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Integrated Amplifier Comparison: $90 vs $9000

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If we look at the aligned spectra, which is the comparison *after* DeltaWave has done its level/phase adjustments, the white (FOSI V3) does have more content below 30 Hz than the blue (Marantz PM-10).

View attachment 302349
The 4th figure/aligned spectra seems like a sweep comparison to me and I am not experienced. Is there not a chart that moves along the time domain for 3 minutes.
 
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In the end, I concluded that one of the amplifiers had some issues with the more difficult load presented by the Utopias. That's not a conclusion I would fight for though. It just had the practical consequence that I changed my amps/speakers pairing.
Which means amplifiers sound different with different speakers and gear matching is a thing
 
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If people are dismissing properly controlled and carefully executed listening impressions that is a real problem.

But uncontrolled and sighted listening impressions don't bring any useful information to the discussion. They don't mean anything to anyone other than the subjectivist who listened. In these cases, the main problem comes when people accept uncontrolled listening impression as valid data - that just takes everyone off down a rabbit hole.
People listening to music is uncontrolled listening impressions. Billions of people who ever heard a song do that. We as humans understand music more subtly and complexly that you would give them credit for. If you are going to dismiss the listening skills of people about audio equipment, you are also dismissing the auditory skills in general of the human race. I don’t agree with you at all. Centuries long music traditions have been created without precise matching and measurements and the music produced is wonderfully nuanced in almost every culture.
 
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GXAlan

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The 4th figure/aligned spectra seems like a sweep comparison to me and I am not experienced. Is there not a chart that moves along the time domain for 3 minutes.

I only compared the first 35 seconds or so. The PK Metric is the best one at answering that comparison since it is comparing along the time domain with a perceptually weighted comparison between the two recordings


The other charts that look at time domain are ones like this
1698598718704.png

1698598735491.png


Which are much harder to interpret than the PK Metric.

@pkane

has set -50 dB as a reasonable threshold for "hard to tell the difference" versus "easily can tell the difference." Since one number cannot represent everything and everyone, if you wanted to be very strict, some PK Metric's as low as -80 dB can be audible although I'd put it closer to -70 dB with acoustic measurements

Which means amplifiers sound different with different speakers and gear matching is a thing

I think the key is that some amplifiers sound different for a given speaker. But more important than saying that gear matching is a thing (which I agree with), the level of gear matching can be measured objectively* (in terms of differences, not necessarily preferences).
 

antcollinet

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People listening to music is uncontrolled listening impressions. Billions of people who ever heard a song do that. We as humans understand music more subtly and complexly that you would give them credit for. If you are going to dismiss the listening skills of people about audio equipment, you are also dismissing the auditory skills in general of the human race. I don’t agree with you at all. Centuries long music traditions have been created without precise matching and measurements and the music produced is wonderfully nuanced in almost every culture.
Sure but we don't need to be able to precisely and acccruately compare two different sources of sound for any of that - and what we hear is influenced by cognitive biases. These are unavoidable - it is the way we are built. Indeed without this prefiltering of our senses we would be unable to function. And we can't "decide" not to be subject to them.

What that means is that - even though we are able to hear lots of stuff, appreciate all the subtlety and drama of music and so on - our biases can cause us to hear things that are different even when they are not - based on our subconsious expectations, based on what we see, how we feel, any substances we have imbibed etc etc. That means when you (or anyone else) tells me they hear something different from two pieces of kit, I don't know if that is real, or if it is a restult of your subconcious biases. IE, no information. Unless you have controlled to eliminate those biases, such as blind listening.

Further - if the measurements of two devices tells me the performance is so close that differences will be so small as to be inaudible, I am going to be fairly certain that what you are hearing is not in the sound-waves hitting your ears, but created in the wetware between them.
 
