Talk:Amplifier

message: The example circuit in the introduction needs a capacitor (or some other high-pass filter) connected between the collector and base of Q3 in order to provide frequency compensation. The circuit as drawn without the aforementioned capacitor has way too much open loop gain in the VA stage especially at high frequencies. This will cause distortion and instability. Relying solely on the Ccb or so called "Miller" capacitance of Q3 to provide adequate local negative feedback is usually considered a poor choice in design practice.     — Preceding unsigned comment added by 24.218.178.56 (talk) 01:16, 30 December 2011 (UTC)
thread_title: Example Circuit

message: I've merged (from a different IP) and then completely rewritten the introduction to class E/F. i hope it clearer now. I've left the remaining description, although in my opinion it is not clear at all, and at time absolutely WRONG (seems to be a transcription from some source by someone who doesn't understand all the details). I recommend removing most of the remaining part in class E/F except my introduction ;)
I didn't remove any existing errors in the old text, because someone is stupidely reverting all my changes when i 'remove' anything... the blantant errors are: class E doesn't output square wave. it is possible to modulate the signal with class E. the text on class F is complete crap. i would remove it completely.
: Your IP changed.  See User talk:217.132.20.249 for your edits on electronic amplifiers.  You should just get an account. — Omegatron 22:25, 31 March 2006 (UTC)
thread_title: Class E/F

message: I think class A amplifier section is wrong. Firstly, a class A amplifier is not another name for an operational amplifier, as the text may suggest. And the diagram is misleading, drawing a BJT connected without any base-emitter current limiter. A BJT with a current generator in the emitter and a load in parallel is the standard way to depict it. 
If people agree, I can modify the section. 
Romano (talk) 16:06, 11 January 2011 (UTC)
replies: text: I agree that the mention of op-amps is unhelpful, so just remove it. There is an "Operational amplifiers (op-amps)" section, and I do not think it needs any mention of "class". The diagram is problematic: yes, it's wrong, but exactly what alternative would be better? The point of the diagram is to give a very vague overview, while showing accurate i/o waveforms. I cannot think of any simple improvement that would not reduce its accessibility for general readers. There perhaps could be some mention like "bias circuit not shown", but the same applies to some extent in all the "class" diagrams. Johnuniq (talk) 00:48, 12 January 2011 (UTC)
thread_title:  Class A amplifier problems 

message: Who first used "Class A" "Class B" etc?  —Preceding unsigned comment added by 96.224.72.5 (talk) 21:18, 12 May 2011 (UTC)
thread_title:  Etymology of "Class A" 

message: The article uses both terms rather randomly and sometimes confusingly. It would clean things up if we chose one or the other. Can we do that? I don't care which really. --Kvng (talk) 01:38, 10 June 2011 (UTC)
thread_title:  Valve vs. vacuum tube 

message: The circuit diagrams for A and C are the same. Why do they differ? Is the transistor driven in another manner? Could someone write a sentence to clarify this?
-- 178.83.12.182 (talk) 17:51, 20 September 2011 (UTC)
replies: text: The tet does explain the difference. The waveforms would be more illustrative if they were properly referenced to 0 volts. It's hard to see how teh Class C amp can have an output that swings negative with respect to ground... --Wtshymanski (talk) 18:51, 20 September 2011 (UTC)
thread_title: A C distinction 

message: I put a citation needed on the claim that most "quality" op amps have class A output stages. Op-amps, even very good ones, have push-pull output stages. When we use a word like "quality", we create the start of a No True Scotsman argument. What kind of quality? Can we put some kind of number on it? This is someone's opinion that op-amps have to have class A output stages to have  good quality.  Whoever believes this claim should be easily able to cite part numbers and data sheets to substantiate it, as well as other third-party documentation which shows that those op-amps are of superior quality: measured low noise and distortion figures, and other relevant qualities, like good power-supply rejection ratios, low offset currents and voltages, decent slew rates, etc. 192.139.122.42 (talk) 22:45, 2 October 2012 (UTC)
thread_title:  Added citation-needed for op-amp claim 

message: This article was moved from Electronic amplifier to Amplifier per Talk:Amplifier_figures_of_merit#Amplifier_topic_organization. Olli Niemitalo (talk) 07:54, 31 January 2013 (UTC)
replies: text: This article is still sorting on "electronic amplifier". Is that what people want? Not sure what the best decision is here. Jason Quinn (talk) 04:48, 30 March 2013 (UTC)
thread_title:  Article moved from [[Electronic amplifier]] 

message: This may be my being to pedantic but the article begins
"An electronic amplifier, amplifier, or (informally) amp is an electronic device that increases the power of a signal."
But I can imagine a circuit where the loaded voltage of a circuit is multiplied but then fed into a high impedance load so it draws very low power (consider attaching an amplifier to an oscilloscope, negligible power out of the amplifier but the voltage has increased.)  Is it therefore accurate to say that it is power that is increased? RJFJR (talk) 16:14, 3 May 2014 (UTC)
replies: text: Yeah, most definitions   1,  2,   3,  4,    5  don't seem to limit "amplifier" to devices that increase the power of a signal, but also include devices with voltage or current gain.  One that I like says "a device that uses an external power source to increase the strength or magnitude (power, voltage or current) of an electrical signal".  --ChetvornoTALK 20:19, 7 June 2014 (UTC)
thread_title:  amp always increase power? 

