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#161
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Miles O'Neal wrote:
On Fri, 27 Feb 2004 18:45:28 +0000, Fred Nachbaur wrote: [very sensible response snipped] It's usually quite obvious from the context whether the "Class A" being referred to is per the original definition, or in the context of a "class AB amplifier operating in the class A region." Well, to you or me. To the average guy who's still trying to figure out what the "Class A' hoopla is, and what it means, and whether he wants it, it just sounds like *all* amps are Class A if you don't play them too loudly, and hence they will all have that magic. Yikes! a class AB amplifier can not operate in the class A region. If it would operate there it would be class A biased A class AB amplifier on low volume amplifies like a class A amplifier with 360° conduction angle, but ist still AB biased and so is operating class AB. The same amplifier high driven amplifies like a class B amplifier and ist still operating AB by its biaspoint. Peter |
#162
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On Fri, 27 Feb 2004 00:21:03 -0500, Rich Koerner wrote:
In fact, there are *no* class B amps. What the hell are you talking about!!!!!!!!!!!!! Maybe he meant in hi fi and guitar amps. Obviously they exist in other worlds, but not in these two, AFAIK. .... A class B amp What the hell are you talking about!!!!!!!!!!!!!!!!!!!! I've wondered a time or two. 8^/ .... Load relationships is not the issue to understanding the class of operation of the tubes. The role of the load is irrelevant!!!!!! You simply don't look to the load to identify the class of operation. Apparently he does. He defines class of operation by load, THD and, as far as I can tell, POTM. 8^) .... Such an amp is regarded as class B. Everyone knows there is bugger all class A power, and lots of class B power. Which I found hysterical. Even translating into his terms, it's just plain silly. I have a 12W Class A amplifier in my shop at the moment. I can easily build a 30W Class A amp from 6L6GCs (know he would claim it was only 24W). But again, I suspect he's refering to hi fi amps, since my 12W and 30W would be at much higher distortion levels than he would be willing to tolerate. [Actual definitions snipped] Now, start from there, and you will have more here in AGA, who have a chance of following you. Or anywhere else there is anyone with much of a EE background. Hey! I think I want to define "mu" as "what the stage circuit gain ought to be". That way I can make all sorts of observations about the fools who run their amps at sub-optimal mu levels. Maybe I'll call that "lu" for "lusers". 8^) BTW, I'm not casting any aspersions on his abilities as an amp tech or designer - hifi or music. And he can be pretty funny when he wants to. Although he didn't go far enough in the bit about the Australian pubs. I think when the celebration gets so intense the pub burns, they consider it cause for an even bigger celebration, and go looking for another pub to "hang" in. -Miles -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#163
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On Tue, 24 Feb 2004 23:34:47 -0800, lbrty4u wrote:
Well, good for PA, or a muso. Not for hi-fi. The thd is too high. WTF is the matter with you? We are talking about guitar amps, hello? Alas, no. The original post was about bass guitar amps, true. But since it was cross-posted to the horribly misnamed rec.audio.tubes [1], the discussion may be about guitar amps, it may be about hi fi amps, it may be about any sort of audio amps, or it may be about theory, or any combination or permutation thereof, with probably a few more categories I haven't thought of at the moment. We of AGA are demanding precision and context from those in RAT (things we can't always manage in AGA alone 8^); let us be precise and contextual when dealing with them as well. And in this case, Patrick provided context. I must say, despite some of the bizarre things I have seen, this thread has been a real treat, with lots of good stuff in amongst the odd. [Not that odd is necessarily bad, but in this case I believe some of it is detrimental to communication, and hence to many reading it.] -Miles [1] At least, in my limited exposure, it seemed it should have been called something else. Perhaps rec.audio.highend.hifi.tubes . 8^) -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#164
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I still haven't seen an answer; perhaps
the question was overlooked, being buried in another post. What is a "cadence" amplifier? -Miles -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#165
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roger wrote: What a ****** you are. Do you ever take your hand off your dick? Rodger, for the man who started a most informative and lively thread, you seem to be the one who learned the least. So, there is some value to trolls. Regards, Rich Koerner, Time Electronics. http://www.timeelect.com Specialists in Live Sound FOH Engineering, Music & Studio Production, Vintage Instruments, and Tube Amplifiers |
#166