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Screenshot 2023-10-29 213558.png
PC DAC chip > Schiit Ragnarok 2

Vs

Cambridge CXA81 on its own

Level matched with multimeter to 0.7 volts
Same speakers in both, KEF Q550


Make sense of it please
 
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GXAlan

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PC DAC chip > Schiit Ragnarok 2
Vs
Cambridge CXA81 on its own

Level matched with multimeter to 0.7 volts
Same speakers in both, KEF Q550

Make sense of it please

Instead of just doing a sweep, go ahead and record two pieces of music. Using Audacity, trim the front of the clip so that relatively closely match.

Then download DeltaWave https://deltaw.org/ and you can get a lot of information quickly where the last bit of level matching is done digitally...
 

Geert

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View attachment 322287PC DAC chip > Schiit Ragnarok 2

Vs

Cambridge CXA81 on its own
Level matched with multimeter to 0.7 volts
Same speakers in both, KEF Q550
Make sense of it please

Why is there so much difference in the low end, where the different resonances we see are caused by room acoustics and speaker and listening position?

Screenshot_20231029_224208_com.android.chrome.jpg


And what about the differences in the highs in the thumbnails that are not visible in the large graph?
 
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MaxwellsEq

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Measurements
After my subjective impressions, I decided to try something new. I moved my UMIK-2 back to the listening position and recorded the first 3 minutes of Hotel California on each system. A 48 kHz sampling rate was used. I then brought the recordings into @pkane 's DeltaWave for analysis.
DeltaWave shows that my volume matching was as good as it gets. 0.05 dB difference in RMS. Deltawave corrects this to 0.007 dB.
Initial RMS values Reference: -29.814dB Comparison: -29.761dB
Personally, I think this methodology is a bit flawed. In the same circumstances, I would have level-matched using a voltmeter to 0.01V accuracy at 1kHz. After that I think you can validly use DeltaWave.

My rationale is:
1) we know from multiple experiments that electronics sound differences frequently disappear when levels are matched precisely.
2) even the slightest differences in energy at the speakers will affect cabinet, driver and room interactions.

I believe that things can not be described as level matched unless a voltmeter is used and the volts are the same.
 
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GXAlan

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Personally, I think this methodology is a bit flawed. In the same circumstances, I would have level-matched using a voltmeter to 0.01V accuracy at 1kHz.
Sigh. You should try what you are suggesting…

Let’s compare 1V vs 1.01V into 6 ohms. That should translate into 77.964 vs 78.050 dB. So my matching is BETTER than 0.01V.

After that I think you can validly use DeltaWave.

My rationale is:
1) we know from multiple experiments that electronics sound differences frequently disappear when levels are matched precisely.
2) even the slightest differences in energy at the speakers will affect cabinet, driver and room interactions.

I believe that things can not be described as level matched unless a voltmeter is used and the volts are the same.
Yes, and I have better than 0.01V matching done with the Fosi’s not particularly dampened analog volume knob.
 

PierreV

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Which means amplifiers sound different with different speakers and gear matching is a thing
In that particular case, I believe the Utopias had a higher current demand than the Giyas in a lowish frequency range. One amp was able to deliver, the other was not. I wouldn't generalize my specific experience though as I don't know either how frequent "hard-to-drive" speakers are or how many amps are so current-limited when the impedance/phase is unfavorable that the difference becomes audible.
 

Galliardist

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But the difference would still be indicative of what might happen to the sound, like one amp might sound brighter than the other. The magnitude of the audible difference might not be obvious, but that's still a different story than "tells you absolutely nothing".



Don't know where 'better' entered the discussion. 'Better' is subjective. Does a microphone measurement shows what sounds better, and also above the Schroeder frequency (since you found differences in what you called the 'vocal region')?
Clearly you confused me with someone else as you were replying to my first post in this thread: I’ve reported nothing.

Better: closer to an ideal. That ideal need not be a subjective one at all - "straight wire with gain" as a target suggests that the output should be a simple amplification of the input.
 

