Talk:Valve audio amplifier/Archive 3

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It appears that text which Light current does not agree with or which does not support his POV will be swept away into an archive. My conclusion is that there isnt much point is wasting large amounts of time responding to him in these pages, if he isnt interested that they should be read. He has from many montsh ago an open invitatioon to discuss matters he wishes to keep private by personal email, and I suggest that would be a preverable medium for the sort of discussions that have gone ontubenutdave 22:06, 7 January 2007 (UTC)

I have archived the previous page as it exceeded the recommended limit for any page. Thats all Not trying to hide anything. If you wish to bring up any subject that has been archived, you can copy the relevant parts back here so we can discuss them . But please dont copy big chunks, as it will only fill up the page again.!--Light current 22:12, 7 January 2007 (UTC)

i just came to this article...

... i can't figure out what specifically the disputed statements are, either in the article or outside. care to fill me in with one or two? BTW, the admins have noticed the fracas. r b-j 04:28, 8 January 2007 (UTC)

Well that's the problem: No one (apart from Tubenut) knows what the problem is (and hes stormed off in disgust!) You could look in the archives to get a flavour 8-?--Light current 04:33, 8 January 2007 (UTC)
No, dthe ifficulty following the debate is simply because Lightcurrent re-arranged the discussion pages and even my own user talk page to the point that all coherence has been removed from the discussion - ondeed thats (just) one of the complaints.
For "flavour", the issues that have been under debate include
  • Lightcurrents editting policy which seems to be to remove anything that does not happen to fit with his apparently strongly held "opinions" on this subject (although he admits to having not heard a tube amp - of any type - for a long time, and a number of basic errors and questions in his text suggests that this is a subject he in not an expert in). As many engineering disciplines, Audio engineering is full of many deep subtleties (not least distortion mechanisms and the relationship between subjective sound quality and ,measured performance data). Its imho a big problem to have someone not deeply immersed in the subject making repeated unilateral decisions to remove large amount of text simply because he does not appreciate its significance
  • That he seems to have set his personal opinion about what should be placed on which of these pages above the opinions of all others, specifically his unilateral decision to try to marginalise taxt about audio amplifiers (the dominant application for tubes of the lifetime of the technology) from its original home at "valve amplifiers", since he apparently does not consider audio amplification as a "serious" application (his word .. I question his neutrality ?) .. One wonders why he is so driven to dominate a page on a subject he doesnt really care about..
  • his repeated suggestions that a tube amp is inherently inferior to a transitor amplifier in all respects and is therefore pointless / obsolete (eg suggesting that a transistr amp could if desired be made to reproduce the distortion of a tube amp if that was desired. While indeed this can be done to some degree with eg guitar effects boxes, its manifestly meaningless in the case of circuits whee the tube amp measures as well as sounts duperior to the transistor version .. you cnat make a silk purse from a sows ear, to coin a phrase) .. and for the record Im not biased PRO tubes here ... I have actually built and use both, imho they each have advantages (in different area's). Regardless, the fact remains there are MANY audiophiles that are fanatical about tube amplifiers, and that imho merits a page discussing them. This is not the place for Lightcurrent to endlessly push his (demonstrably uninformed) personal prejudice against them imho
  • His repeated confusion (I am unclear if in writing or understanding) about the relationship between but also independence of concepts such as SE vs PP, Class A vs AB1, NFB vs no NFB. Which imho resulted in text that could substantial mislead a reader of the wikipedia - exactly the sort of "non encyclopaedic" writing he himself rails against. Indeed much of what he seems to consider characteristics of tube amplifiers are actually characteristics of certain types of circuit topology, and can equally be fabricated using transistors.
  • his apparent confusion about the significance of the devaiations of real world transformers and capacitors from the idea, and his ignorance of the subtleties of group delay / phase lag in feedback loops, his seeming unawareness of the limitations of NFB that cant be unbundled from NFBs advantages, all coming together in imho an oversimplistic understandng of what good amplifier design entails (NB regardless of if tube or transistor based)
  • His apparent belief that since "perfection" is impossible, an audiophiles desire to try to approach perfection as closely as possible is somehow misguided. Im quite willing to accept that many people, perhaps including Lightcurrent, cannot appreciate the sonic improvment of a top grade audiophile system cf eg a , and enjoy and appreciate teh experience. And there is a great deal of technical understanding that has gone in to construction these things over the years. Its a matter of fact that many audiophiles (people who do care about sonic excellence and who are often very knowledgable on the technology options to reproduce it) feel that tube amps have sonic advantages. Who is he to say they are all misguided ? He who hasnt even heard such a system <at least for many years> ?
  • an ignorance of, or unwillingness to accept, that this is a field about which very many extremely knowledgable ethusiasts have strongly held (verging on religious) opinions (for example the "superiority" (or otherwise, of the DH-SET ..), imho confusing that there isnt a single consensous opinion about what is "best" with any mention of the issues being just POV or "speculation" and thus removing all discussion about (just as one eg) the distortion spectrums of a SET cf a class AB1 PP, and the sonic consequences of these (which he promptly unilaterally removes .. along the way confusing that eg the monotonically decaying spectrum of a SE stage, or the even order cancellation of an AB1 PP stage, are actually aspects of the circuit topology and NOT of eg a triode as such. (you can make an SE transistor stage if if you wish, or a class A PP stage .. etc .. or even a sans NFB transistor amp !)
imho the result of his disruption is that the page (also the audio amplifier main page) are a pale shadow of what they could and should have been given the time put into this. His effect seems to be to just suck up the time people have to contribute into endless petty arguments... Trolling
His statements regarding himself imho often lack objectivity : for example he often claims his edits are entirely "presentational" in nature (ie typography) so therefore his lack of relevant specialist knowledge isnt an issue, but I have to dispute this : He has repeatedly made large edits removing substantive text on technical matters (that it appears he does not appreciate the significance of), similarly claiming there is no basis for a dispute at all <imho this is abject denial !> // (and on that basis refusing mediation), since he "only" offered guidance on wiki procedures (despite repeatedly being asked to desist) removing large amounts of informative text, and then later complaining that statements have not been justifed (they were, but in text he deleted previously)

