There is plenty of opportunity to produce a low distortion SE amp.SY said:
Can you more than 'speculate' about the importance of a plain THD figure?
Do you not have an unqualified preference for the sound of a balanced amp?
I concede size, efficiency and all that goes with it but not sound. It can be done.
It just needs to be larger or it will produce more even harmonics 🙂
Plain THD figures are not nearly as useful as spectral breakdown, which is why you'll always see me use the latter.
Many sins hidden in that innocent-sounding phrase. Size carries electrical penalties.
Yes, granted, but the breakdowns you have been mentioning are not appealing to me. They seem no more than a "mine's smaller than yours" kind of thing.SY said:
Yes, a large OPT is a big ask, but there are always high efficiency speakers, and the seasoned DIYer is not afraid of such a challenge, if the payoffs are worthwhile.
Now we have stumbled upon one of the greatest audio myths of recent years: The appeal of the single-ended amp is that its harmonic spectrum colors the sound and seduces the listener with syrupy, sweet unrealistic sound. The listener is like a child and doesn't realize this and stubbornly sticks to this illusion.
Some of the most accurate, lowest distortion systems I've heard featured ZNFB single-ended amps. Believe me, I went into it with expectations of euphonic sound and never heard it. Mind you, these amps generally have the highest quality output iron and would be expensive even for DIYers. My own experience with the cheap single-ended amps with Edcor, Transcender, old console SE-OPTs, etc. is they are JUNK and don't qualify as anything.
John
Some of the most accurate, lowest distortion systems I've heard featured ZNFB single-ended amps. Believe me, I went into it with expectations of euphonic sound and never heard it. Mind you, these amps generally have the highest quality output iron and would be expensive even for DIYers. My own experience with the cheap single-ended amps with Edcor, Transcender, old console SE-OPTs, etc. is they are JUNK and don't qualify as anything.
John
Your characterization and not mine. I've greatly enjoyed some SE-based systems I've heard (most notably the one that I heard in the basement at ETF05) without me feeling even the least bit child-like. Realistic they weren't, especially on complex and loud material. But very enjoyable. So what? Are the purity police going to put a clamp on tone controls and equalizers?
Your experience and not mine. The systems I am familiar with had the highest quality components from top to bottom. A Lamm shunt-reg 6C33B amp driving Kharma Exquisite speakers with Koetsu Jade Platinum-Walker Proscenium > Aesthetyx Callisto > Aesthetyx Io had no problems whatsoever with the Brahms B-flat piano concerto.
Obviously not my own system🙁
John
It'll be interesting to examine further as my experience mirrors jlsem's, though domestic circumstance don't permit examination at the loud end of the scale. The 6CN7 circuit mentioned earlier (jlsem, not mu follower, simple grounded cathode DC coupled to a double-choke loaded cathode follower) is the front end of a transmitter tube based SE that with the benefit of a little second order cancellation makes about 12 watts at 0.6% THD, strongly second. Quick listens on the bench were very, very promising. It should be at least a good data point in determining if no-GNFB SE is 'too sweet' due to high levels of 2nd.
The idea that "old transformers are bad" originated half a century ago. Back then it was true. Not now.
I have mentioned this once before. (I don't have that many of these stories to tell.) I sold a pair Telefunken balancing/step-up transformers from the 1950s or 60s to a guy in America. I was a bit hesitant shipping them since he has a pretty impressive sound system, including a Reimyo PAT-777 with NOS WE 300Bs, various Shindo and Auditorium 23 gear. Perhaps most important here, he had some swank new step-up transformers. He loved the Telefunken trafos, especially the highs, which now were more open and clear.
The Telefunken V 69 mono unit cost the equal of two months' salaries in the 1950s. There's no inch thick aluminum front plate or anything like that. You got three transformers and four tubes mounted on a steel plate and that's it. The Telefunken U73 was the fastest compressor of its time and many consider it the best ever. Virtually all European vinyl from the 1960 through the 80s was cut on it. It was so expensive few units left Europe. (Musicians are as big hams as audiophiles. Historic studios, provenance are huge with musicians. "Richie recorded here" will automatically make that studio better than all other studios. "Jimi shot smack here" will do the same for any hotel room. Since the Beatles used the U73, lots of units have since reached America.)
This gear was heavily subsidized. I was "cost-no-option" gear, often made specifically for state-owned TV stations. The "V" numbering system used by Telefunken, Siemens, Neumann, Funkwerk, Maihak (who manufactured the V 69), etc. is the result of this. It seems they used the same system later used by the Japanese electronics giants in order to keep cost down. For example, it seems like Siemens made all the transformers used by these companies, usually labeled BV-XX, like the legendary Neumann BV-33 step-up transformer. By that time it seems Haufe had taken over the transformer production.
I have mentioned this once before. (I don't have that many of these stories to tell.) I sold a pair Telefunken balancing/step-up transformers from the 1950s or 60s to a guy in America. I was a bit hesitant shipping them since he has a pretty impressive sound system, including a Reimyo PAT-777 with NOS WE 300Bs, various Shindo and Auditorium 23 gear. Perhaps most important here, he had some swank new step-up transformers. He loved the Telefunken trafos, especially the highs, which now were more open and clear.
