Talk:Audio power amplifier

Illustrations

The images shows amplifiers with toggles and dials, I think a better illustrations would be a [1] or simmilar. — Preceding unsigned comment added by Elendal (talk • contribs) 05:15, 19 October 2021 (UTC)

Transistor amplifiers

Practical transistor amplifiers were not only due to cheap solid state devices but early transistors also had issues with mid-band gain, alot of this issues were first cataloged by RCA (see specifically the work of Larry Giacoletto) —The preceding unsigned comment was added by Mattpalmer84 (talk • contribs) 2006-04-18T07:27:24.

Levels and comparisons

I'd like to edit the introduction of this article because it makes what I believe are two mistakes.

• (Refering to an amplifier's low power input levels) By "low power" it is meant that the signals are usually limited to those required to drive headphones (less than 500 mW).

The input stages to most audio amplifiers are designed to handle signals weaker then headphone levels. Most audio amplifiers require their inputs to satisfy line level signal levels.

• While the input signal may be only a few hundred millivolts, the power amplifier's output may have a power of many watts.

This sentence mixes incompatible units: volts and watts. I think "millivolts" should be changed to "milliwatts".

— Ke6jjj 18:47, 4 December 2006 (UTC)

Agreed. An audio amplifier connected to a phonograph's magnetic cartridge receives mere microwatts. Using terms like "low" and "high" should probably be avoided altogether: look at what happened with the RF band names: very high, super high, etc. — EncMstr 20:25, 4 December 2006 (UTC)

Main page?

should this be the main page on audio amplifiers from which all other articles on audio amps fork off?--Light current 22:31, 31 January 2007 (UTC)

• I Agree! A lot of what is said applies to electronic amplifiers in general, or at least musical instrument amplifiers etc. Yet the Electronic amplifier page is pretty big and overloaded as it stands (see my discussion in Linear amplifier talk about merge/reorganise etc). There still should be a place for history of (significant) audio amplifier developments, including the Williamson and more. Perhaps it could morph into that?? Maitchy (talk) 05:44, 4 June 2011 (UTC)

• Agreed.Comment. There are at least buffer amplifiers, preamplifiers, power amplifiers, and some application-specific amplifiers. I'd like to see them indexed here as sub/sections, with separate articles when necessary. Now the lack of connection between those articles makes them quite a mixed bag. Olli Niemitalo (talk) 05:42, 29 September 2012 (UTC) Edit, Olli Niemitalo (talk) 21:27, 1 October 2012 (UTC)

• Disagree This page is currently about audio power amplifiers. If you want to create a main article for audio amplifiers, first rename this one. Alternatively, there seems to be ample room to make Amplifier the main article. — Preceding unsigned comment added by Kvng (talk • contribs) 00:07, 1 Oct 2012 (UTC)

Renaming this article to Audio power amplifier would probably be a good move in any case. I bet audio power amplifiers are called simply "amplifiers" more often than "audio amplifiers", anyway, so not much value would be lost on the name of the article. As to where to collect different kinds of audio amplifiers (preamps etc.), Electronic amplifier would do the best, I now think. Maitchy says Electronic amplifier is overloaded, but that may be remedied by sectioning the article to kinds of lists, "by technology" and "by application". Olli Niemitalo (talk) 21:27, 1 October 2012 (UTC)

I have renamed this article. I don't have a grand organization scheme in mind for this topic. I find that if you roll up your sleeves do work improving the individual articles, opportunities for organizational improvements begin to emerge naturally. -—Kvng 22:10, 1 October 2012 (UTC)

Audiophile bias

There are times when EQ might work: low SPL listening (fletcher-munson), bad mixing, achieving flat response to 20 hz. Many homes contain carpet and furniture which changes the power response. I would agree that an EQ, preamp, amp, should ideally be separate.