message: The term Amplification redirects here.  Wikipedia should include somewhere a history of the important concept of amplification.  The invention of the amplifying vacuum tube (the Audion or triode) in 1906 created the field of "electronics" (the study of active (amplifying) electrical devices) and made possible all of information technology:  long distance telephone lines, practical radio broadcasting, television, talking motion pictures, audio recording, telemetry, computers, networking, etc.  I'm prepared to write such a history, but I don't know where it should go.   This article is already bloated, and it focuses on a narrower topic: electronic amplifiers, rather than the concept of amplification in general.  Gain focuses narrowly on definitions of voltage and power gain.  Does anyone have any thoughts about where this history should go?  Should there be a new Amplification or History of amplification article? --ChetvornoTALK 07:57, 6 June 2014 (UTC)
replies: text: I think your proposed information should go into amplification which would therefore be changed from a redirect into an article. Binksternet (talk) 14:30, 6 June 2014 (UTC)
replies: text: Thanks, I think that's probably the best idea.  Another possibility that occurred to me is to include it in the Electronics article, since the invention of amplifying devices was pretty much synonymous with the birth of electronics. --ChetvornoTALK 20:27, 7 June 2014 (UTC)

text: I know what you mean.  Non-ideality is reality.  Like that broken "period" key on your keyboard that almost never works.  Dicklyon (talk) 00:36, 31 August 2014 (UTC)
thread_title:  History of amplification 

message: I deleted 'The amplifier is often described as the heart or the nervous system of a microphone or loudspeaker' since
# in a lifetime of electrical & electronic engineering I've never heard anyone say it
# a newspaper is a long way from being a reliable or accurate source
# its typical journalistic fiction
86.29.7.158 (talk) 07:18, 20 April 2015 (UTC)
replies: text: Thanks. I see that the dubious text was added as part of a series of edits on 23 February 2015, and some of the other text should be examined. Johnuniq (talk) 09:47, 20 April 2015 (UTC)
thread_title:  Heart / nervous system 

message: There should be a section dealing with the history of amplifiers, such as when the amplifier was invented. Blaylockjam10 (talk) 08:04, 28 June 2015 (UTC)
thread_title:  The history of amplifiers is missing. 

message: I'm going to (slowly) start to clean this article up, feel free to help if you want to. The things I think need work:
*What are we actually talking about? Is just a transistor an amplifier? Is a single op amp an amplifier? A transistor or op-amp with the surrounding circuitry to make it function? Is an entire audio power amplifier an amplifier? I suspect the answer to all these questions is yes, but we need to constrain the scope of the article: I think it would be best to write the article about circuit level or smaller (where circuit level is around the size of :File:Amplifier Circuit Small.svg)
*How are amplifiers categorised? Surely solid state/valve/magnetic isn't the same sort of categorisation as op-amp/fully differential or video/oscilloscope vertical/microwave? I propose splitting into categorisation by active device (solid state, valve, magnetic, negative resistance), {categorisation by architecture [wrong word?] (op-amp, differential amp, distributed)} (not sure about this) and examples of application specific amplifiers with their ideal properties (video, oscilloscope, microwave, instrument).
*Reduce redundancy: some of the article repeats other parts -  there are two sections containing functions of amplifier.
*References: it would be nice to have more of the article referenced, including the bits that are (to experts) obvious
What does anyone think? I'm going to go ahead and start to implement some of these changes, feel free to either help or stop me! —  crh 23  (Talk) 19:20, 18 June 2016 (UTC)
replies: text: Basically, I'd like to get this up to the good article criteria. #1 should be achievable without too much effort, #2 is currently a fair way from achievement (see scientific citation guidelines, #3 is close, maybe needing a little more attention paid to summary style in some section (maybe not). I doubt #4 will be much trouble, nor will #5 (judging from recent activity, unless everyone suddenly gets very passionate about amplifier design). As to #6, we could do with a nice image to place at the top, maybe :File:Operational amplifier.svg or something like :File:LM741CN.jpg (which is already included in the page). —  crh 23  (Talk) 20:53, 18 June 2016 (UTC)
thread_title:  Sprucing this article up  

