Talk:Valve audio amplifier

Untitled
Not to revive the old Aluminum/Aluminium argument here, but it appears to me that only British English speakers refer to vacuum tubes as "valves". This article should be renamed to reflect that. —Preceding unsigned comment added by 96.252.117.34 (talk) 15:33, 13 March 2009 (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. Comments or better yet simply edit in any further improvement idea's you have, very welcome ! tubenutdave 17:09, 4 February 2007 (UTC)
 * 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 !

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)

....... many edits later

Hi all. I am delighted by the way this article has blossomed the last weeks, including attracting additional contributors. Much restructuring has been done but I think in its current form the layout is now quite good, I hope you all agree.

I do not plan any further large edits to this article and I hope that others will continue to refine it. Many thanks all for your efforts tubenutdave 13:12, 17 February 2007 (UTC)

PS NB that Dark Future appears to be a sock puppet for the (currently banned) Light Current

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)
 * I’m no expert on it either, but How to archive a talk page explains it. --Van helsing 12:51, 5 February 2007 (UTC)


 * I see someone has fixed it - whoever it was, many thanks. tubenutdave 13:37, 6 February 2007 (UTC)
 * You're welcome. —The preceding unsigned comment was added by Van helsing (talk • contribs) 15:50, 6 February 2007 (UTC).

Diagrams
Would be nice to have some cct diagrams on this page. Maybe there are some can be imported from other pages? —The preceding unsigned comment was added by SlipperyHippo (talk • contribs) 16:48, 12 February 2007 (UTC).


 * I agree. I have added some generic diagrams (and thgere is a buildable class A PP circuit) but I agree it would be nice to have some "real" ones as well. However I am concerned about IPR, I assume most "classic" designs are covered by copyright. tubenutdave 23:59, 15 February 2007 (UTC)


 * Yes but the diagrams you have drawn yourself are Ok. So any commercial circuits you want to redraw and upload will be free of copyright!--SlipperyHippo 15:47, 16 February 2007 (UTC)


 * Im not sure its that easy ;-) You may be correct regards if its technically copywrite infringement, but it would definitely remain IPR theft imho, .. imho at best its a morally grey area. I think it would be preferable to restrict uploading to circuits that the designer or publisher has placed in the public domain. It may be possible to get permission for the Mullard 5-10 and the Williamson, these circuits are widely published (with permission) in many books, the owners seem happy to allow this. tubenutdave 13:19, 17 February 2007 (UTC)

Spell Checking
I've made a few corrections to obvious typos in this article. The article uses a lot of technical language, so there are lots of words which I've left unchanged. I apologise if I've 'corrected' a technical spelling that didn't need to be corrected. DanBeale 16:47, 3 March 2007 (UTC)

Transconductance characteristic of triode
Im a bit confused. The transconductance (Ia/Vg) characteristic curves of triodes that Ive seen are quite non linear, yet the article says that triodes can be very linear amplifiers Can anyone explain this apparent anomoly? --SlipperyHippo 20:58, 21 March 2007 (UTC)


 * SH, I don't know if you still around but I do believe I have an answer for you. The plate-to-cathode voltage enters into the plate current equation in the same way as the grid-to-cathode voltage does.  Thus, when there is a series resistor in the plate circuit, the voltage across this resistor provides degenerative feedback in exactly the way that a resistor in series with the cathode does.  Thus, a triode connected as a common cathode amplifier is linearized by the degenerative feedback from the voltage across the plate resistor.  Bottom line, the triode is not an inherently linear transconductance amplifier by any stretch.  But, like any non-linear amplifier, it is linearized by degenerative feedback that is, in the case of the triode, somewhat unavoidable when used as a voltage amplifier.  Alfred Centauri 03:57, 14 May 2007 (UTC)

Rephrase== ==

"the Ultra-Linear output stage (a variation of push pull with tetrodes) was originated by Alan Blumlein in 1937 in the UK, but popularised following publication of a paper by David Hafler and Keroes in the USA in 1951, and became the dominant topology during the post war recovery of consumer products"

Most consumer products were single tube class A output. So a different phrasing needed imho. Tabby (talk) 23:14, 13 December 2007 (UTC)

Capacitor quality comment
"capacitor quality (often very poor compared to modern types)"

Where does this idea come from? It really isn't so. You have to go back to the 1920s to find lousy cap quality. 1950s and 40s caps were used in some seriously excellent amplifiers, Leak point one, Quad 2, etc, and sound and cap reliability were both fine. Tabby (talk) 23:14, 13 December 2007 (UTC)

Weasel words
Under the "Valve Sound" section - "..the audiophiles"? We, the audiophiles? They, the audiophiles? This is both very broad and very ambiguous - well, it's weasel words. —Preceding unsigned comment added by 166.70.188.26 (talk) 17:15, 22 April 2008 (UTC)

Cross-Article Issues
This article, in the section "Notable Historic Designs," contains a cross reference to a "main article" Notable historic valve amplifier designs and then presents what is in effect a list of historic designs. The cross reference link, via redirect, takes the reader to an article actually titled List of valve amplifier designs, which is not a list at all but instead contains brief histories of exactly the same amplifiers listed in the present article. The "List" article also contains a cross reference to this article as the "main article." Thus, we have two articles each pointing to the other as the "main" article on its subject, a "substantive" article that contains a bare list, and a "list" that contains substantive text. At the very least, the list section of this article and the text in the other should be flip-flopped, but if all we have for the "list" is the few amplifiers mentioned here, might perhaps a better approach be to merge the two and do away with the "list" entirely? Drhoehl (talk) 01:22, 7 January 2013 (UTC)