Yes. Also, amps that measure differently can also sound the same to listeners. Why? That's because today's audio measuring devices can detect far beyond what people can hear.So you are saying that amps that measure the same sound the same.
Look up audio measurements.With typical steady state measurements yet?
No, they are not crude these days. Contemporary audio measurement technology can display far beyond what you or anyone can hear.measurements are just too crude to capture the complexity of the interactions.
I thought the discussion is about electronic audio signal amplifying device.Add humans listening to music and there is not much science in it.
The fact is that although measurements are empirical (not objective), they are largely based on what and how we can measure. The test signals are not music and the setups do not track transient interactions with a time dimension. But the biggest problem is that there is no "listening brain" plug-in for the meters.
You are free to say what you want.I say that they are not objective because the measurement systems and electronic evaluation criteria are cultural creations.
Ever heard of brainwave scanner? It shows the changes in our brain what we think/feel but this isn't part of amp discussion.They are not written on tablets handed down from the heavens. We made this stuff up and we agree, more or less, that it is good. But they are "empirical" data, which is what I think you are really meaning to indicate. Solid hard data, right?
Well, I haven't met anybody smart enough to conclusively link those digits to subjective listening impressions beyond general vague statements that have the ring of truthiness and sound eminently sensible in audio forum threads.
I'm the one who is trying to stay with amp discussion, no?And if you believe in strict correlations between distortion and listening satisfaction, I suggest you don't participate in SE amp threads because there is a hella lot of distortion around here!
What you listen to is the replay of recorded musical performance. I suggest going to the live music performances if you are that emotionally into it.Precisely. I am counting emotional recreation in my evaluation, since that is why I listen to music.
See above. Plus, there is nothing like live sound. 😉Aren't you looking for musical enjoyment above all?
I know what you are getting at, Evenharmonics, but the topic is too deep and critical to be left to generic forumspeak answers. And also too complex, interactive, and granular to be summed up by a few convenient sound card measurements.
Let me ask, which SE amps are you listening to and what is their measured distortion? And do your subjective impressions track the distortion ratings exactly for all of the SE and other amps you've heard and measured?
If not, why not?
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Comparison of live sound vs. replayed sound is subjective.In fairness, we should remember that this is a supposition.
Thanks, as always,
Chris
I think another way of using the Pass metric would be to ask, "What is the most competently designed SET amplifier design that has been ever designed with respects to all aspects of amplifier performance?" I think it is a fair question and there was an amp I found a while ago that fit the bill but now I cannot remember the name. It did use some old fashion tech by using tubes to regulate the power supply and ran 300b tubes (I think). It was a beast but I can't find any info on it now.
audioexplorations unfortunately there isn't an equivalent to any of the Pass amps in the tube world. I have looked for this myself and nothing really fits as far as SET is concerned. Tubelabs SE is an easy design and a great place to start but I would not say that it follows the footsteps of Pass. The red light district would be the closest thing available if you were looking in to a push pull amplifier and it may be something you want to consider depending on your power requirements. It would not be hard to use Pass Zen "guidelines" to create an amplifier maybe you will have more luck than I have trying to get the people on this forum to work together on such a project so there.
You could just try to convert the zen V9 into a tube version utilizing a similar design.
audioexplorations unfortunately there isn't an equivalent to any of the Pass amps in the tube world. I have looked for this myself and nothing really fits as far as SET is concerned. Tubelabs SE is an easy design and a great place to start but I would not say that it follows the footsteps of Pass. The red light district would be the closest thing available if you were looking in to a push pull amplifier and it may be something you want to consider depending on your power requirements. It would not be hard to use Pass Zen "guidelines" to create an amplifier maybe you will have more luck than I have trying to get the people on this forum to work together on such a project so there.
You could just try to convert the zen V9 into a tube version utilizing a similar design.
Another issue worth considering is whether the "single-ended"-ness is an important element or a fallout of some other, truly important, design element, like simplicity.