tubenutdave 18:02, 23 January 2007 (UTC), completed 24th jan

Or you could look at the RfA wher tubenut appears to have resurfaced. --Light current 15:38, 8 January 2007 (UTC)
Actually No, tubenutdave hasnt "resurfaced" He isnt going to edit th valve amplifer, valve audio amplifier, or any wiki pages further except to occasionally straighten out Lightcurrents propaganda and rewriting of history to show himself in a glorious (if artificial) light, since it seems just a waste of time trying to improve pages Lightcurrent has "camped on", . He seems to have more time to waste on endless wikilawyering etc against anyone with opinions other than his than I (or some other contributors) have time to contribute. As stated - I have given up, out of discust

Lightcurrent can of course be found over very many pages. Objections from other contributors regarding his style and approach are also found over very many pages, the comments from other contributors unhappy with his approach matching my own experiences closely tubenutdave 18:02, 23 January 2007 (UTC)

My editing of this page and other similar ones has been upheld by ArbCom members [1]. I dont really need to say any more--Light current 02:06, 24 January 2007 (UTC)
Actually, no ! here we have an excellent example of Lightcurrents willingness to spin things to a point of imho gross misrepresentation. In the reference he cites the ArbCom members have not said anything at all about his editting of this page or anywhere else, far less supported his approach. The main consensous as I read the ArbComs is that some gentler resolution approach is preferable and should (ideally ?) be tried first, (which I entirely agree with and indeed suggested far back) .... The problem being that Lightcurrent appears to remain in denial about there being any case to answer and on that basis having refused my request for mediation. What can you do ? I cant see any way forward, He continues to unilaterally degrade the page imho, and from experience any attempt to discuss his edits with him is simply a massive waste of time. Tubenutdave 12:16, 24 January 2007 (UTC)
I think the recommendation was to refer our edits for comment (RfC). You are welcome to try that if you wish to. 8-)--Light current 23:20, 24 January 2007 (UTC)

XS removed from page (audiophile propaganda)

--Light current 00:02, 24 January 2007 (UTC)

===Filters===

Historically, the majority of commercial audio preamplifiers made during the "golden age" have complex filter circuits for equalization and tone adjustment, due to the far from ideal quality of recordings, playback technology, and speakers of the day.

Using today's high quality (often digital) source material and speakers etc, such filter circuits are usually not needed. Capacitors (widely used in filter circuits) are far from ideal components and audiophiles generally agree that filter circuits are to be avoided wherever possible. Todays audiophile amplifiers never have tone controls or filters. Since modern digital devices, including CD and DVD players, radio receivers and tape decks already provide a "flat" signal at line level, today the preamp is not needed other than as volume control. One alternative to a separate preamp is to simply use passive volume and switching controls, sometimes integrated into a power amp to form an "integrated" amplifier

The exception remains the phono (vinyl record) pre-amplifiers. Phono pickups provide such a weak signal that preamps are necessary. The poor noise margin of the vinyl record has also resulted in the use of "equalization", where the treble and bass are recorded with different gains. It is therefore necessary to both boost and also correct this frequency response ("equalize") of a phono signal prior to feeding into the rest of the (flat) replay chain. In recent times the RIAA equalization has been standardized, but 78's and other earlier records used a large number of other equalizations (including unintentional frequency response errors due to equipment limitations etc), which presents specialist problems to enthusiasts trying to replay such old records.