I agree as well, EQ should not be part of this article. Ohgddfp (talk) 14:41, 28 November 2013 (UTC)

EQ is almost mandatory in dense apartments; I used to get complaints from 6.5" B&W speakers.172.132.137.91 08:02, 22 April 2007 (UTC)

Remember that there is also a direct arrival sound from the speakers. EQ in an attempt to fix room reverberation and acoustics unfortunately undoes the frequency balance for the direct arrival sounds. How to fix both? Yes, most "audio power amplifiers" are integrated with control preamplifiers that have tone controls. But I think EQ and tone controls should be part of a section on sound reproduction in general. So for the above reason, tone controls, EQ and room acoustics should not be part of this article. Ohgddfp (talk) 14:41, 28 November 2013 (UTC)

People Discrimination is not legal and against Wikipedia rules

I noticed that some editors (see at History of this page) discriminates Latin American engineers and researchers. Frequently Oscar Bonello of Argentina is discriminated although he is a Fellow member of AES, New York. He is probably the most respected researcher in Audio Engineering and Acoustics in Latin America. He teaches at several universities with thousand of graduated engineers or doctorate students. If you are not convinced, please do a test. Go to the AES website (www.aes.org >> awards) and get a list of Fellow members. Take a few names, of well known researchers (all with the same FELLOW degree). Then go to Wikipedia using the “Google search option” and search for names between quotes; you will find:

• • Leo Beranek He has 265 entries in Wikipedia
  • James Moir He has 98 entries
  • Robert Moog He has 166 entries
  • Ray Dolby He has 45 entries
  • Oscar Bonello He only has 15 entries

Then when an editor erases any contribution of Bonello as “promotion” please note that he lies; it is a simple act of discrimination, that is unfair and privates the Wikipedia readers of knowing his important contributions. I ask to his many past students to edit articles to help that the Latin American Science and Engineering will be known at the level it deserves. RobertTanzi —Preceding unsigned comment added by RobertTanzi (talk • contribs) 04:39, 11 March 2009 (UTC)

The addition is hardly being removed for any kind of nationalism. It does seem overly promotional. It would be a much more appropriate addition to an article about amplifier design, not a general article like this. —EncMstr (talk) 05:55, 11 March 2009 (UTC)

What I want to see from any Bonello entry to the English-language Wikipedia is a basic appreciation of English grammar, a sense that the text hasn't been copied and pasted from somewhere else, a quantified and accurate description of technical achievements and an absence of overly optimistic and promotional peacock words and concepts. The Bonello text under discussion violates these minimal guidelines. In the text, there are bracketed numbers such as [7] and [8] which tell me that this text was used somewhere else with footnotes. Those footnotes weren't brought here. We have phrases like "far better distortion measurements than valve amplifiers, at low cost and with high power" that lack quantities: how much better? What low cost? What power level? Finally, the term "Distortion Multiplication Factor" was introduced without any explanation. These problems should be addressed before the text is worthy of inclusion. Binksternet (talk) 06:28, 11 March 2009 (UTC)

Further to that, I would like to add that some indication of notability for this research/techniques should be present. Given that the material is continually being re-added by Bonello himself or by his co-workers/co-researchers (on a number of articles, not just here), there is a strong conflict of interest here. We currently have no indication that anyone else in the world knows or cares about his contributions (I'm not saying that no-one does, just that we don't know about it). Oli Filth^{(talk|contribs)} 09:22, 11 March 2009 (UTC)

I think I was the first to notice Bonnello's contentions and claims and with an open mind, I helped him re-write his submissions and gave him advise so as to avoid falling into these pitfalls. Unfortunately, it appears that more than a year later, he and his supporters continue to push for his name being mentioned and associated with digital audio technologies at Wikipedia English more, it seems, than any other engineer in our audio history. Therefore I have to disagree; the claim that he and others are being discriminated at WP is simply unsubstantiated. Jrod2 (talk) 14:26, 11 March 2009 (UTC)

I will speak for myself of course. Bonello has many editors beacuse he teaches in several universities, and many engineers or post doctorate people remember him and wishes to have it at Wikipedia (he is like a Latin American flag) Bonello do not write anymore for Wikipedia because the discrimination problem (very often discrimination is not only for him. Very often all the people (USA born including) he comments are banned, see History of FM Broadcasting, by example) Probably some explanations can be improved. But erasing it is not the way...

Some comments (like Oli: " We currently have no indication that anyone else in the world knows or cares about his contributions" are ofenssive... Oli, please you are speaking of an AES Fellow... You think that AES uses to deliver Fellowship award like candies? ) Other cooments like Jrod2 are real. If I revise the history I see that Jrod2 very often help to improve articles. Thank you for your help. Can you help us in the future ? Please note that during the last months Bonello (nikname OscarJuan) do not contribute to Wikipedia. All editors at this moment have the Spanish or Portuguese as native language. But since English is the international lenguage we must write in English (Wikipedia only is complete in Englisg with 2,7 million entries)

Some comments like the " bracketed numbers" appears as the resulta of continuous erasures and restorations. Of course we can improve it

In brief: since Wikipedia must be a collaboration area I personally ask you to improve the article redaction, not to erasure/restore for ever

Can you suggest me the best procedure to correct one by one the articles ?