For example, two identical "SET" amplifiers per channel are driven in parallel either in or out of absolute polarity ("phase" if you really must) and outputs combined (allowing for the polarity variations - easy with transformers). This gives no advantage in power supply immunity to the opposite polarity pairs of a true push-pull amplifier , but isolates the issues of distortion harmonic spectrum from issues of monotonicity and details of amplifier design.
Blinding this test should be fairly straightforward. I hope to have some answers for myself sometime upcoming.
All good fortune,
Chris
For example, two identical "SET" amplifiers per channel are driven in parallel either in or out of absolute polarity ("phase" if you really must) and outputs combined (allowing for the polarity variations - easy with transformers). This gives no advantage in power supply immunity to the opposite polarity pairs of a true push-pull amplifier , but isolates the issues of distortion harmonic spectrum from issues of monotonicity and details of amplifier design.
Blinding this test should be fairly straightforward. I hope to have some answers for myself sometime upcoming.
All good fortune,
Chris
Comparison of live sound vs. replayed sound is subjective.
I didn't say anything about subjectivity. I said that the quoted statement was a supposition, meaning that it was a possibility among many, and far from received truth. Might be true, but not proven or widely accepted. (Though I might likely agree, without better evidence.)
Thanks,
Chris
Quote:
Originally Posted by Joe Roberts
So you are saying that amps that measure the same sound the same.
Quoth Evenharmonics:
Yes. Also, amps that measure differently can also sound the same to listeners. Why? That's because today's audio measuring devices can detect far beyond what people can hear.
Know what I think...you have not in fact tested your assertions and you are speaking from belief.
In order to legitimately make the general statement that "all amps that measure the same sound the same," you would have to measure all amps and listen to all amps,,,in fact you would have to have every listener on the planet listen to every amp that measured the same and not hear any difference.
This is silly talk, to say that all amps that measure the same sound the same. In any case, it is something you can never know.
But for some reason it is fashionable in some quarters to make this untenable assertion.
You can't fool me.
On the other hand, ONE instance of an amp that measures the same not sounding the same is easy to find. I have changed single resistors in amps and they sounded different. I think one would be hard pressed to measure the difference.
This is the difference between deductive reasoning and inductive reasoning. One negative instance destroys the deductive argument you make. One negative result in my argument, only implies that the argument does not hold in that specific case. I am not making a general universal claim like you are (on insufficient evidence, yet).
But enough lessons on basic logic.
I get to hear lots of audio gear. I'm in the audio business. I have heard untold piles of super high end, high spec gear that really sounds boring and even bad. i just don't buy the arguments that suggest specs track sound quality. I have to go with my experience on this one.
On the other hand, I have heard moderately high distortion amps sounding quite realistic and not flawed to the degree the numbers would indicate. I can't fully explain it, so I don't try.
Yes. test gear has incredible resolution but it does not map musical listening. These are two different enterprises and the correlations have not been determined, beyond a few obvious generalities.
So, back on the topic of amps, let's hear about your experience of SE amps and how their subjective results track the measurements, Evenharmonic.
Until then, sad to say, you are not invited to my birthday party.
We still don't know what the OP wants. We are telling him what we want.
I get to play with very sophisticated implementations of SE typologies well beyond what most have heard and I have built dozens of simple amps myself. For a DIYer, entering the ring, I'd suggest something very simple as a learning exercise and a fairly reliable path to "good" sound. Start with the classic all tube 1935 circuit then branch out from there.
I have had this very discussion with literally hundreds of SE noobs over 25 years. Nobody has come back complaining after they built a decent amp that worked pretty good.
Four to five watts is actually a bit of an in-between point for commonly-available DHTs. The 2A3 is just below and the the 300B just above. The 50 is a gorgeous tube and I think they make a new version in China. That's 4-5 watts. Personally I'd build a modest-powered 300B amp with the best parts and tubes you can afford. There are a number of boutique 300Bs that all have different tones. Joe's WE91 clone is still a lovely-sounding amp, and with premium parts it can really be satisfying. I like Thorsten Loesch's version with an EL34 driver, it's a bit beefier for my system, but the WE91 clone is a very musical little amp.