This unilateral removal by Lightcurrent is imho a very good example of his imho uninformed, regressive and biased approach.
  • In the edit summery he tries to justify removing text about filters since they do not relate to amplifiers as such. However this misses a number a fundamental points : (a) historic audio source material was often of such poor / variable quality (frequency response errors of > 10dB for example, very high levels of noise and distortion in the HF band etc) that extensive filtering was needed to improve subjective quality. (b) the essential need to equalise (ie filter) material stored on eg records or tapes (c) active fiilters by definition are inseparable from amplifiers/ To suggest that this has no place in an article devoted to valve AUDIO amplifiers is comparable to saying that wheels and engines should not be referred to in an article about cars since they are not specific to cars/ This is verges on reduction to absurdity imho/ Since Lightcurrent demands citations, one good place would be to look at the marketting materials for the QUAD family of preamplifiers during the 1960's through 70's, which expain in great detail why not only filters are needed but why such complex and flexible filter circuits are needed
  • I struggle to see any basis at all for his accusation the text is "propaganda",. Please justify such a loaded statement ?
  • Indeed actually there is nothing in this text that is remotely to do with "audiophile" either. The need for for extensive filtering was generic and found in virtually all audio systems prior to the modern age, eg the RIAA and other phono equalisations, the CCIR and other tape equalisations, dolby NR/ If anything "audiophile" went furthest out of its way to minimise filtering (Hi end was the first segment of hi-fi to abandon tone controls, using reel to reel tape decks with good enough S?N performance to allow recording ''without eg dolby or dBx NR compression (to avoid the undesired sideeffects of that) etc
Indeed, one might infer from his suggestion this is "audiophile propaganda" (?!), as well as diverse other comments of his, that he is in some sense an "audio hater", ... which imho questions why he seeks to dominate the editorial approach to this page so strongly. : "audiophile" is not mentioned even once in the text he objects to. What actually is he objecting to here that he uses terms such as "audiophile propaganda" ?! Lightcurrent, please make a coherent and compelling case justifying your claim this is audiophile propaganda ... or revert your gratuitously destructive edit ?
BTW the shift away from low level preamps with equalisation is significant in terms of the historic development of and the market for such amplifiers, and thus worthy of comment from a historical perspective .. by analogy, in the way that European family cars substantively changed from being 4 door RWD saloons to being 3 or 5 door FWD hatchbacks over a decade or so around the 1980's. (or the current enthusiasm for 4x4's and the problems increasing numbers of those are now generating) This is a matter of historical record and a quick glance at the product catalogs of a cross section of tube amp vendors over the years will clearly show this trend.
tube preamplifers were a major product category, millions having been sold over many decades. They remain of historical interest even if of only limited current application (although some disc'ophiles (?!) are also tube preamplifer enthusiasts, so dont write it off just yet.
I also continue to be shocked by Lightcurrents blatent double standards, ie his willingness to discard any reference to audio preamps - a MAJOR atecory of valve AUDIO amplifiers, maybe almost half of all of them ?! - yet insist on retaining a reference to tube vibration table amplifiers on the main valve amplifier page when there is no significance to this (always extremely obscure) application whatsoever, at all except in the narrowest sense that such amplifiers were made from tubes prior to transistors of the required power ratings being available - which today they are. Hardly objective and balanced inho ... Tubenutdave 12:08, 18:00, 24;00 .. 24 January 2007 (UTC)
I believe mine is the balanced view. If there are others with your views, I am prepared to listen to them.--Light current 23:23, 24 January 2007 (UTC)
That "you believe" is apparent, but has not been supported by any arguments at all. I (at least) believe you view is NOT balanced, for reasons I have outlined in detail. Argue your case, if you can !
What does "others .. I am prepared to listen" mean, you arent prepared to consider my view ? what makes your view more authorative than mine ? Seems to me a lack of respect and/or personal grudge is driving this if you cant present a coherent argument to defend you edit. If you explain your positon then "others" can see it and decide. But so far your position - as so often before - seems to be only tht "Lightcurrent has spoken" (all hail ?).
while we are on the subject I would add some more detail to the discussion about this specific edit.
  • Many of the most common filters used in audio (eg baxandall type tone controls, RIAA equalisation) can provide apparent "boost" of 12 dB or more, but this is of course accomplished in even a passive implementtion out of an insertion loss of even more dB. This gain invariably needs to be replaced (ie amplifiaction).
  • passive filters also typically have a high Z out and require an amplifier as an outbup buffer at the least even if not for input bufering or gain reasons. Its my view that there is a strong case for not only mentioning audio filtering but to actually expand on this considerably (eg baxandall amd opther tone controls, rumble and scratch filters, RIAA NAB CCIR equalisation ..


