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Jack Elliano is one my favorite guys in this hobby. Definitely an explorer, and criticized for it sometimes, but he's also a measurement nut. He has been doing a bunch of work lately on IM distortion, which isn't talked about much, especially with SE designs. I mentioned this before, but I really think he's on to something. He's made an elaborate calibrated test setup to test IMD and has been experimenting away. I promised not to tell all that he's found out for whatever his reasons are. But I can say that he's found that most SE amps have at least 5-7% IMD (in addition to HD)at full power, and that he's lowered that to less than 1%. He's also made a unity coupled style OPT (PP) where he's getting 60W from 2 6CA7's with stupid low IMD and HD without FB! He says he wrote an article about this, but I can't find it.
Here's a bit off his website about his new "A3" OPTs.
He does make a few statements about silver wire, he usually won't do that unless he's measured something. Note: I haven't heard any of it!
Also note: he's an accessible guy, give him a call and ask him if he measured something if you're curious.
TRANSFORMER DESIGN
Electra-Print’s new design 300A3 output transformers have the following features when compared to traditional designs
* Lower tube generated even order harmonic distortion per given amplitude rise.
* Lower intermodulation distortion (IMD) per given amplitude rise.
* Lowest interwinding capacity of most standard SE outputs of this size.
* Lower secondary to primary shunt capacity resulting in little or no distortion products generated from output tube.
* Winding technique for least gradient winding capacity, resulting in a very high self resonance out of usable audio range.
* Core material is M19, proven in all magnetically biased (plate current) devices, to offer the widest and most constant permeability resulting in less impedance change over the audio spectrum. Larger core mass used for less low frequency HD and IMD products.
* Silver and partial silver windings offer a 200% increase in sensitivity over copper as a secondary, resulting in an increased in music detail or very low flux variations being induced as current. All transformer primary windings are solid copper.
* Bandwidth of all transformers listed, is within -1db from 24Hz to 25kHz+ and power output is relative to circuitry parameters given, approximately 10 watts at clipping for standard 300B.
Follow Ups:
My friend says the way Jack Ellinao present thing and talk like a "non graduate" from junior high, then why bother??
His irons is full of bullshit, how can silver have 200% increase in sensitivity over copper?? I know fellow built thing with Sacthailand and Sowter; they just blew away Electraprint with same circuit??
A3?? What the hell is it??
"He says he wrote an article about this, but I can't find it."
Well, that's the most important part of your post. No one can even discuss it here without knowing the principles being considered.
The rest of your post looks like a transformer advertisement. The only thing you left out was pricing.
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Buy Chinese. Bury freedom.
My original post had no reference to the article, and I said that because I couldn't find it. I didn't need it personally, as I'd heard it from the source. I mentioned it's existence for the benefit of those who might be able to find it, and exactly that happened in just a few hours.
Wheezer found it and posted a link below, well before your post. wake up.
Think what you want of Jack's efforts, I could care less.
"Wheezer found it and posted a link "Would that be the link to the Electra-Print advertising page or the link to the thinly-veiled, self-serving promo disguised as a treatise on IMD? Neither mentions "6CA7s with stupid low IMD" or a claim that "most SE amps have at least 5-7% IMD."
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Buy Chinese. Bury freedom.
Edits: 09/06/12
While I polish my lying skills for the next round of fraud and deception.
I want to believe because his trans are affordable and since transformer winding technology in the tube amp mainstream(non supa expensive) Has pretty much devolved from distributed loading decades ago. Surely there is potential for another quantum step forward. It would be nice to see some nice distributed load trans for el34 2a3 300b hit the market. And more cathode feedback windings! Is there a good reason why they disappeared other than cost? That and pie winding. Some nice machined Teflon pie winding bobbins.But since he is still using EI and not C or o its seems unlikely. I read last night in EI iron dominates in CC copper dominates.
I would like some more learned folks advice or opinions on some generalizations I have been logging in my brain randomly about trans?
Would it be fair to say that EI is a softer less stable image with less mid bass attack but possibly more warmth possibly second harmonic??
As apposed to CCore more image stability more forward vocal image more midbasss attack? less second harmonic?
And finally Is paper insulation verses teflon always warmer softer compared to teflon being harder and cleaner like a cap or is it more likely paper insulation due to increased capacitance a cause a grain and hardness all of its own?
I believe magnequest use teflon and they sound the warmest to me in my gear sofar.
I am still considering winding some of my own trans from what ever cores I can recycle there is a new cnc winding machine on ebay for $1200. The idea of used cores appeals to me despite the knowledge that steel can break down in composition with age.
Edits: 09/06/12
I would also like to see more OPTs with cathode feedback windings. Sometimes a pair of old Mac OPTs will come up on eBay, but they always sell for astronomical prices.
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Buy Chinese. Bury freedom.
I would love a pair of quads to play with. Maybe not in the class of the macs but still good but ditto on the cost.