Another option would be a low-powered 845 amp--that's quite a sound, the 845.
Lots of amateur designers have tried their hand at making SET amps more complicated, worrying about distortion and bandwidht and such. To my thinking simpler is better--there's only so much you can expect from this sort of amp, why not go for tone and musicality?
Another option would be a low-powered 845 amp--that's quite a sound, the 845.
Lots of amateur designers have tried their hand at making SET amps more complicated, worrying about distortion and bandwidht and such. To my thinking simpler is better--there's only so much you can expect from this sort of amp, why not go for tone and musicality?
Subjective evaluation can only have supposition as the outcome if one wants to report it.I didn't say anything about subjectivity. I said that the quoted statement was a supposition, meaning that it was a possibility among many, and far from received truth. Might be true, but not proven or widely accepted. (Though I might likely agree, without better evidence.)
Thanks,
Chris
You are wrong. I've been through level matched double blind listening test of amps. The two identical sounding amps measured similar but not same.Know what I think...you have not in fact tested your assertions and you are speaking from belief.
Something tells me that you've never been through the test I mentioned above, right?In order to legitimately make the general statement that "all amps that measure the same sound the same," you would have to measure all amps and listen to all amps,,,in fact you would have to have every listener on the planet listen to every amp that measured the same and not hear any difference.
This is silly talk, to say that all amps that measure the same sound the same. In any case, it is something you can never know.
But for some reason it is fashionable in some quarters to make this untenable assertion.
You can't fool me.
On the other hand, ONE instance of an amp that measures the same not sounding the same is easy to find. I have changed single resistors in amps and they sounded different. I think one would be hard pressed to measure the difference.
This is the difference between deductive reasoning and inductive reasoning. One negative instance destroys the deductive argument you make. One negative result in my argument, only implies that the argument does not hold in that specific case. I am not making a general universal claim like you are (on insufficient evidence, yet).
But enough lessons on basic logic.
I get to hear lots of audio gear. I'm in the audio business. I have heard untold piles of super high end, high spec gear that really sounds boring and even bad. i just don't buy the arguments that suggest specs track sound quality. I have to go with my experience on this one.
On the other hand, I have heard moderately high distortion amps sounding quite realistic and not flawed to the degree the numbers would indicate. I can't fully explain it, so I don't try.
Yes. test gear has incredible resolution but it does not map musical listening. These are two different enterprises and the correlations have not been determined, beyond a few obvious generalities.
So, back on the topic of amps, let's hear about your experience of SE amps and how their subjective results track the measurements, Evenharmonic.
Until then, sad to say, you are not invited to my birthday party.
We still don't know what the OP wants. We are telling him what we want.
I get to play with very sophisticated implementations of SE typologies well beyond what most have heard and I have built dozens of simple amps myself. For a DIYer, entering the ring, I'd suggest something very simple as a learning exercise and a fairly reliable path to "good" sound. Start with the classic all tube 1935 circuit then branch out from there.
I have had this very discussion with literally hundreds of SE noobs over 25 years. Nobody has come back complaining after they built a decent amp that worked pretty good.
. I've been through level matched double blind listening test of amps. The two identical sounding amps measured similar but not same.
Quote:
That's one test. not generalizable to all cases, which is the absurd claim you were making above about ALL "amps measuring the same sounding the same"
Double blind testing is totally flawed. I can go into it in enormous, encyclopedic detail but first let me know your educational level and qualifications to evaluate human research design.
I have two Ivy League degrees in this subject and did two PhD programs in relevant material and I can assure you that only rubes who do not understand the topic fully make strong claims about double-blind testing.
...but that will be getting way off the subject of SE amps.
Lets hear about your actual experience with SE amps, measurements, and correlations between the two.