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Miles O'Neal wrote: On Fri, 27 Feb 2004 00:21:03 -0500, Rich Koerner wrote: In fact, there are *no* class B amps. What the hell are you talking about!!!!!!!!!!!!! Maybe he meant in hi fi and guitar amps. Obviously they exist in other worlds, but not in these two, AFAIK. I said there were no class B amps. When I said that, I meant there were none used in audio, just as there are no class C amps used in audio. A class B amp has no bias current. the tubes sit there turned off, but on the brink of turning on. Any lower bias voltage applied makes them a class C amp. The crossover Dn is high in such things in audio, so they ain't used. But where the bias current is allowed to be some low amount, the PP amp is imediately a class AB amp, but it behaves with very little class A power, and most is class B. Rich seems unable to make any sense out of this, and I have given up trying yo educate the man into seeing that *all* class AB amps have some small portion of class A power up to a threhhold where tube cut off occurs, and then for the rest of the cycle, its class B, and I don't want another stoopid argument over definitions or class of operation. My server went down for 2 days last week, and I have missed a few posts, but Imdoubt I missed much by the look of it. ... A class B amp What the hell are you talking about!!!!!!!!!!!!!!!!!!!! I've wondered a time or two. 8^/ ... Load relationships is not the issue to understanding the class of operation of the tubes. The role of the load is irrelevant!!!!!! You simply don't look to the load to identify the class of operation. Apparently he does. He defines class of operation by load, THD and, as far as I can tell, POTM. 8^) The operation of the tubes defines what is the class of operation, and the class of op is affected by load. So a class A amp with one value load becomes a class AB amp with a lower value load. Or alternatively, a class AB amp with a specified load will become a class A amp if the load value is raised. ... Such an amp is regarded as class B. Everyone knows there is bugger all class A power, and lots of class B power. Which I found hysterical. Even translating into his terms, it's just plain silly. I have a 12W Class A amplifier in my shop at the moment. I can easily build a 30W Class A amp from 6L6GCs (know he would claim it was only 24W). One could set up any pair of tubes with low bias current to make 30 watts, in an AB situation. The amount of class A power will be quite low. The thd will be quite low for the first 1/2 watt, but then rapidly become quite high, which could be fine for a guitar amp, but not for hi-fi. For hi-fi we'd use higher bias current, and perhaps have 12 watts of class A, after which the limit of 24 watts is reached in class B, and the whole operation from 0.0watts to 24 watts ic called class AB operation. But again, I suspect he's refering to hi fi amps, since my 12W and 30W would be at much higher distortion levels than he would be willing to tolerate. You have not cited working conditions. But 2 x 6L6 can be used in triode to make 12 watts of very low distortion class A, with 12 dB of FB, or 22 watts in tetrode, with 20 dB of FB. (snip) Patrick Turner. |
#167
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On Sun, 29 Feb 2004 13:33:39 +1100, Patrick Turner wrote:
Rich seems unable to make any sense out of this, and I have given up trying yo educate the man Now that's the funniest thing you wrote yet. into seeing that *all* class AB amps have some small portion of class A power up to a threhhold where tube cut off occurs, and then for the rest of the cycle, its class B, and I don't want another stoopid argument over definitions or class of operation. Gotcha. You can redefine anything you like, any way you like, any time you like, and if anyone else disagrees with you, they're stupid. You sound like a borderline sociopath, there, Patrick. You really need to go google for my post that has "Patrick" and either "Patsy" or "Patti" in the subject. because you missed a *lot*. -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#168
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Patrick Turner schrieb:
I said there were no class B amps. When I said that, I meant there were none used in audio, just as there are no class C amps used in audio. class B amps were widely used in public address systems A class B amp has no bias current. the tubes sit there turned off, but on the brink of turning on. class B data for EL34 (by Telefunken): Ub=800V, Ug2=400V, Ug1 -39V Ia idle 2x25mA, Ia driven 2x91mA Output power 100W at K=5% All audio tubes in AM modulators are class B Any lower bias voltage applied makes them a class C amp. class C is deep biased to cutoff example 807 in class B Ug1= 45V, class C -90V The crossover Dn is high in such things in audio, so they ain't used. But where the bias current is allowed to be some low amount, the PP amp is imediately a class AB amp, but it behaves with very little class A power, and most is class B. the EL34 bias for class AB is 2x75mA compared to 2x25mA in class B The operation of the tubes defines what is the class of operation, and the class of op is affected by load. no, by the bias-setting So a class A amp with one value load becomes a class AB amp with a lower value load. no, the class is not changing, only the conduction angle, the class is defined by construction and bias adjustment Or alternatively, a class AB amp with a specified load will become a class A amp if the load value is raised. amplifier classes are defined by static values, not by dynamic Peter |
#169