"THD can be carefully tuned out of a circuit to offer a very clean and lifelike delivery and this is done routinely in amplifier circuit design. On the other hand, IMD can be generated and/or increased while THD is being cleaned up witihn the circuit."
I think the second sentence here is happening all the time in most of our SE amps. It may be hard without similar elaborate calibrated test equipment for mere mortals to tune as he suggests, but there are several components of his overall design that can be implemented, at least getting closer to his results. As I've said before, this tuning takes place with the tubes you commit to, changing them "might" be ok, but the odds are low that you'll have two extremely identical specimens.
I think this is interesting! I plan to get at this when I can.
Isn't Jack Elliano the individual who proposed driving a 211 with an opamp? You know, being a transformer designer isn't sufficient to lend credibility to one's circuit design abilities. They're very different skill sets.
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Buy Chinese. Bury freedom.
I believe his understanding of circuits and implementation Precedes his involvement in transformer manufacturing. He's not stuck in any particular closed minded "only triodes" or "only tubes" or "only no NFB" etc etc..
Which makes following his work interesting (to me).
I'm seen some of his experiments that were not so interesting along with more that are IMHO.
I posted this more recent avenue he is pursuing because I thought it genuinely would be of interest and merit to at least some on this forum, that's all.
I'd be more intereseted in his work if he knew what he was talking about.
Regarding 211 Class A2 operation, he says,
"Unfortunately no tubes can offer this drive capability..."
That's untrue, of course, and after seeing this junk, I've completely written him off for circuit design:
This doesn't mean he can't design a mean transformer, though.
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Buy Chinese. Bury freedom.
My friend has a 300B PP version of this circuit. I had that sucker in my home with those huge OPTS. It sorta sounds like big Japanese SS amp and would be fine in Home Theater setup , otherwise -bass amp up to 100hz no more. You know , with more than decent OPT and transparent output stage the only thing you're going to hear is that damn TDA2030 0.50$ power Opamp.
I've used and still have his TM3KB OPT and it's as good as anything in that price bracket and quite a bit more. He offers good quality for good price , I don't care what he does with his free time (i.e circuit design etc). But the thing I respect him the most is that he said F..Off to all that "low DCR crowd" and stopped winding Power Transformers and chokes altogether.
Not sure when it went up, but found a link.
Jack may have his opinions and not a little bit of attitude, but it always looks like he's having some fun.
Find one thing you just don't like the look of (the schematic)
(of course, you never heard it, nor have I)
and then toss all prior or subsequent work because it must all be "junk"
Makes sense.
Of course I haven't heard it, nor do I want to. I've heard enough junk opamps to last two lifetimes. That's why I build with tubes.
"toss all prior or subsequent work"
Everything I quoted is currently on his site. The circuit uses his transformers and represents his best technology. He can't say enough good about it.
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Buy Chinese. Bury freedom.
It's sad I must remind you that I never mentioned his A2 op amp driven 211 amp.
How you fixated on an unrelated "disappointment" in your view, and then tried to bootstrap it to my "report of his findings" on a completely different subject, I don't know, but if it pleases you to bicker, bitterly time after time, then fine.
"It's sad I must remind you that I never mentioned his A2 op amp driven 211 amp."
No sadder than reminding you that "credibility" can be thoroughly researched at the Free Dictionary. That's why I raised the issue. If you can't stand to have the credibility of your sources questioned, maybe you shouldn't quote them.
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Buy Chinese. Bury freedom.
if you question the credibility of the source, that's appropriate.
But your method of dis-crediting returns us partially to the whole subjective objective issue. Plus what ever possibly could be gained
in your favor will be ignored for what you've convinced yourself as good reasons. Again, if this feels right and productive to you, then fine.
IM levels generally follow harmonic distortion and are usually not an issue in amplifiers below 0.5% or so THD. TIM does not behave that way, and is much more likely the cause of many of the anomalies we hear but fail to measure.
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Buy Chinese. Bury freedom.
.
Lynn Olsen has a great story about TIM when he was with Audionics in Oregon.
It's also a tribute to a great audio design engineer who has passed on.
Transient Inter-Modulation distortion. It relates to how an amplifier reacts to tranisents, changes in input signals that are non sinusoidal.
Usually, IMD (Inter Modulation Distortion) is measured using two sinsoidal sources of equal amplitude but different frequencies, e.g., 400 Hz and 1000 Hz. In a perfect world, only signals with frequencies equal to those of the input (400 Hz, 1000 Hz) should be seen at the output of the amp. But, more likely, "beat" frequencies equal to some integer multiple of the sum and differences of the input signal frequencies will be present as well.
To quote:
"A device that adds IMD to its output signal will have unwanted frequency components generated at specific frequencies. The third-order products will occur at a frequency of (2 • f1 - f2 ) and (2 • f2 - f1 ), showing up as extra frequency components Δf above and below the two input frequencies. Fifth-order IMD will show up as extra frequency components above and below the third-order distortion, exactly Δf apart. The other odd-order IMD products follow suit."