. . . That's because today's audio measuring devices can detect far beyond what people can hear. . .
The interpretations of the measured quantities, measurement methods, and list of quantifiable items to measure, however, are still being investigated. My opinion is that the measurement art is still in the development stage, critics are the prerequisites to to a new level of understanding. Engineers left out (what the consensus at the time thought as) irrelevant data which at a later time were found to be quite significant. I do not suppose that everybody is happy and wish for the art to stagnate, even those saying tests are flawed.
Moreover, different people hear differently; some people are trained musicians, some partially tone deaf and others are totally deaf. I must admit that I was trained as a musician during junior and highschool years but currently one of the partially tone deaf, I can no longer hear 14kHz and above sinusoidal tone. So when I say 2 systems sound similar does not mean others will agree. But I still enjoy and tweak my "continuously under development" system.
Guys, wow, been away from the computer for just over a day and I come back to 5 pages of posts! Thanks for all who have posted, both there and via pm! I have read through the responses but I will need some time to take it all in, there is a lot of info to research and process - I am completely new to tubes.
One thing is for certain, it is not a straightforward as I had thought. The rabbit hole goes deep in the world of tubes (which I like - a lot to learn). There are countless options out there, and I guess a starting point would be to determine which output transformer and tube to go with. 2A3 or 300B seem to be the lead candidates. A lot I need to go research but thanks for putting me on the right path.
To answer some of the questions re clarification what I am looking for. As JZatopa put it: "the most competently designed SET amplifier design that has been ever designed with respects to all aspects of amplifier performance" is a nice way to describe it (however likely a lot of debate what this might mean). Other than this, and a general need for around 4 watts of more (I am running 95dB speakers), I don't really know what I need, am pretty much open to anything. And to answer another poster's question, I do not share the 2$ mentality when it comes to building amps, I consider cost a secondary priority to performance, so am definitely willing to work with more expensive parts and tubes if this will give me greater fidelity and build something I will be happy with for a very long time.
In an ideal world I would be pointed to something like the equivalent of a First Watt illustrated build guide type of build instruction, with references to specific components and parts, where they can be sourced, and some general guidance wiring it all up. It looks like this was wishful thinking and I am sure I will manage with just a circuit schematic. With the FW amps it is just so easy to dive right in, with tubes it looks like a lot more homework is required. Thanks again.
One thing is for certain, it is not a straightforward as I had thought. The rabbit hole goes deep in the world of tubes (which I like - a lot to learn). There are countless options out there, and I guess a starting point would be to determine which output transformer and tube to go with. 2A3 or 300B seem to be the lead candidates. A lot I need to go research but thanks for putting me on the right path.
To answer some of the questions re clarification what I am looking for. As JZatopa put it: "the most competently designed SET amplifier design that has been ever designed with respects to all aspects of amplifier performance" is a nice way to describe it (however likely a lot of debate what this might mean). Other than this, and a general need for around 4 watts of more (I am running 95dB speakers), I don't really know what I need, am pretty much open to anything. And to answer another poster's question, I do not share the 2$ mentality when it comes to building amps, I consider cost a secondary priority to performance, so am definitely willing to work with more expensive parts and tubes if this will give me greater fidelity and build something I will be happy with for a very long time.
In an ideal world I would be pointed to something like the equivalent of a First Watt illustrated build guide type of build instruction, with references to specific components and parts, where they can be sourced, and some general guidance wiring it all up. It looks like this was wishful thinking and I am sure I will manage with just a circuit schematic. With the FW amps it is just so easy to dive right in, with tubes it looks like a lot more homework is required. Thanks again.

I´ve a KT88 amplifier design. You have to wire the audio input, the audio outputs, the 230VAC main supply, two chokes (Hammond = cheap) and the toroidal main and OT (from Toroidy = cheap); all other components on PCB. Unity shot = 600€ (KT88 paired and selected, dito for 6922 from Tube Amp Doctor Germany).