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Patrick Turner wrote: Miles O'Neal wrote: On Fri, 27 Feb 2004 00:21:03 -0500, Rich Koerner wrote: In fact, there are *no* class B amps. What the hell are you talking about!!!!!!!!!!!!! Maybe he meant in hi fi and guitar amps. Obviously they exist in other worlds, but not in these two, AFAIK. I said there were no class B amps. When I said that, I meant there were none used in audio, just as there are no class C amps used in audio. A class B amp has no bias current. the tubes sit there turned off, but on the brink of turning on. Any lower bias voltage applied makes them a class C amp. The crossover Dn is high in such things in audio, so they ain't used. But where the bias current is allowed to be some low amount, the PP amp is imediately a class AB amp, but it behaves with very little class A power, and most is class B. Rich seems unable to make any sense out of this, and I have given up trying yo educate the man into seeing that *all* class AB amps have some small portion of class A power in summary I knew all along what you were driving at, but by the confusion of others, it was obvious your choice of words and terms weren't working for clear explanation. So far, you're doin better. You didn't add in the %'s with the loads, and all the rest of the stuff comparing it from SE to PP, all in the same breath. You, or someone else had me commenting because of the lack of clarity. I had to point out, 20 volts across nothing, means NOTHING. 20 volts across 4 ohms, means SOMETHING. Clarity is a nice thing, when proper terms are used too. I find it strange that the points of tube "saturation" didn't pop up along the way too. Still, no one said why the "A" portion, though small, has a reason for being there. I thought, that would have entered the dialog at some point. But,...... that's ok. Most have a handle on what's in front of them, and they are doing ok too. So, does it really matter. What really mattered, was that there is simply no comparisons that can be made with the common configured amplifiers of choice from both camps with respect to the 6550 tubes, with their operating environments being worlds apart. There is NO WAY, they can be compared in the same breath. Just sit a 400-PS or SVT next to your current hot dog Hi-fi amp, and there is NO comparison. It's the 400-PS that separates the Tubes, from the Turds!!!!!! I even test out 6L6 class tubes in a 400-PS. Here, take a look, http://timeelect.com/test/turd-tester.jpg Good USA made 6L6-GC's will take the punishment, with a good performance yield. All the time without plates turning color. GE's hold up a lot better than any from off shore. When it comes to putting the squeeze to get the juice out of the tube, I don't play around. You audio guys babied the turds for so long now, you have come to think the GE and the turds are equal, without regard to the differences in the loading windows of the tubes in question. Put the GE's in one of your baby machines, and they will out live the turds. Still, the reference to a 300 watt class A SVT, had me rolling on the floor over here. SO, what does that say about that post then. Regards, Rich Koerner, Time Electronics. http://www.timeelect.com Specialists in Live Sound FOH Engineering, Music & Studio Production, Vintage Instruments, and Tube Amplifiers |
#171
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Miles O'Neal wrote: On Tue, 24 Feb 2004 14:31:12 -0500, James Angelo Ruggieri, P.E. wrote: For many years and many years past - I worked at what used to be Guitar Lab on 48th Street in NYC - and came onboard right after DeMarzio left. I fixed, modified, and designed/built many tube cadence amps So what is this "cadence" amplifier you keep refering to? http://www.ossaudio.com/ Go here and click on cadence on the top of the page. Scroll down to the tube amp. That must be it!!!!!! Regards, Rich Koerner, Time Electronics. http://www.timeelect.com Specialists in Live Sound FOH Engineering, Music & Studio Production, Vintage Instruments, and Tube Amplifiers |
#172
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"Miles O'Neal" wrote:
I still haven't seen an answer; perhaps the question was overlooked, being buried in another post. What is a "cadence" amplifier? Miles, Dood! Search engine seized up on ya? :-) Best I can come up with is that they're car audio amps. I don't recall seeing your original question, so I dunno if there was any context beyond the "what is", but pretty much all of the hits I came up with refer to Cadence Amps or Cadence Mobile Audio. Interestingly enough, the first hit on "Cadence Amps" was this: "Musician's Friend - 1000's of instruments, musical accessories, and more. We'll match any price on Cadence Amps you find - Free Shipping on orders $299 or more." But if you follow the link, you end up at the Musician's Friend search results page with "We are unable to find exact matches for your search". Amusing, if you can describe hoodwinking in that way. :-) Monte |
#173
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Rich Koerner wrote in message ...
BTW, what do ya play, if I may ask. You will be disappointed. :-) After 13 yrs of workingman rock, then 20 more making believe I was Roy Buchannan (which took the first 10 to master on that bitch of a '52 Tele & a dimed VR), and then a 12 yr break & 2 amputated/reattached left fingers, I'm now a fledgling jazzer. I do some acoustic stuff on the side like baroque folk (Renbourne etc.). I have gotten to the point where I like the idea of walking into a gig in one trip with a free hand for the door, and no one to argue with, to tourists who are awed by my feeble, bull**** attempts to play jazz, with and without only a female singer through a tiny, powerful sandbox & complex music. But I still go crank & wail with they boys once in awhile to make sure I can still do it. I was never the best, but guys my age wrote the book on rock ' roll & we ain't dead yet. :-) |
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