message: Hello fellow Wikipedians,
I have just modified  on Amplifier. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
*Added archive https://web.archive.org/web/20040610023359/http://www.qscaudio.com:80/support/library/papers/amptalk.pdf to http://www.qscaudio.com/support/library/papers/amptalk.pdf
*Added archive https://web.archive.org/web/20041030161938/http://www.caraudiomag.com:80/specialfeatures/0111cae_anatomy/ to http://www.caraudiomag.com/specialfeatures/0111cae_anatomy/
*Added archive https://web.archive.org/web/20070929062038/http://www.coldamp.com/opencms/opencms/coldamp/files/Class_D_audio_amplifiers_White_Paper_en.pdf to http://www.coldamp.com/opencms/opencms/coldamp/files/Class_D_audio_amplifiers_White_Paper_en.pdf
When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at ).
Cheers.—InternetArchiveBot (Report bug) 00:15, 12 October 2016 (UTC)
thread_title:  External links modified 

message: This is a deep subject.  "Electronics Engineers' Handbook" has a 146 page chapter on amplifiers and oscillators, and *that* is still an overview (ok, so maybe 40 of those pages are about oscillators). Any specific details must be spun out to other articles, and this article should be only a 20,000 foot overview of the field. Even so, there's so much that hasn't been touched on here - stability, load lines, economics! Luckily a lot of the details are available already in other articles, we don't have to go on about tube sound here, for example, just point at it.  --Wtshymanski (talk) 16:53, 7 May 2017 (UTC)
thread_title: Overview, overview, overview

message: Hello fellow Wikipedians,
I have just modified 3 external links on Amplifier. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
*Added archive https://web.archive.org/web/20110514001329/http://www.rane.com/par-a.html to http://www.rane.com/par-a.html
*Corrected formatting/usage for http://www.qscaudio.com/support/library/papers/amptalk.pdf
*Corrected formatting/usage for http://www.caraudiomag.com/specialfeatures/0111cae_anatomy/
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
Cheers.—InternetArchiveBot (Report bug) 22:26, 19 May 2017 (UTC)
thread_title:  External links modified 

message: The 3rd paragraph of the introduction was recently changed from:
:"The first practical electronic device that could amplify was the triode vacuum tube, invented in 1906 by Lee De Forest, which led to the first amplifiers around 1912."
to:
:"After electro-mechanical signal repeaters, such as the Shreeve repeater of 1904, the first practical and entirely electronic device that could amplify was the triode vacuum tube, invented in 1906 by Lee De Forest, which led to the first amplifiers around 1912."
The reference to "electro-mechanical signal repeaters" is to speakers driving carbon microphones to make a crude electroacoustic amplifier, which had very limited use as telephone line repeaters during the first two decades of the 20th century. 
While they are quite properly described in the History section, I think mentioning them in the introduction gives WP:UNDUE WEIGHT to this trivial dead-end technology.  Carbon repeaters were truly horrible amplifiers, being insensitive, having sharp resonance peaks, DC offset problems, and introducing noise (the "carbon roar").  They were only used in a limited way in telephone lines, and had almost no usage in other applications of amplification.   There are many more notable points about amplifiers in the article which should be mentioned in the introduction before mentioning this device. --ChetvornoTALK 21:50, 3 June 2017 (UTC)
replies: text: I also think it is blatant WP:UNDUE WEIGHT to put mechanical repeaters on a par with tubes by saying in the History section   "The Shreeve mechanical repeater and the vacuum tube were the only amplifying devices, other than specialized power devices such as the magnetic amplifier and amplidyne, for 40 years."  Even if it lingered on in a few specialty applications like hearing aids, the mechanical repeater was virtually obsolete by the early 1920s, replaced by tubes. --ChetvornoTALK 03:20, 5 June 2017 (UTC)
thread_title:  Why mention carbon repeater in intro? 

message: :The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.
The result of the move request was: not moved. (closed by non-admin page mover) – MaterialWorks 20:11, 11 September 2023 (UTC)
replies: text: Amplifier →  – 1) The article opens with the hatnote: This article is about electronic amplifiers...
2) Then begins with an immediate disambiguation: An amplifier, electronic amplifier, ...
3) It is the main article of :Category:Electronic amplifiers
4) The category :Category:Amplifiers is subdivided into the two subcats :Category:Electronic amplifiers and :Category:Mechanical amplifiers, the latter of which has its own main article.
Summary: All of the above indicates that the best title for this article is "Electronic amplifier" Gjs238 (talk) 16:11, 4 September 2023 (UTC)
thread_title:  Requested move 4 September 2023