I´ve started the 4P1L it is ongoing...
Another one is the direct coupled 2A3 with the Belgium MONOLITH Magnetics OT: I can supply complete EAGLE job. Unity shot with best parts = 1000€.
I´ve started the 4P1L it is ongoing...
Another one is the direct coupled 2A3 with the Belgium MONOLITH Magnetics OT: I can supply complete EAGLE job. Unity shot with best parts = 1000€.
Attachments
In an ideal world I would be pointed to something like the equivalent of a First Watt illustrated build guide type of build instruction, with references to specific components and parts, where they can be sourced, and some general guidance wiring it all up. It looks like this was wishful thinking and I am sure I will manage with just a circuit schematic. With the FW amps it is just so easy to dive right in, with tubes it looks like a lot more homework is required. Thanks again.
[/QUOTE]
Tubelab | Dedicated to advancing the state of the art in affordable high end audio.
This link has very detailed builds of tube projects and is a respected member of this forum. Much like 6L6's builds.

Tubelab | Dedicated to advancing the state of the art in affordable high end audio.
This link has very detailed builds of tube projects and is a respected member of this forum. Much like 6L6's builds.
audioexplorations, 95dB speakers sounds promising but this number does not fully guarantee that they will play to your satisfaction on a very low powered amp.
You could tell us what they are and maybe somebody has direct experience, but otherwise this is hard to know without trying it out.
You could give me impedance plots, schematics of the crossovers, and pictures of the designers wife and kids, and I'd still be guessing whether they are a good match for a 4 watt amp or not.
The best thing you could do is stock up on beer and invite somebody over with a similar amp for testing with your speakers before you invest. If this impossible, I would spend the extra money on a 300B amp or whatever it takes to get up to 8-10W for extra security.
This area of audio is indeed, as you put it, a rabbit hole, and it goes far beyond your imagination.
Many who have taken this path work the other way, start with the amps and then find speakers that are optimal for the chosen class of amps.
You are not proposing to build only an amp, you are working on a SYSTEM.
You could tell us what they are and maybe somebody has direct experience, but otherwise this is hard to know without trying it out.
You could give me impedance plots, schematics of the crossovers, and pictures of the designers wife and kids, and I'd still be guessing whether they are a good match for a 4 watt amp or not.
The best thing you could do is stock up on beer and invite somebody over with a similar amp for testing with your speakers before you invest. If this impossible, I would spend the extra money on a 300B amp or whatever it takes to get up to 8-10W for extra security.
This area of audio is indeed, as you put it, a rabbit hole, and it goes far beyond your imagination.
Many who have taken this path work the other way, start with the amps and then find speakers that are optimal for the chosen class of amps.
You are not proposing to build only an amp, you are working on a SYSTEM.
Many who have taken this path work the other way, start with the amps and then find speakers that are optimal for the chosen class of amps.
You are not proposing to build only an amp, you are working on a SYSTEM.
Working on a system is the essential point. That's why I would always propose to decide on speakers first, as they are the most sound shaping (or the most horrible and non-linear devices in the chain...) and then build amplifiers that are able to deal with your speakers. If it's gonna be a tube amp start with the second most horrible part in the chain, the output transformer and then work from there.
Joe - see this thread for the full details on my speakers.
That thread led me to build the Nelson Pass ACA amps which are 6 watts/ch, and these are absolutely rocking them with seemingly unlimited reserves of power, even on heavy hitting bass driven music. Current project is an F6, after which I will start the SET project.
I have always understood that you should start with the speakers and then mate with the right amp. Reason being is that the right speaker is determined by the size of the room and placement constraints. Proximity to boundaries and getting woofers away from room modes so they are not excited to avoid overpowering the room.
That thread led me to build the Nelson Pass ACA amps which are 6 watts/ch, and these are absolutely rocking them with seemingly unlimited reserves of power, even on heavy hitting bass driven music. Current project is an F6, after which I will start the SET project.
