I have hundreds of amplifiers, And I actually listen. The el84 is a good tube. Seems Altec thought so too, They went all out when they built their 344a amplifier.
Oh and by the way, Get out much?
Oh and by the way, Get out much?
I think I already addressed the ubiquitous nature of the EL84 more than adequately. Manufacturers are ALWAYS looking at the bottom line. The ones who cared more about quality used better tubes.
I'm sorry you can't recognize when you are wrong or actually counter with facts that are relevant to the discussion. If you love the EL84, rock on, use the EL84. I have proven to my satisfaction that it is inferior. I did so by substituting different tubes in the same circuit as an EL84 and getting better results. The only diff between a 6V6 amp and EL84 amp is the cathode resistor. Anyone can prove to himself (or herself) that the 6V6 sounds better by simple substitution. And, once you have converted to octal, there is nothing stopping you from subbing in the 6P3S and observing that it too sounds better than the EL84.
As I predicted, all sorts of hurt feelings 'cause I revealed the EL84's shortcomings.
in the same vein, auto manufacturers only build a few high quality cars that make up the bulk of their profits. They sell millions of poor quality vehicles with shoddy engines and transmissions, etc., on which they barely turn a profit.
Forgot to include a Qfactor calc. for the GU50:
Using the middle of the gm range given on the datasheet, 4200:
Max gm = 4200* (150/50)^.66666 = 8736
Qfactor = 8736/150 = 58
Putting the GU50 among the best tubes, better than a 300B (Well, by this simple minded gm per current criterion. It also does not appear to have a very fine mesh g1, nor a particularly well aligned g2, so this may be giving somewhat misleading results. )
6LQ6 at 51
Gu50 at 58
6DQ5 at 67
6L6 at 72
6CD6 at 74
300B at 77
GU50 (and Russian tubes in general) seem to have wide variation of parameters as manufactured. Using the upper end of the gm range, from the GU50 datasheet, 5500, sends the Qfactor off to 76, fairly average (average around 80 for most output tubes). So some selecting may be in order.
(A high gm tube, above the bogey spec, possibly has the grid mis-aligned, putting grid wires on one side closer to the cathode than the other side, causing distortion. Or, the coating on the cathode is too thick, causing the grid wires to be closer to the cathode surface.)
Using the middle of the gm range given on the datasheet, 4200:
Max gm = 4200* (150/50)^.66666 = 8736
Qfactor = 8736/150 = 58
Putting the GU50 among the best tubes, better than a 300B (Well, by this simple minded gm per current criterion. It also does not appear to have a very fine mesh g1, nor a particularly well aligned g2, so this may be giving somewhat misleading results. )
6LQ6 at 51
Gu50 at 58
6DQ5 at 67
6L6 at 72
6CD6 at 74
300B at 77
GU50 (and Russian tubes in general) seem to have wide variation of parameters as manufactured. Using the upper end of the gm range, from the GU50 datasheet, 5500, sends the Qfactor off to 76, fairly average (average around 80 for most output tubes). So some selecting may be in order.
(A high gm tube, above the bogey spec, possibly has the grid mis-aligned, putting grid wires on one side closer to the cathode than the other side, causing distortion. Or, the coating on the cathode is too thick, causing the grid wires to be closer to the cathode surface.)
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I built a GU 50 ultralinear amp. was (and still am) really, really happy with the sound quality. And I chuckled when I found a post by someone who stated the Gu50 can't be run in ultralinear. Then I built an ultralinear 6550. Not even close, which frankly shocked me at how much better the GU50 sounds.
Then I recalled that testing proves Pentodes benefit more from ultralinear mode than tetrodes. I think the GU50 is a real "sleeper" tube with a lot of potential.
Re: Russian consistency. I bought a bulk lot of the 6P3S and put 'em on the tester. They were all astonishingly close. the 6P3S-E, not so much. about the variation one would expect. Apparently they were pretty good at making the 6P3S. Wish they had the same consistency with the GU50.
Have you ever dissected a GU50?
Reason I ask is that I cannot see the g1 mesh very well in the (intact) samples I have. The g2 wire mesh is less dense than typical TV sweep tubes, so I am assuming the g1 wire is one to one with that. But being a pentode, it may not have any pitch match at all with the g2, so I could be mis-reading the g1 pitch. Since the g2 current remains fairly low, it does seem to have some alignment though. I only have two tubes, so I am reluctant to break one open to find out. It could also be that the g2 is wound at twice the wire spacing as the g1, which would give some alignment effects.
Reason I ask is that I cannot see the g1 mesh very well in the (intact) samples I have. The g2 wire mesh is less dense than typical TV sweep tubes, so I am assuming the g1 wire is one to one with that. But being a pentode, it may not have any pitch match at all with the g2, so I could be mis-reading the g1 pitch. Since the g2 current remains fairly low, it does seem to have some alignment though. I only have two tubes, so I am reluctant to break one open to find out. It could also be that the g2 is wound at twice the wire spacing as the g1, which would give some alignment effects.