  • truely standalone passive filters are very rare, aside from the insertion loss but because cables to connect onwards themselves load the signal without some form of impedace buffering. and this is the reaosn audio filters are almost always built as part of amplifiers (prea,ps, integrated amps, or etc)
BTW, try to cut down on the personal attacks would you please. And limit your comments to the article text. Thanks. See WP:NPA--Light current 23:29, 24 January 2007 (UTC)
The comments are entirely on the subject, and/or what you personally have done to the text (including in the wider context of removing gross sections of text from one article and moving it to another). The discussion page is the legitimate place to argue against edits you hve made which I consider to be misguided. I of course have no problems with minor edits to improve eg speeling grammar or phrading but eg the example above where you remove en mass a large section of text without any clear rational, it seems to me reasonable that if there are strong counter argumenst for such an edit you should be prepared to present a coherent and compelling case.
If you argue the case, we can discuss teh subject matter. If you prefer to stand on just holding your personal opinion as the most important one and not even attempt to answer any subject related arguments to the contrary, you have to accept that will be seen as a personal act. I have nothing against you as an individual, I have no clue who you are even. I have very serious issues with the approach you take to editting these pages, which in my view is regressive, for reasons I have clearly explained. And the general problem I have had is that there is never time to work on improving the article itself which i think should be the objective ?) because its endlessly necessry to put in hours going over everything detail by detail (as above where I have outrlines at least 6 technical issues as to why equalisation and filtering is an important part of audio amplifiaction, especially historically (prior to line level sources) to try to explain it to you - when you seem uninterested in the facts, only that your view prevails, (but without any justification for why).
This is the discussion page for valveaudio amplification. discuss and justify WHY you feel some major change should be made here, for example why eg audio filtering should not be presented in this main article here. If you do that we may make progress. If you cannot make a compelling argument for why this should be removed, since imho there are compellingreasons why this shouldab addressed - reasons I HAVE stated - then please leave the text in ! Since others, not leats whoever wrote it originally, presumably DOES feel tehre is a good reason for it to be there. You are not superior, show more respect for others, especially as you have admitted this is not a subject that you are an expert inTubenutdave 10:38, 25 January 2007 (UTC)
Please try to remain civil your postings and address the content, not the contributors, see WP:CIV. Also this is not a place to vent personal feelings about other editors views.--Light current 16:44, 25 January 2007 (UTC)
Your vision seems remarkably selective, and your memory seems defective. Simply restating an irrelevant position ovber and over ( a position you have previously been requested to desist from) is not a "discussion" (its not even a pythionesque argument). its just mindless
There are vast tracts of text above devoted to the content of this article - and despite you being specifically requested to, once more you decline to put forward a single word in defence of the edits you have made - which are presumably based on your views - that others consider to be vandalism. You repeatedly decline to offer a single word either in defence of your own position, countering the arguments presented in a civil way. if you cannot defend your position in an intelligent and reasoned manner, it seems reasonable to assume your edits should be removed, and your objection to doing so is based only upon your own ego, or ?
NB. It could equally well be considered that your comment above (which says nothing more than your previous comment - which was answered above) is addressing me as a contributor rather than the content of this article, so is actually contrary to your own admonisment. The word for which is I believe hypocracy.
This page is for discussion of the article. I have presented a long list of salient points in the text above. . Please stop pretending to be such a sensitive violet (the abuse you have dished out to me and many other wiki contributors is on record), "wikilawyering" by needlessly citing guidelines without justification and that you yourself dont follow. PRESENT A REASONED AND CLEARLY ARGUED DEFENSE OF YOUR CASE FOR THE EDITS YOU HAVE MADE ... or if you arent willing to participate in a discussion of the SUBJECT MATTER .... please stop trolling, just go away and stop wasting everyone elses time ? Thankyou. Tubenutdave 16:11, 27 January 2007 (UTC)
If you could take one bit at a time, we might be able to discuss it.--Light current 02:57, 30 January 2007 (UTC)
I have taken much time explaining things to you already. your replies are consistently without any meaningful comment on the subject whatsoever. seems you are just trolling and trying to waste my time. write something meaningful - or go away please, leaving these pages to people that know and care about the subject Tubenutdave 16:22, 27 January 2007 (UTC)
OK if you are not willing to discuss the finer pints of my edits, I cant force you. But Im asking you for the last time to pleas keep a civil tongue. Thanks.--Light current 10:43, 30 January 2007 (UTC)
for the record, the person consistently refusing to discuss the subject in you. As the history of your entries here clearly shows. I have devoted hours and pages to trying to pursuade. You have not made a single cogent comment related to the subject. You suggesting that I am the one not willing to discuss things in good face is simply another example of your willingness to twist reality beyond any reasonable limits. It seems not possible to discuss anything with you since you appear to not be acting in good faith,simply trolling. And thats perfectly civil language.Tubenutdave 20:22, 31 January 2007 (UTC)