Tiny Tim, a no-longer-with-us ukulele player with a falsetto voice. Got married to Miss Vikie on the Johnny Carson show.Also, in audio ..... about 1972, introduced by Matti Otala .....Transient Inter-Modulation distortion, as opposed to the more common this torsion and that torsion as described by J.Gordan Holt.
See, ...science is easy.
Jeff Medwin
Edits: 09/05/12 09/05/12
Are the lower distortion numbers due to his OPTs or how he is measuring and evaluating the data?
Since this is apparently some proprietary measuring process, we really can't know what he is doing.
Are you going to buy these OPT's and experiment on your own to see if the claims match up with reality?
dt 667
I have no immediate plans to consume more audio parts at the moment.
And, I believe the low IMD results are from a combination of OPT design, circuit considerations, and specific OP tuning for the exact tubes used.
This means tube rolling is out.
"And, I believe the low IMD results are from a combination of OPT design, circuit considerations, and specific OP tuning for the exact tubes used."
Don't forget line voltage, component values, power supply impedance and load. Wow, this promises to be a real breakthrough!
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Buy Chinese. Bury freedom.
Actually, it seems like it might be a little breakthrough,
which is why I started the thread.
"pissed on again"
But not by me. There's nothing substantive in any of the linked pages on the topic of reducing IMD. Every explanation and claim outside established theory is cloaked in generalities, inuendo and pretentious jargon. It's absolute, intentional BS, and I would never do that to you or any other Asylum contributor.
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Buy Chinese. Bury freedom.
his response:
This is a new way to operate an output tube to achieve lower IMD and higher power levels. The output transformer we have for this lowers IMD about 50% then additional associated circuitry lowers the rise or amplitude of IMD. Circuit generated IMD has one unique feature, it is amplified also.
There is some good info on our site and also at the Electra-Fidelity site. This is our sales site.
No need to keep if off the forums, I have been reading them on and off. Ralph Karsten from Atmo sphere, has been very helpful on these sites explaining it to everyone, he knows what this is all about!
Here is our site info http://www.electra-print.com/a3transformer.php
Here is EF site on IMD http://www.electrafidelity.com/intermodulation-distortion-imd/
Jack Elliano
Electra-Print Audio
www.electra-print.com
Hi GSH,
Are we measuring the right things ???? How meaningful are full power THD and IM distortion figures - and optimizing for full power in one's amp designs, when a typical SE low power amp is rarely hitting full power, and , on 98 dB efficient speakers, stays at a small fraction of one Watt most of the time.
Might there be a better way to measure SE amps, more in tune with how it is used 99% of the time? Just a friendly question to ask. But not a dumb one IMHO.
Jeff Medwin
Jack likes to push everything to the max, it's well known, it's the pyrotechnic in him. I admire the kid in him, he's having fun, and probably enjoys blowing things up sometimes. I guess I would too!
And, if one amp produces 5-6% LESS IMD than another, both at full power,
then there's still a significant benefit a lower outputs, of course.
He has found that reducing IMD to the degree he has been able to makes
a "newish" sonic improvement. He calls it "no congestion at all until reaching nearly full output." or something like that...
Hopefully someone will find the article, it might be in a subscription magazine, not on line however, don't know. I'll ask next time.
~!
The Mind has No Firewall~ U.S. Army War College.
No doubt, you have read the information on the Electra-Fidelity website:http://www.electrafidelity.com/intermodulation-distortion-imd/
http://www.electrafidelity.com/silver-45-se/
A little info can be gleaned from them...
And this, from an A'gon post:
" ..was very supportive of Jack's effort and the result is that we now have two amplifiers in production that will operate in Class A3. The A3-500 is a 300B SET amp with a circuit designed by Jack Elliano that puts out roughly 10 watts.""I would not say that the design is necessarily unique from traditional Class A, but it is different in that while the product of the plate power on the output tubes might be the same in both classes (ex. 300B tube), the voltage in an A3 circuit is higher and the current is lower. Since the power is developed by more voltage the result is more lifelike dynamics. This holds true only if the tube can take the increased voltage in A3. Not all can. We could not do this with a 45 or 2A3, but the 300B and EL-34 were rugged enough to take on the increased voltage."
"What has also been accomplished using this Class A3 circuit is a drop in THD and more importantly IMD. Measurements indicate a lower noise floor as well."
It appaears not just the transformers, but an approach to amp design that uses A3 operation?
Cheers.
“As long as we have any intention to be right… we should be wary. So long as words have the slightest ego attachment, they are dishonest.” Charlotte Joko Beck
Edits: 09/05/12 09/05/12
I talk with Jack fairly often, so my info is from mouth to ear primarily.
I couldn't find the article, I guess I looked at the wrong site. But now I will go try to find it again. thanks
I'm sure they are great transformers but WTF is this all about:
"Silver and partial silver windings offer a 200% increase in sensitivity over copper as a secondary, resulting in an increased in music detail or very low flux variations being induced as current"
Dan
nada aqui
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Buy Chinese. Bury freedom.
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