifiers" and combined it with the already existing extensive discussion there. However, it would be desirable to put it all into a Power Amp article. Brews ohare (talk) 18:37, 9 January 2008 (UTC)

Moved classification scheme to discussion of that name in "Electronic amplifiers" Brews ohare (talk) 19:09, 9 January 2008 (UTC)

This entire article contains so many weak sections that it makes one weep. Brews ohare (talk) 00:22, 10 January 2008 (UTC)

this article lacks car audio/home entertainment information

definitely lacks in this category. I would like to see amplifier class, types of connectors, RMS ratings, number of channels, etc. It only briefly touches on "Efficiency" and never stating why it is more efficient or what each class does and how it works. 12.215.147.98 (talk) 04:41, 21 January 2008 (UTC)X

For class definition, have a look on Electronic amplifier. Yves-Laurent (talk) 07:08, 21 January 2008 (UTC)

Could use some pics

Right now the article looks like a wall of text. Some pics would really help to break the monotony. —Preceding unsigned comment added by 72.186.242.122 (talk) 03:47, 5 June 2008 (UTC)

I agree to that. A link at the bottom of the article, to a page with images for each type of the most types of amplifiers, mentioned below, was taken down by extreme causes. —Preceding unsigned comment added by 83.248.161.207 (talk) 10:06, 4 November 2008 (UTC)

amplifiersite.com link

I have twice deleted an external link taking the reader to amplifiersite.com for the reason that this site appears to be controlled by one author and is not subject to outside review or correction. Binksternet (talk) 17:10, 3 November 2008 (UTC)

How come you omit a link with complement and relevant info in regards to public interest (relating to what is "most popular" and common), to an article, Amplifier, with foremost theoretical approach (not at all wrong in itself). I do not accept your action and may I believe it was done by you in subjective moods, not by what is infact generally considered as qualified. Besides, and in the view if only for the issue just above, you seem to act on people in a way that cannot be justified in my view (like explaining/post-justifying because of emotional triggering etc). In my humble opinion, such an editor should carefully review his or her motives, whether they reflect personal attitudes vs what is considered, as mentioned above, of general and public interest yet considered as qualified. —Preceding unsigned comment added by Colorbow (talk • contribs) 17:38, 3 November 2008 (UTC)

I have nothing against you or your website link. I looked at it and the parts I have experience and knowledge about appear fairly accurate, with only minor mistakes that I was able to spot, such as the incomplete reasoning for why there is a greater requirement for high output power in subwoofer amplifiers. The reason I deleted the link is that the website has no scholarly basis, no ability to check facts. It appears self-published and isn't verifiable. See WP:SELFPUB. Binksternet (talk) 18:08, 3 November 2008 (UTC)

Then there are tons of links in wikipedia articles that are unverifiable, in my view although I don't demand any theoretical support etc for the content in pages I visit, even though such support is provided or not in the first article. If facts are to be questioned, as anywhere, with or without references, it can be searched for.

Even articles in Wikipedia itself may be full of subjective values and subtle descriptions yet with little substance, therefore impossible to verify generally, such as in the Audiophile article. Why do you demand a support by "scholarly basis" unless the content is obviously inaccurate? Why does the content of any linked page have to have access, directly or indirectly, to calculations or mathematics that are already presented in the base article, especially if the linked at content doesn't aim at provide only further textual content. Why does a content in where a link points to have to be complete in such a way that if just minor part in the overall level of facts, may be missing, then all must go. There are also tons of incomplete articles in Wikipedia, some even accepted without marks.

If other links added by other editors aren't appropriate, they should be taken out. It's not a good argument to ask for leniency for your link because of a bad example elsewhere in Wikipedia.

The amplifiersite.com page appears to use copyrighted images taken without permission from other sources. Though this practice is widespread on the internet, and can be useful as a method of showing pan-industry trends, Wikipedia cannot support copyright violations.

If you have so much desire to improve the various amplifier articles here on Wikipedia, why not simply edit the body of text in the articles you see needing help? Binksternet (talk) 13:28, 4 November 2008 (UTC)

If instead having the issue looken at generally, unless it is clearly and without doubt obvious that copyright violation is done somewhere, then any support is wrong. However it is impossible to make such estimations, or judgements, just by chance. An enormous number of links in Wikipedia articles could be taken away immediately, because of such guard principals, which does not interfere with the fact that some links actually, not only should be, but also have to be removed if and when observed.

Wikipedia has achieved, or established, a kind of an autonomous status on the internet, but not always deserved. Articles can be edited and improved etc, but chance is that some people not only may improve the content which of course is the prerequisite of Wikipedia's existence, but also may remove true content, which also happens.Colorbow (talk) 17:16, 4 November 2008 (UTC)

I have to agree with Binksternet. Linking another self-published site makes this article worse, not better. amplifiersite.com seems like an informative site, but it appears to be just another non-notable opinion that cannot be verified. Best to leave it out. See WP:EL for more reasons. / edg ☺ ☭ 13:48, 4 November 2008 (UTC)

One more general point: a link like amplifiersite.com takes the reader to a page that competes on some level with Wikipedia. Rather than listing such links, the articles here should be strengthened with whatever additional breadth of coverage or deep detail focus is required to make them more fulfilling for the Wiki reader. A link that has the same depth of coverage as the related Wiki article isn't what will help Wikipedia in the long run. What helps are links to reliable sources that are MUCH deeper or broader in focus. Binksternet (talk) 23:50, 4 November 2008 (UTC)

I think, that sounds acually strange. How can it compete? If it "competes", it has to be, whether admitted or not, standing out with any kind of quality, substance etc. It is impossible that Wikipedia would demand or ultimately hold an authority of knowledge above everything else. Why should it have to? For whom? If internet is seen as a tool in a public interest, then internet serves the public with what they search for. As we all know, for the present time, Google pretty much owns the internet. Google have secret algorithms that calculates website ranking and while Wikipedia is if not on top, very often among the top results, it is sometimes not even on the first page. Because the Google algorithms sometimes say, there are other websites that are better than Wikipedia for the given search term or phrase. Google does not generally favor Wikipedia, at least it should not. It should favor pages with approved content. I have seen Wikipedia articles sometimes among the top although the content of those articles weren't worthy that ranking. It may happen to new articles. After I while, Googles pushes the articles back.