I'm not an expert on audio tube amps. But, from reading the above, I don't see where a good explanation was given for the removal of this chunk of content. If people think it should be put back in, IMO this is a reasonable thing to do until such a time as someone gives a good reason for it not being there. Also, things are getting needlessly personal above- let's focus on the article content, not our perceived problems with other editors. Editor conduct issues should generally be brought up on a user talk page, not an article talk page. Friday (talk) 21:00, 31 January 2007 (UTC)

the chunk of material is not peculiar to valve amps. it applies to all audio amps. i think youll find it has been inserted into audio amplifier article, just under my nice pic of an audio amp--Light current 21:55, 31 January 2007 (UTC)
There is an angoing argument here about (amoung other things) Lightcurrents unlaterally applied idea to fragment this subject totally (see also below where he now proposes removing all references to valve preamplifiers entirely, in the same way he created this page my removing audio from the main page about valve amplifiers (since he unilaterally considers it isnt a "serious") application ...).
I believe this is a fundamentally misguided approach, since it (a) removes all sense of context (b) makes it impossible to find anything on the one hand (c) introduces a need for massive dupication on the other, and/or Lightcurrent then removes critical information further up the self'introduced tree because he considers it "generic" - leaving a reader of the low level article without all the information needed to understand the point being made. Consider an analogy- imagine we wished to discuss the risk of hip fractures in old people - a serious problem that kills many people. Lightcurrents approach would be to argue that all references to fractures should be in an article about bones (since thats specialised) and thereby object to (and uwill nilaterally simply remove entirely) all references to fracture in a page about aging on the basis that this is dealt with elsewhere. The end result is that a reader using wikipedia will never find the information. He will then typically edit the discussion pages to remove and justifications for keeping the issues together.?.
BTW. There are specific technical issues that differeciate a valve audio preamp from a generic discussion of filters (his previous idea) power amps (his current idea) and from preamps built using other gain devices (eg op-amps). Trying to introduce a discussion about the differences between a tube preamp and an op amp preamp on THAT page simple puts us back where we were some years ago when the valve amplifier page was originally created to put in one place the differences between valve amps and transstor (etc) amps.
Its my view that Lightcurrents real objective here is simply to fragment this subject to the point that it gets lost in the dust, since its clear from his comments he doesnt like vavle amplifiers used for audio. Its aleady a problem due to his separation of valve audio amps from valve amps. Dont make this fragmentation any worse Tubenutdave 09:22, 31 January 2007 (UTC)

Previous offers of discussion

for the record: whats this?

If you could take one bit at a time, we might be able to discuss it.--Light current 02:57, 30 January 2007 (UTC)--Light current 20:08, 31 January 2007 (UTC)

for the record, how about simply answering the many reasons given in my original answer (obligingly presented in a list), rather than just saying "do it again". imho thats not a genuine offer to discuss, thats just being irritating.

then of course there were these offers:

Please show me the :huge amount of text that was relevant and informative and replaced it with text that was often technically imprecise, recycling misconceptions, or making statements that may be true in some cases in a form that make them seem to be universal truths,So we can discuss it at length. 8-)--Light current 01:05, 6 January 2007 (UTC)

Please quote : text that addresses matters you hadnt considered to be relevant to amplifiers due to your limited awareness of this subject So we can discuss. --Light current 01:07, 6 January 2007 (UTC)--Light current 20:11, 31 January 2007 (UTC)

Note that pattern here - that as with the "one bit at a time" request .. always you consider the onus is on me to spend yet more time explaining things to you, citing things for you, that has already been covered at length but which you are to lazy to reply to ? ... or you would like them laid out in a slightly differnet format please ? a different font maybe ?. You are well aware of the issues I refer to and will find all the above in the logs.
Stop trolling and give technical arguments for the edits you propose. Meet the specific technical complaints which have been levelled at your edits. Otherwise please go away, you are just wasting everyones time, specifically wasting far too much of my time. Arguing with you has already cost these pages enough hours to have made them really good. You are just hurting the wikipedia, imho seemingly deliberately Tubenutdave 20:22, 30 January 2007 (UTC)
you say:
Meet the specific technical complaints which have been levelled at your edits.
The only person complaining about the articles is you. What are your specific complaints -- one at a time?
If you feel your time is being wasted, thats too bad. But if you do not have the patience to explain your arguments clearly and politely, then its better that you stay away rather than continue in personal attacks that delay progress..--Light current 10:23, 1 February 2007 (UTC)

Standing bias in SETs

One reason for SET's being (usually) limited to low power is the extreme difficulty (and consequent expense) of fabricating an output transformer that can handle the standing bias current in addition to the music signal, without saturating, while avoiding excessively large capacitive parasitics.

Has no one thought of offsetting the core flux by a separate dc winding?--Light current 17:23, 25 January 2007 (UTC)

Unbelieveable. Do you think everyone else is stupid ?. Yes, this idea is probably about 70 years old.
Actually there are several approaches to this problem, each of which has its own advantages and disadvantages. The two main ones are
  • parafeed. <look it up yourself>
  • push pull. (the circuit your propose is effectively "half push pull" - its a push pull output stage where the second tube is just replaced with a load resistor (or some other CCS), thereby halving the efficiency relative to the baseline SET circuit. Adding teh second tube (driven antiphase) doubles teh power as well as cancelling teh even order products
Such a "half push - pull" (SE - idle" ?) looses the simplicity and very low parts count of the SE without the distortion cancellation and efficiency of a true PP either. The OPT utilisation is also very low, so the OPT is still quite large in respect to its output power (compared to a true PP of similar power). This solution thus mainly combines the worst of all approaches for only a modest gain than a true PP OPT does even better. I have heard of exceptional (in the sense unusual, not necessarily good) designs that use the heater/filiament current through a special (and not equal to the primary) winding for partial or total bias cancellation, but this was with exceptional tubes (eg GU81)
As a sidebar (and here we get into more contravercial waters again), some argue that the standing bias in the OPT is actually a good thing sonically, since it puts the music ona differnet part iof the B-H curve. Im not even going to start discussing if thats true or not - the fact remains that some SE enthusiasts believe it, and the continues role of the SET as a power amp is driven by the belief its enthusiasts have in its sonic superiority - for a huge catalog of reasons (which reasons are real or which less significant / imagined is maybe than that it does have a certain (and very appealing) sound when you listen to it ?) Tubenutdave 16:22, 27 January 2007 (UTC)