I have always understood that you should start with the speakers and then mate with the right amp. Reason being is that the right speaker is determined by the size of the room and placement constraints. Proximity to boundaries and getting woofers away from room modes so they are not excited to avoid overpowering the room.
There is no one way to approach the project of system building.
I know I like low medium tube amps, so I'm not buying or building anything that needs 100W.
I don't agree with your boundary arguments as a general principle. Depends on the specific case. I even use Western Electric wall speakers designed to be mounted ON the wall (but I have them on stands near the wall.) Sealed box speakers can use those boundaries for bass reinforcement to the benefit of the system. Really, it depends on specific cases.
That speakers looks like the right stuff. If you are already running 6W SS with success that is a good sign. I will caution you that to get amazing bass slam from a low-powered SE amp is no small matter and among a list of considerations, very high demands are placed on speaker selection.
Your future 2A3 or 300B will perhaps be better suited to jazz and classical than headbang techno...unless you like very organic sounding techno!😀
I know I like low medium tube amps, so I'm not buying or building anything that needs 100W.
I don't agree with your boundary arguments as a general principle. Depends on the specific case. I even use Western Electric wall speakers designed to be mounted ON the wall (but I have them on stands near the wall.) Sealed box speakers can use those boundaries for bass reinforcement to the benefit of the system. Really, it depends on specific cases.
That speakers looks like the right stuff. If you are already running 6W SS with success that is a good sign. I will caution you that to get amazing bass slam from a low-powered SE amp is no small matter and among a list of considerations, very high demands are placed on speaker selection.
Your future 2A3 or 300B will perhaps be better suited to jazz and classical than headbang techno...unless you like very organic sounding techno!😀
You are missing the point. You said,That's one test. not generalizable to all cases, which is the absurd claim you were making above about ALL "amps measuring the same sounding the same"
and I proved you wrong.you have not in fact tested your assertions and you are speaking from belief.
BTW, this is what I said.
You added the word "ALL". Very deceptive of you.So you are saying that amps that measure the same sound the same.
Yes. Also, amps that measure differently can also sound the same to listeners. Why? That's because today's audio measuring devices can detect far beyond what people can hear.

You sound a lot like Robert Harley, editor-in-chief of The Absolute Sound magazine who makes money from selling advertisement spots for overpriced audio electronic devices. In doing so, he has to spread the belief that those overpriced audio electronic devices sound better than cheaper ones however, one big roadblock against his attempt is double blind test. So, what does he do? He tries to discredit double blind test with all sorts of erroneous claims.Double blind testing is totally flawed. I can go into it in enormous, encyclopedic detail but first let me know your educational level and qualifications to evaluate human research design.
I have two Ivy League degrees in this subject and did two PhD programs in relevant material and I can assure you that only rubes who do not understand the topic fully make strong claims about double-blind testing.
Now why are you trying to discredit double blind test? Oh, wait, this explains.
I'm in the audio business.
Forum members, we have ourselves a shill here trying to boost his business.
Off topic. You can start your own thread.Lets hear about your actual experience with SE amps, measurements, and correlations between the two.
Today's audio measuring technology can measure and show everything we can hear and beyond. What more development do you think is needed?The interpretations of the measured quantities, measurement methods, and list of quantifiable items to measure, however, are still being investigated. My opinion is that the measurement art is still in the development stage, critics are the prerequisites to to a new level of understanding. Engineers left out (what the consensus at the time thought as) irrelevant data which at a later time were found to be quite significant. I do not suppose that everybody is happy and wish for the art to stagnate, even those saying tests are flawed.
Moreover, different people hear differently; some people are trained musicians, some partially tone deaf and others are totally deaf. I must admit that I was trained as a musician during junior and highschool years but currently one of the partially tone deaf, I can no longer hear 14kHz and above sinusoidal tone. So when I say 2 systems sound similar does not mean others will agree. But I still enjoy and tweak my "continuously under development" system.
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