Regards, Rodolfo Mita —Preceding unsigned comment added by RodolfoMita (talk • contribs) 21:17, 11 March 2009 (UTC)

Given the number of single-purpose accounts that are involved in this, I've now started a case at Wikipedia:Sockpuppet investigations/RobertTanzi. Oli Filth^{(talk|contribs)} 00:57, 12 March 2009 (UTC)

Dear Oli_Filth As result of your “ contributions” now two articles at Wikipedia are blocked for editing (for all editors) One is Audio Amplifier that need urgently a good editor… The statement that Lee De Forest invented the audio amplifier do not support analysis. Please read the Radiotron Designer Handbook in order to see that the triode valve invention is not the same as an amplifier device like you show at the photos. I only do this comment to show the necessity of good technical editors in Audio / Acoustics at Wiki.

Since I found about 50 wiki articles in this field that need editing, I ask me if you are planning to block all them. Probably to keep untouched the lack of references and amateur personal opinions that it contains. Sometimes you recognize a good editor because you keep the good edition done by OscarJuan (Oscar Bonello ) in April 2008 “ Further Developments …” with several references. But in order to be grateful with Oscar Bonello you erase him (only him) of his own edition ! leaving unmodified all the rest of the article… It is one of the best examples of discrimination I ever seen…

Of course you are right with the concept of “single purpose editors” But it is due that all member of ASA, AES and probably IEEE have received by mail information about the discrimination of one of our Fellows members and then we all are contributing to stop Wikipedia. Probably during the next months all audio / acoustics articles must be blocked discouraging new editors to improve it. Is it what you want ?

Please, let me know what is your idea about this matter Regards AlbertoReiss --AlbertoReiss (talk) 00:24, 8 April 2009 (UTC)

Hello.

These two articles (Audio amplifier and Architectural acoustics) have been protected from edits by new users and anonymous IP users (see WP:SEMI). It was not me who did this (I am not an administrator), but it was me who reported the problem of excessive sockpuppeting, vandalism, and edits against consensus.

If there are problems with this article (or other articles), then let's discuss and fix them (on the appropriate talk pages)! I have no problem with that. What I do have a problem with, however, is a team of editors whose only purpose is to get Oscar Bonello mentioned all over Wikipedia (see Wikipedia:Sockpuppet investigations/RobertTanzi/Archive). If there is no more of that, then I think we can make progress.

When I was clearing up all the Bonello promotion, I didn't at first notice that the "further developments" section was by Bonello (as it was added via an anonymous IP [2]). At the time, my main concern was to eliminate the self-promotion. I'll read that section again, and see if anything needs to be changed. Regards, Oli Filth^{(talk|contribs)} 17:32, 9 April 2009 (UTC)

Dear Oli: Ok but still remains the central point. My idea is to improve edition of some new audio articles. But prior to do that, I wish to now if you have a list of banned people. Can I mention Ray Dolby ? Can I mention Dr Nepomuceno ? (Brasil) Can I mention Prof Bonello (Argentina) ? You said: I was clearing up all the Bonello promotion But as RoberTanzi DEMONSTRATED (see above "People Discrimination" ), Bonello do not have promotion (he is the less mentioned of other AES Fellows) Then prior to use my time to improve Wikipedia articles I need to know if Bonello and other people must be censored or directly banned for Wiki. Of course when I cite a person always cite a peer review reference. Your reply will be important in taking my decision (and problably some other future audio editors have now similar questions) Regrads--AlbertoReiss (talk) 00:42, 12 April 2009 (UTC)

There is no "list of banned people"! But work should only be mentioned where it's relevant, notable, and isn't against consensus. By "consensus", I refer to a broad range of editors who have all agreed on a decision on an article talk page (see, for example, the long discussions about Bonello at Talk:MP3). Bonello was promoting himself - he added himself to a whole range of different articles. This coincided with a set of single-purpose editors who continued to restore the material when it was removed, and then began vandalising and other performing inappropriate actions.