No Problem in article, problem with Lightcurrents understanding

NB .. what follows is really just an extension of the above SE bias issue, which lightcurrent failed to indent one of his replies to, and then subsequently introduced a seubhead (imho inapproriately) so that the child discussion lost its context.Tubenutdave 20:22, 30 January 2007 (UTC)


So why does article say: extreme difficulty (and consequent expense) of fabricating an output transformer that can handle the standing bias current --Light current 02:47, 30 January 2007 (UTC)

what ?! .. it says its extremely difficult because its is EXTREMELY DIFFICULT. exactly that. Good audio output transformers are works of art, and this is reflected in the very high price. NB this applies to PP OPTs as well as SE OPTs. And even at thaat price they remain engineering compromises. And eg metglass core versions that some say sound best are even less tolerant of bias currents
It becomes increasingly clear that you know very little about valve amplifiers. The purpose of the wikipedia project is to produce main articles to inform everyone interested in a subject. You have removed a great deal of relevant information from the main pages. please stop vandalising pages on a subject you demonstrably are not an expert in Tubenutdave 10:07, 3ó January 2007 (UTC)
But above you said my idea was easy and had been done! so the need for trans with large dc disappears?--Light current 10:52, 30 January 2007 (UTC)
So. despite being obvious and easy, with seemingly very attractive advantages, it remains almost never used. Do you think there just may be some good reasons for that ? Do you think ? Just maybe the rest of the worlds engineers are not totally dumb ?
That it is done very very exceptionally doesnt say anything - there are some people who do thier own fillings and there are some people who set themselves on fire. its easy to get petrol and matches. Doesnt mean its a smart idea.
that you dont appreciate the disadvantages of those approaches simply puts a flouroscene green marker pen line around your ignorance about this subject. Maybe you should master the subject and its mainstream techniques before you pronounce on what everyone else has been doing wrong for the last 80 years ?, and in the meantime stop vandalising these pages by repeatedly removing large amounts of text from it, that you in your high and mighty self importance consider to be not relevant - because the reasons it IS relevant are reasons you are ignorant about?.Tubenutdave 20:22, 30 January 2007 (UTC)
OK if you know the answers, Why is it not done?--Light current 20:00, 31 January 2007 (UTC)
I refer you to the answers ORIGINALLY GIVEN (in the baising SE section above)- that you lost track of maybe after you put in the inappropiate new subhead - you see how fragmentation does so much damage by loosing context?. Since its to much to hope youw will simply refer back .. in short because
  • avoiding the bias current by using eg parafeed places a large capacitor in the audio signal path, and capacitors are even more problematic than transformers if we aspire to any kind of audiophile sound quality,
  • if we shall cancel the flux using a second primary, we waste power and money using onlzy one of those primaries for the signal, its better to add a second drive antiphase .. which is called Push pull. Which also cancels even order harmonic products, which reduced overall measured THD but somewould argue the residual distortion is of a less acceptable nature
Almost all audio amps are either SE or full PP, your half PP idea has the disadvantages of both, throwing in even lower efficiency than either for good measure. OK now ? Wasted even more time ??. Tubenutdave 09:22, 31 January 2007 (UTC)
So its NOT extremely difficult to fabricate a transformer circuit to offset the effects of core saturation, just undesirable? If so this is what the artilce should say.--Light current 10:17, 1 February 2007 (UTC)
What was originally written was that making an audio (output) TRANSFORMER (with good performance, eg wide bandwidth, flat response, low parasitics and leakage etc) is very difficult. And this is unconditionally true, regardless of the flux the core is specified to carry. And this is worth saying, its a central and critical component in any mainstream audio power amp. OTLs avoid transformers, but at the expense of many other problems instead, problems that have generally consigned the OTL to the fringes. eg parafeed changes the design compromises, but is again a fringe approach with its own problems, and it does not eradiacte the design difficulties or production costs of the output transformer that is still needed, even if it does change the specification somewhat
NB that even a PP transformer than has no "bias" flux still has to cope with flux when there is a signall going through it, by definition. and in reality even PP transformers are usually gapped to better withstand at least some DC bias due to imbalances.tubenutdave 21:30, 2 February 2007 (UTC)