Well, in one of my more moronic moments, I managed to roach a half-dozen of them, so I guess I could break one open when I find the time. Remind me if I forget. The house is kind of a disaster right now and I'm in the middle of a guitar amp build, and screen drive experiments (screen drive rocks). If you are any good at guitar amps, I could probably use your advice.
Unfortunately, no good at guitar amps here. If you could take a picture of the g2/g1/cathode assembly some time, or just interpret what you see, would be great.
With screen grid drive, the linearity of most output tubes becomes phenomenal. At least 2X better Qfactor than the 300B. You want an aligned g2 though for low current drive.
With screen grid drive, the linearity of most output tubes becomes phenomenal. At least 2X better Qfactor than the 300B. You want an aligned g2 though for low current drive.
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The Williamson was supposed to be at the pinnacle of the valve era too. OK it's push-pull but there are those that state that push-pull was the way to go with tubes.
It was a great circuit, in my opinion, because it used good tubes and you could do fixed or cathode bias with it and it had the oomph to power just about any power tube u threw at it. I especially like the way he eliminated a coupling cap. I basically used the Williamson for inspiration with my screen drive amp; I borrowed a couple of ideas from it, and it works. I'm even driving 6P3S screen drive. it works.
I asked a guy who was, and may still be, smarter at this stuff than I am. I asked him, "what's the big deal with SE? I have heard a few SE amps and I frankly don't get it." His response was that you basically only saw SE on the cheapest (manufactured) equipment, it has more distortion, he had nothing positive to say about it. So, his statements (he's an engineer) basically confirmed my suspicions. I'm sure this also is going to step on toes. I'm not going to get into a great big long-winded diatribe about its alleged benefits. My speaker system requires serious power (15-inch active-passive bass modules). SE just would never cut the mustard for the way I like to listen to music. I like that deep, rich, smooth bass.
Full spectrum sound can easily be achieved with a low-wattage SE amp. If you require assistance with that I'll be glad to help. You'll probably need to upgrade your loudspeaker system first.
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I suppose I should dash out and buy a turntable too, and a pile of vinyl so I can listen to compressed, lifeless music from the "good old days." I'll get right on that
So, please enlighten me, how do I need to "upgrade" my speaker system? Please do share your recommendations.
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I'm sure the guys from Altec that engineered the 344a amp would be very pleased to know that in 2014 there'd be a long winded forum geek that knew more about tube amplification then they ever did.
Yep Guess everybody was just Elcheapo back then in the golden age of audio when tubes didn't cost anything, Altec, Rodgers, Leak, Beam Echo, Fisher, Scott, Sherwood, Dynaco, Mullard, Telefunken, Just to mention a few.
Glad I got schooled tonight I may have never known this. )
Cheers...
Yep Guess everybody was just Elcheapo back then in the golden age of audio when tubes didn't cost anything, Altec, Rodgers, Leak, Beam Echo, Fisher, Scott, Sherwood, Dynaco, Mullard, Telefunken, Just to mention a few.
Glad I got schooled tonight I may have never known this. )
Cheers...
Explain to the original poster why he should build an amp with the EL84. Use the data sheets, discuss costs, sound quality, distortion, all of the pertinent factors. I'm sure he'd be glad to have your wisdom. Other than ease (6V6 and 6L6 just as easy) you just haven't made your case. Everybody wants to foist the EL84 off on beginners. Like telling a guy his first date has to be with an ugly chick before he can move up to the better looking.
BTW, if you have proof tubes were cheap back in the day, provide it. Show the costs for a given year and then show what the average worker earned.
I remember what Pioneers, Sansui's, Marantz's etc, cost when they were solid state (way cheaper technology than valves) and it was beyond the reach of most unless they wanted to sacrifice. My brother could afford nice staff, he had a very good job. My sister could afford Marantz, she worked for the railroad. If I'm not mistaken tubes have never been as cheap as they are now.
When KT88's were 6 pounds{12.00 dollars} each i was earning 6 pounds a week.
Tubes were not cheap in Australia anyway.
phil
Tubes were not cheap in Australia anyway.
phil
i think I would have to somewhat agree.
That tube price list was from 1950. Minimum wage in 1950 was 75 cents an hour. So, you had to work an hour at your minimum wage job to afford a 12au7 or a 6L6, basically. So, it would appear tubes weren't really as expensive as I thought back then, but still, they weren't "cheap," and electronics definitely wasn't "cheap." I took a look at what various electronics cost a consumer back then, and a person would have had to work WAY more hours to buy electronic gadgetry back then than today.
Also, given that a 6n2p is better than a 12ax7 and I can get one for barely over a dollar at RUtubes.com, looks like tubes ARE much cheaper today. A factor that is conveniently omitted by the argumentative crowd who must be right irrespective of the facts: tubes were ubiquitous back then. There was no solid state. Now, if we were still in the tube era, would tube depot be charging 8 dollars for a Chinese tube that I can pick up for a dollar elsewhere? I think not.
Giving raw prices and not adjusting for inflation is misleading.
The discussion concerned EL84 and whether it was used for reasons of quality or economy. The EL84 isn't even on the list, having not been invented until 1953.