Because of this history of problems, I would suggest that Bonello should not be added to an article unless it has been thoroughly discussed on the appropriate talk page beforehand. Oli Filth^{(talk|contribs)} 00:52, 12 April 2009 (UTC)

Transient Intermodulation Distortion

About: "TIM did not appear at steady state sine tone measurements, helping to hide it from design engineers prior to 1972." There is an "elephant in the room" here that some readers may wonder about, and therefore should be included in this article. It's true that harmonic distortion tests would not likely reveal all problems. But testing for Intermodulation Distortion on the other hand reveals the same deficiences that a TIM test reaveals, PROVIDED that the heavy dose of ULTRASOUND in a regular TIM test signal is REMOVED. This is why using the preamp to get rid of this ULTRASOUND by way of a reduced bandwidth, as your article already mentions, is part of the solution to get rid of transient intermodulation distortion, AS CAUSED BY THE TIM TEST SIGNAL. But the elephant in the room is that in part, TIM tests use ULTRA SOUND to test a SOUND reproduction device. Readers may wonder why this is VALID. And they ask a really good question. Especially since the ultra sound accidently leaking from even cheap CD players and any kind of phonograph cartidges playing vinyl phonograph records is VERY VERY WEAK. FAR too weak to push an amplifier into NON-LINEAR disortion like a TIM test does. In other words, using a limited bandwidth preamp stage only helps solve the problem with TIM tests, NOT problems using real audio signal sources. So no, what fooled many engineers before 1972 is that too often, harmonic distortion tests were most frequently used, AND ADVERTISED, while in most cases testing for INTERMODULATION DISTORTION, a valid IN BAND test, was IGNORED. Yes, the ways in the referenced articles do indeed identify TIM and show valid ways to solve it, but because ultra sound in audio sources is so weak, and TIM tests are so strong in ultra sound, TIM tests therefore uncover a problem that doesn't exist in the real world. Ghidoekjf (talk) 03:58, 8 December 2010 (UTC) Ghidoekjf (talk) 04:22, 8 December 2010 (UTC)

Ah, the shouting! Your rant fails to recognize that TIM test signals are often tailored to the frequency range of the device under test, so that out-of-band audio signals are not introduced. You are getting angry about a problem that is rarely seen at reputable companies. Binksternet (talk) 05:10, 8 December 2010 (UTC)

Oops! (I'm also User Ghidoekjf) I apologize for the upper case. I should have used the bold button. Please consider all the previous upper case to be bold instead. I want it to mean emphasis, not shouting. Actually, I'm not angry. I'm exploring some of the apparently contradictory information from several sources. I would like to see somewhere a TIM test, with tailored frequency content, where the test signal is played off a good CD machine or analog tape recorder, and the spectrum of amplifier input and output is different from each other. Then I'd like to see the intermodulation test of the same amplifier. In any case I think the TIM filter should be flat +/- 1 dB to 22 kHz, and down at least 20 dB at 25 kHz. That's were I'd like to compare intermodulation tests with that kind of TIM test. I'm still looking for one that shows a meaningful difference. Know of one?

Ohgddfp (talk) 14:59, 28 November 2013 (UTC)

Image

Studio Heavy Duty power amplifier, ExpoMusic 2010.

This was added to Amplifier article. I think it is more appropriate here but I didn't want to try and jam it in. --Kvng (talk) 15:06, 3 January 2011 (UTC)

It's not a great photo, with so much busy background and a too-great emphasis on the rolling rack which supports the amplifier. Also, it is obviously an amplifier opened up for display rather than one which is ready to work, or one that is working. If an image of a display amplifier is indicated, the photo should focus more clearly on the subject matter, so that the reader can see what's inside. This image fails in its task. Binksternet (talk) 16:07, 3 January 2011 (UTC)

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Electric instrument amps should be a whole separate subject.

Early in this page, it talks about the "warmth" of the sound of electric instrument amps and, about transistors vs. tubes.

Electric instrument amps are designed to distort the signal. And, when musicians talk about the "warm" character of tube amps, they are talking about the difference between the distortion caused by over-driving a tube stage vs. the distortion caused by over-driving a transistor stage. Such talk should be well segregated from talk about amplifiers that are designed to faithfully reproduce an input signal. 173.75.55.14 (talk) 21:05, 30 October 2017 (UTC)

power amp for guitar pickup signal.

The beginning of the article states power amps are intended to take a guitar pickup signal, among others. Then in the next paragraph it mentions pre-amplification occurs before power amplification of such signals as guitar pickup signals. The example of guitar pickup output should be removed from the list of example signals that may be fed (it is implied directly) into a power amplifier — Preceding unsigned comment added by 68.38.218.65 (talk) 00:33, 1 August 2022 (UTC)