Title of page

I propose a note at the top saying this page deals with power amps only. Audio Preamplifiers are dealt with elsewhere--Light current 20:06, 31 January 2007 (UTC)

I'm really only familiar with tube amps in the context of guitars- however I note that this article mentions this application as well as more general-purpose amps. So, I don't see why you'd say this article is about power amps only. This article is about tube audio amps in general. Friday (talk) 20:30, 31 January 2007 (UTC)
Because i would like to keep the subject of tone controls and all its attendant hoo ha regarding audiophile pros cons etc., out of this page and put it in the preamp page. This page mainly talks about valves as power amp devices anyway. I would like to keep it like that.--Light current 21:30, 31 January 2007 (UTC)
Well, common people use the word "amp" differently than an electrical engineer uses it, right? To the engineer, an amp might be a type of circuit, but to the average person, an amp is a box with knobs on it that's part of their stereo. The average person's box they call an "amp" often contains both a pre-amp and a power amp, and it often has controls other than just volume. I understand that technically, a pre-amp and a power amp are quite different things, but so far this article seems to be about both of them. Friday (talk) 21:39, 31 January 2007 (UTC)
please look around the related articles on amplfiers, so you can see the emerging problems 8_(--Light current 21:48, 31 January 2007 (UTC)
Hello Friday, welcome to this world of endless arguments with Lightcurrent ! ...
The viewpoint you outline above is one I find very straightforward and compelling. As noted elsewhere I also believe we should not fragment further. As you say, this page is about valve audio amplifiers - collectively.I think many of the "problems" in other amplifier pages are themselves due to excessive fragmentation previously. As well also making the information accessible to a reader wanting to learn about the subject in context, as you indicate.Tubenutdave 10:00, 31 January 2007 (UTC)
Howdy, and thanks for the feedback. The endless arguments are part of what I'm hoping I can help out with. If there needs to be a requests for comments on this article, we can do that, but I don't know for sure that it's necessary yet. I made the suggestion below that we focus entirely on the article itself in hopes of not getting off track in unproductive debates. I'm not trying to point fingers and suggest that any of this is anyone's fault, mind- it's very easy to get sucked into off-topic conversion, I've done it many times. I won't understand the engineering details, but I can give you a layman's perspective on things. If part of the problem is how to organize various related articles, I can give you opinions on that without needing to understand techie details. I'd like to invite everyone involved here to take a fresh start on things, and do your best to forget past disagreements or difficulties. Friday (talk) 01:49, 2 February 2007 (UTC)
Im not going to discuss this with two editors who know nothing about electronics or haw to edit WP in general. So its over to you 2--Light current 02:18, 2 February 2007 (UTC)
Let me know when youve finished and I might come back to try to clear up the mess!--Light current 02:21, 2 February 2007 (UTC)
Wow ?!?!
Firstly I'd like to say I completely support Fridays suggestion to have a fresh start. (I made a similar proposal previously). Anyone else reading but having so far stayed out of the argument (perhaps well judged) is also most welcome too ...
Also if I understand Light currents response above he will stay out for a while until to allow us time to get things in a form we think is promising, is that correct / a promise ? I would request you stay away from
  • valve amplifier
  • valve audio amplifier
  • valve sound
we let you know when our efforts are ready for your inspection ;-)
however, as a closing comment to Light current, in line with your own repeated request for civility, please to not insult the abilities other people you dont know. It is my understanding that several people who have contributed to these pages are professionally qualified electrical engineers or similar. I am professionally a microwave radio systems designer, and have been designing valve audio amplifiers very successfully for some years. Whereas it is clear from your own postings that your knowledge of this field at least is quite limited. Please have greater respect for others & their opinions.tubenutdave 21:17, 2 February 2007 (UTC)


A suggestion

Having looked at a bit more of the exchanges here, I have a suggestion. Use the talk page for discussing the article only- do not discuss the subject matter here except as needed to improve the article. So, Light current, if you have a "have they tried doing this?" question, don't post it here. Tubenutdave, don't respond to questions except as needed to improve the article. This isn't the place to try to come up with ideas for tube amps. I strongly suspect the experts in the field have tried whatever ideas some Wikipedia editor can come up with. Friday (talk) 17:44, 1 February 2007 (UTC)

The Qs I put are to do with the subject matter of the page. At least I try to make them so. You must decide for yourself whether Tubenut is using this talk page properly.--Light current 18:41, 1 February 2007 (UTC)
Right, what I'm suggesting is that the talk page is for talking about the article, not the subject matter. Go find a forum if you want to kick around ideas on circuit design, or debate the merits of tube amplification. This isn't a general "let's chat about tube amps" area, this is the talk page for an encyclopedia article. Friday (talk) 19:33, 1 February 2007 (UTC)
Are you accusing me of chatting about tube amps? And how exactly is the subject matter of the article differentiated from the contents of the article would you say?--Light current 00:39, 2 February 2007 (UTC)

I'm not accusing anyone, I just think the discussion has gotten off track a bit here and there. There's no point spending time on discussion that's not relevant to improving the article. Friday (talk) 01:30, 2 February 2007 (UTC)

And how exactly is the subject matter of the article differentiated from the contents of the article would you say?---Light current 02:16, 2 February 2007 (UTC)
we dont rise to this furthertubenutdave 22:02, 2 February 2007 (UTC)

New structure proposals

As obove I welcome and strongly support Fridays proposal . I suggest and actively seek a short discussion as to how to do this taking in views from as many as are interested - lets figure out our direction before we start work power editting ;-)

Purely to start the ball rolling I would propose something like..