"The EL84 was developed to eliminate the need for a driver tube in radios, and has rather more gain than is usual in a power pentode, producing full output from a relatively small drive signal. This eliminated the need for a preamplifier triode in radios, making them cheaper to produce. As the EL84 itself is a 9 pin Noval, it was also cheap to produce and manufacturers were quick to adopt it in general use, and they are found in many old European valve radios and other audio equipment. A single EL84 was used in low-cost equipment, and a push-pull pair for lower distortion and higher power. Developed by Philips in 1953"
Note, manufacturers used it because it was cheaper.
That tube price list was from 1950. Minimum wage in 1950 was 75 cents an hour. So, you had to work an hour at your minimum wage job to afford a 12au7 or a 6L6, basically. So, it would appear tubes weren't really as expensive as I thought back then, but still, they weren't "cheap," and electronics definitely wasn't "cheap." I took a look at what various electronics cost a consumer back then, and a person would have had to work WAY more hours to buy electronic gadgetry back then than today.
Also, given that a 6n2p is better than a 12ax7 and I can get one for barely over a dollar at RUtubes.com, looks like tubes ARE much cheaper today. A factor that is conveniently omitted by the argumentative crowd who must be right irrespective of the facts: tubes were ubiquitous back then. There was no solid state. Now, if we were still in the tube era, would tube depot be charging 8 dollars for a Chinese tube that I can pick up for a dollar elsewhere? I think not.
Giving raw prices and not adjusting for inflation is misleading.
The discussion concerned EL84 and whether it was used for reasons of quality or economy. The EL84 isn't even on the list, having not been invented until 1953.
"The EL84 was developed to eliminate the need for a driver tube in radios, and has rather more gain than is usual in a power pentode, producing full output from a relatively small drive signal. This eliminated the need for a preamplifier triode in radios, making them cheaper to produce. As the EL84 itself is a 9 pin Noval, it was also cheap to produce and manufacturers were quick to adopt it in general use, and they are found in many old European valve radios and other audio equipment. A single EL84 was used in low-cost equipment, and a push-pull pair for lower distortion and higher power. Developed by Philips in 1953"
Note, manufacturers used it because it was cheaper.
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If you want to power "real" speakers can I suggest you buy commercial amps which chase the power. I prefer choosing the speaker to suit the amp and there are massive advantages in doing so.
You have obviously decided on a different path, but don't imagine that yours is the best way to get what it takes to call your system HIFI - it just sounds arrogant and foolish.
Shoog
"Who among us hasn't noticed how the lower powered amps just fell flat on their faces when you asked them to drive real loudspeakers"
We have differing opinions of what a "real loudspeaker" is.
I will agree that the EL84 was designed to be a cheepish easy to drive tube who's sound may be slightly over-rated. I also think that the 6V6 is slightly better sounding, but this is subjective and hardly a true comparison.
"You need power to make clean bass, you need clean bass to have an audiophile system."
Incorrect, you need to not waste your power to make bass. Your horribly inefficient speakers will make sure that you don't have any "clean" bass left, all the micro texture is lost.
In fact you may have less acoustical wattage from your PP then what some may have with their SETs with efficient speakers.
We have differing opinions of what a "real loudspeaker" is.
I will agree that the EL84 was designed to be a cheepish easy to drive tube who's sound may be slightly over-rated. I also think that the 6V6 is slightly better sounding, but this is subjective and hardly a true comparison.
"You need power to make clean bass, you need clean bass to have an audiophile system."
Incorrect, you need to not waste your power to make bass. Your horribly inefficient speakers will make sure that you don't have any "clean" bass left, all the micro texture is lost.
In fact you may have less acoustical wattage from your PP then what some may have with their SETs with efficient speakers.
Presupposing that my system isn't hi-fi when you haven't heard it is, well, foolish. This might sound like bragging, but I have had people who fancy themselves audiophiles listen to my system and none were less than impressed. And that includes the single-ended vinyl-heads. I heard their systems. They were flat out lame by comparison.
I know what I like in sound. The only loudspeakers I was ever impressed with had passive radiators. The bass is smooth, deep, and natural. That was the point I chose to start with. I then bought and eventually built an amp that could power it. I don't know why it is so difficult for you and your ilk to comprehend: Bass requires power. The only way around it I know of is horn-loaded which has its own shortcomings (extremely limited frequency response, for one) and I just don't care for horns. I know many do, I don't.
If I listened to people like you, I wouldn't have made any of the very rewarding discoveries I have made in this 6-year journey/quest for audio nirvana. I'd still be using those same old tired designs that most of you settle for. I have tried all of the speaker designs (as in BUILT THEM MYSELF) except for hornloaded. I did research it and decided against it.
And I'll leave you with this little thought. Stereo Review Magazine, in testing the Polk SDA1C (with passive radiator) stated, "we have NEVER tested a speaker with this little bass distortion." As I pointed out, if the bass isn't right, the rest of your efforts are pointless. The bass is the foundation of the music. I prefer to get it right the first time. I have an excellent sound system. I'll continue to try to improve it, but lately I have come to the conclusion that, short of spending a LOT more money, I think further significant improvements are unlikely. How many people have listened to your system and asked if it was for sale?
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