If competition is mentioned in a way that puts a strict border holding Wikipedia above anything else (=certain politics), then some links would not be welcome or not even allowed, because they "compete". Binksternet wrote "What helps are links to reliable sources that are MUCH deeper or broader in focus". It is close to impossible to meet up such requirements for making links for articles in Wikipedia that hold a very qualified and theoretical level. So how would those articles be complemented? Unless only "scolarly basis" as term is a definition for the linking criteria, it only matches up to the way of "traditional" scholarship claims about how anything is valid, as for science. Many articles in Wikipedia don't linearly reflect the way people are interested in them. Some are way to theoretical which is not wrong itself, but when they lack content that people search for, they are not complete. Most websites have images. Wikipedia don't have many images. No articles will be even near complete as long as they more relate to the theoretical base no matter how "deep" and textual they are. People want images and they may want personal reflections (=that sometimes may be close to no scholarly basis). Images are needed, they show what it is about. They provide better understanding to the subject. Therefore, external links should not be looken at as competing to Wikipedia, rather a complement. Competition may indeed enforce improvements. Colorbow (talk) 01:50, 5 November 2008 (UTC)

I don't think "competition" is a concern. However, a Wikipedia article on amplifiers should contain the same level of information as amplifiersite.com, and it should be verifiable and with a neutral point of view. Per Wikipedia:External links, a valid external link for the Amplifier article might be a unique resource that provided neutral, accurate information that for depth or copyright reasons could not be included on Wikipedia. Per Wikipedia:Reliable sources, if there were some way to confirm that amplifier.com was authoritative beyond its writers opinion, it could at least be used for citation purposes. However, since it appears to be one person's opinion backed by nothing, it's useless. / edg ☺ ☭ 01:42, 5 November 2008 (UTC)

Yet still, there are articles in Wikipedia with subjective opinions, but since all people have more or less different opinions etc it cannot always be determined what is right or wrong, especially if a type of subjective opinion is already widespread. I do not agree that something is useless because it is not backed by any reference, it might depend on the content's complexity. If readers always question things, then any reference or source can be questioned too if it is not further referred to. I do think this discussion projects different values and I think there is a kind of bureaucratic loop in the arguments. I will

not contribute to Wikipedia more than very occasionally or when something written is clearly wrong. Colorbow (talk) 04:53, 5 November 2008 (UTC)

Software Audio Amplifier of Sound Files

I was hoping to find info in this article in regard to software that is capable of increasing the intensity or audio of recorded sound files. I am no "expert" in this regard but it seems to me that the way to do it is to increase the intensity of the sound waves. I am also looking for software that is capable of removing background noice such as the hum generated by a recorder or the hum over an audio system when recording audio played over an audio system such as inside an audiotorim. —Preceding unsigned comment added by 99.56.160.53 (talk) 21:03, 28 February 2010 (UTC)

Isn't software incapable of amplifying? Seems at first sight that it can only direct hardware to amplify Tabby (talk) 11:49, 7 June 2010 (UTC)

Valve Glow

"The glow from four "Electro Harmonix KT88" brand power tubes lights up the inside of a Traynor YBA-200 guitar amplifier"

having played with KT output valves, that piccy looks nothing at all like valve glow. Looks like someone put some lightbulbs under them. Tabby (talk) 12:10, 7 June 2010 (UTC)

Valve heaters glow dull red Tabby (talk) 15:09, 7 June 2010 (UTC)

deletion

Deleted "The efficiency of the amplifier limits the amount of total power output that is usefully available" as I dont really see how that can be true, except in unrealistically extreme cases. Tabby (talk) 15:05, 7 June 2010 (UTC)

Class AB vs Class B

Someone makes a blatant claim in the article, that class B amplifiers are not acceptable for audio due to crossover distortion. This idea is discussed in Douglas Self's book on amplifier design where he suggests class B if preferable to class AB, but there seems to be some divergence in the exact use of class B vs class AB. Self mentions that no bias at all, should probably called class C.

I built a little audio amplifier somewhere around 2000 that ran as class B. It sounded great - there are ways to handle the crossover issue in class B. 82.31.207.100 (talk) 20:09, 30 January 2011 (UTC)

Defining property

Says in the lead, "The defining property of any amplifier is that it has a gain greater than one." This is uncited. By this definition, a transformer could qualify as an amplifier. --Kvng (talk) 14:20, 20 December 2010 (UTC)

Linear amplifier and Electronic Amplifier us an increase in power as the defining property. I believe this is correct and have made the change. --Kvng (talk) 15:07, 20 December 2010 (UTC)

Good catch. Thanks! Binksternet (talk) 16:54, 20 December 2010 (UTC)

The statement is correct iff Gain is defined as Power Gain.99.2.69.235 (talk) 06:27, 7 September 2012 (UTC)

Output Power Ratings

It seems a major figure of merit haas been totally omitted from this article, the Output Power rating, and all of its various incarnations, eg., Peak Power, RMS Power, Music Power. An explanation of these basic parameters should be included in this article on amplifiers. — Preceding unsigned comment added by 99.2.69.235 (talk) 06:24, 7 September 2012 (UTC)