The Telefunken V 69 mono unit cost the equal of two months' salaries in the 1950s. There's no inch thick aluminum front plate or anything like that. You got three transformers and four tubes mounted on a steel plate and that's it. The Telefunken U73 was the fastest compressor of its time and many consider it the best ever. Virtually all European vinyl from the 1960 through the 80s was cut on it. It was so expensive few units left Europe. (Musicians are as big hams as audiophiles. Historic studios, provenance are huge with musicians. "Richie recorded here" will automatically make that studio better than all other studios. "Jimi shot smack here" will do the same for any hotel room. Since the Beatles used the U73, lots of units have since reached America.)
This gear was heavily subsidized. I was "cost-no-option" gear, often made specifically for state-owned TV stations. The "V" numbering system used by Telefunken, Siemens, Neumann, Funkwerk, Maihak (who manufactured the V 69), etc. is the result of this. It seems they used the same system later used by the Japanese electronics giants in order to keep cost down. For example, it seems like Siemens made all the transformers used by these companies, usually labeled BV-XX, like the legendary Neumann BV-33 step-up transformer. By that time it seems Haufe had taken over the transformer production.
Good points. When you first read about the SET you are innundated with stories of colouration.
My amp does not sound like honey, syrup or any other plant extract. Sure, I grew up listening to single-ended mantel radios and the like, and for that reason I don't mind the sound, but I don't prefer it and I wouldn't call it hi-fi.
So you need to build one yourself to hear it. Then you discover inverse distortion cancellation. This has a practical effect that bears resemblance to balancing, interestingly enough.
My amp does not sound like honey, syrup or any other plant extract. Sure, I grew up listening to single-ended mantel radios and the like, and for that reason I don't mind the sound, but I don't prefer it and I wouldn't call it hi-fi.
So you need to build one yourself to hear it. Then you discover inverse distortion cancellation. This has a practical effect that bears resemblance to balancing, interestingly enough.
SY said:
All that DC also is an anavantage in the sense that it moves the middle of the transformers operating point into a linear part of the BH curve. In a PP amp (or parafeed SE) the signal has to pass thru the non-linear part of the BH curve and the energy to flip the curve over has to be robbed from somewhere.
dave
(PS i'm in neither SE or PP camp, i have heard really good amps of both varieties -- and even more not so good ones)
lndm said:
A myth to be 'Debunked':
An amplifier with more 2nd than 3rd Harmonic distortion
is a better sounding.
Take this example:
Amp A)
2nd harm: -60 dB
3rd harm: -70 dB
Amp B)
2nd harm: -80dB
3rd harm: -70 dB
They BOTH have same amount of 3rd harm distortion.
But why prefer Amp A, as this one has more 2nd harmonic than Amp B.
Amp B. has got as much as 20dB less of 2nd harm dist!!!!
*** fotenote *********************
Distortion:
The degree of which the input signal has been destroyed
measured at the output.
Hifi, high fidelity:
The quality where input signal is a little as possible destroyed by the amplifier.
Signal stays very much the same = High Fidelity
In-Fidelity:
The opposite to Fidelity 😉
Regards, lineup
The second masks the third, according to the argument. That may or may not be true; I'd like to see more evidence and less assertion and less analogy.
I believe it was covered in a study 70 odd years ago.SY said:
What I know is, when my amp transitions through a high 2nd harmonic stage of development I get a craving for more 3rd harmonic, or more bite. When I have too little second I crave more warmth to mask the bite.
So I don't believe that one masks the other so much as I think there is a partnership, or a natural balance to things. But how do I prove this to others? I certainly don't need to prove it to myself. I believe that the natural balance theory should be the default, and that it should be the one to be disproven.
Why not just use an amp that makes the input signal bigger without adding bite or warmth? Radical concept, I know...😀
Haha...
Can't recall listening to an amp that had life, that didn't have character. There seems to me to be another myth in the practical world that when distortion gets low it becomes inaudible.
Can't recall listening to an amp that had life, that didn't have character. There seems to me to be another myth in the practical world that when distortion gets low it becomes inaudible.
planet10 said:
So you're saying that DC current in the transformer's primary will linearize it?
se
Some DC bias in an output transformer will insure that signal stays within the linear part of the magnetization curve. This is fairly well-proven and really isn't subject to much debate.
John
magnetic hysteresis
I don't think dc bias has any effect on the linearization of signal tracking in an output transformer. It's not analogous to bias frequency in a tape deck, which linearizes the recording signal with hf, not dc signal.
Hysteresis is an ac event, not a steady state situation.
A different mechanism completely...
I don't think dc bias has any effect on the linearization of signal tracking in an output transformer. It's not analogous to bias frequency in a tape deck, which linearizes the recording signal with hf, not dc signal.
Hysteresis is an ac event, not a steady state situation.
A different mechanism completely...
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