Scope : this article will primarily address amplifiers for REPRODUCTION of music, ie domestic Hifi's, and PERFORMANCE of music (notably guitar amplifiers (accoustic and electric) and to a lesser degree PA. It will not primarily address the use of valve amplifiers for as AF amplifiers in telephony applications, radio receivers, those systems have very different objectives and AF amplification is only an ancilliary subsystem within the overall application

Structure

Types : I propose the discussion about the "sound" of SE vs PP, NFB etc from the article "valve sound" be moved here in cleaned up and cut down / more accessible form to explain the differences and relative advantages . disadvantages, sonically and technically
Historic amplifers, lets arbitrarily define that as up to the point the transistor became a commercial alternative (the fifties) ? (mainly SE)
Classic "golden age", (maily PP, post williamson) power amplifiers (quad, Dynaco, Macintosh etc), often based on the last generation of indirectly heated double triodes 6AX7 / ECC 83 et al) and power pentodes (EL84/ 34 / KT66 / 88 etc
Modern "audiophile" (power) amplifiers, specifically the SE (notably the DH-SET) the PP, and the OTL
Guitar amplifiers etc
Technology ... the main valve AF circuit stage topologies (on a "for dummies" level) .. the SE gain stage, the diff long tail pair, the SE and PP output stage, the phase splitter
historic valve preamplification, includimg microphone amplifiers, phono equalisers and amplifiers, tone controls & scratch / rumble filters, historic phono equalisations (ie other than RIAA)
modern valve preamplification (short)

The valve sound page should then be deleted imho, or at best replaced with just a stub noting that there is such a thing as "valve sound", but noting it is as much to do with circuit designs as valves per se (hence how it is possible to make transistor circuits that try to emulate - albeit with reduced performance - the sound of tube stages, not least in guitar effects boxes !, also notin the similarites between triode and mosfet, bipolar transistor and tetrode

But this is just a starting proposal .. please modify / improve / make counter proposals ! tubenutdave 21:17, 2 February 2007 (UTC)

I don't have opinions on a lot of this, but: I agree that valve sound seems a bit redundant with valve audio amplifier. I suppose one could focus on technology and the other could focus on sound, but I'd personally try to keep them together and only consider a split if length becomes an issue. I'd treat pre-amp/power amp issues similiarly- keep them both in one article until it gets too long. Friday (talk) 21:33, 2 February 2007 (UTC)
Many thanks for your comment, seems a good approach to me to. I will also wait say at least 24 hours and see if any others are reading and wish to join in or has additional suggestions ! In particular if anyone is "into" guitar amps, help with that would be most appreciated (I am not "Into" them) ! tubenutdave 22:06, 2 February 2007 (UTC)
Guitar amps are the only reason I'm even aware that people still use tubes. Tube amps are still favored over solid state by a great many guitar players. Friday (talk) 22:15, 2 February 2007 (UTC)
Its also my impression that guitar amps are the only area that tubes remain the dominant mainstream. however tube amps remain (mostly in the heady waters of the high priced so called "high end") of hifi amplification as well. I think this page should perhaps try to reflect this, ie should say more about Guitar amps, in particular respects with which these differ from Hifi amps, help on hat aspect would be most appreciated, I am not a guitarist ! tubenutdave 10:21, 3 February 2007 (UTC)

Guys, I have made a start on our reqwork of this page, please also pitch in.

  • I have initially added a bit of an introduction, and expanded the history section
  • NB there is a stub in the history section for the birth of the elelctric guitar etc .. this was what, les paul ?!?!? .. Please can Friday or some other guitarist adopt and populate this stub especially !

Comments or better yet simply edit in any further improvement idea's you have, very welcome ! tubenutdave 17:09, 4 February 2007 (UTC)


Have tried to gather all the "technical" stuff into one big section - although this now has a lot of duplication as well as generally needs a wholesale cleaning up. I will also move this section to the BOTTOM (below the stuff aimed at more general readership) during my next editting session. but now its time for tea ;-) tubenutdave 17:46, 4 February 2007 (UTC)

archive time ?

If anyone knows how to make an archive, I think it would be good to move on from the large amount of spilt milk thats long under the bridge now and have a clean sheet here as we set out on trying to improve the page ?

I tried, but somehow messed it up, I tried to revert the change to undo it. If anyone has a better idea how this should be done please do ?! .. thanks / tubenutdave 17:12, 4 February 2007 (UTC)

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