Galliardist

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Which means amplifiers sound different with different speakers and gear matching is a thing
Yes - but the differences should be definable according to objective principles and measurements. We don't have to enter the mug's game of continually swapping in different amplifiers and speakers until we accidentally hit on what we subjectively prefer that day.
People listening to music is uncontrolled listening impressions. Billions of people who ever heard a song do that. We as humans understand music more subtly and complexly that you would give them credit for. If you are going to dismiss the listening skills of people about audio equipment, you are also dismissing the auditory skills in general of the human race. I don’t agree with you at all. Centuries long music traditions have been created without precise matching and measurements and the music produced is wonderfully nuanced in almost every culture.
With the greatest respect, this comment is terrible.

Music has evolved through the design of instruments and playing techniques, and the underlying principles of pitch and harmony, to be understood by humans. It matches our auditory skills, accordingly.

When it comes to a reproduction system though, there are two interrelated principles you don't seem to get. The first is that a reproduction system is not another musician. It should not contribute to the music so that we tell the difference that way: its job is to, ahem, reproduce. The music is the job of the musicians.

Secondly, and as a result, reproduction systems have to be judged in a different way to a musical instrument, and that part of the process is not something that humans are particularly well set up to do. So we can recognise patterns, pitch, voice inflection, and rhythm, but we don't do so well on tonality of instruments (it's a lot easier to tell two musicians apart, than the same professional musician playing two different, well made acoustic instruments), we don't get stereo imaging as well as we think: but we are incredibly confident we can tell these differences, and our brains when dealing with two sounds that are "supposed to be different" call upon sight, memory and anything else the brain has available to sort out what it is hearing.

The other thing to remember is that we don't need hi-fi to distinguish most or all of those "subtle features" in music you refer to. People do this with all those cheap earbuds and smart speakers and soundbars and all the other stuff we audiophiles tend to look down on. In fact, the hardest class of listening equipment to do this with is a poorly matched and set up full range stereo system. Too often we actually do damage.

Far from dismissing the auditory skills of humans, we recognise those skills in both their strengths and deficiencies. You would do well to understand this.
 

ahofer

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People listening to music is uncontrolled listening impressions. Billions of people who ever heard a song do that. We as humans understand music more subtly and complexly that you would give them credit for. If you are going to dismiss the listening skills of people about audio equipment, you are also dismissing the auditory skills in general of the human race. I don’t agree with you at all. Centuries long music traditions have been created without precise matching and measurements and the music produced is wonderfully nuanced in almost every culture.
Do not confuse what we know about equipment and sound waves with what we may not know about hearing auditory perception and how music affects people. These are very different things. We have yet to come up with a strictly audible phenomenon that isn't measurable. Including the room, which makes a lot more difference than an amp.

The more chaotic stuff happens inside the listener's brain in conjunction with other senses.

Performance of audio equipment has nothing at all to do with centuries of music traditions and nuance. Connecting them is hand-waving designed to move overpriced high-end gear.
 

Geert

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Clearly you confused me with someone else as you were replying to my first post in this thread: I’ve reported nothing.

Indeed, my bad. You almost have the same avator as the OP, who reported the largest differences in the vocal region.
 

MaxwellsEq

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Yes, and I have better than 0.01V matching done with the Fosi’s not particularly dampened analog volume knob.
You set the gain to max and vary the signal source.
 

antcollinet

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You set the gain to max and vary the signal source.
I think with most of these chip amps, the volume pot simply attenuates the input signal. This is equivalent to turning down the source signal, so should be fine.
 

MaxwellsEq

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I think with most of these chip amps, the volume pot simply attenuates the input signal. This is equivalent to turning down the source signal, so should be fine.
I agree but @GXAlan pointed out the difficulty of signal level matching with wobbly pots.
 

antcollinet

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I agree but @GXAlan pointed out the difficulty of signal level matching with wobbly pots.
Sorry misunderstood. But either you're going to have wobbly pots or you are going to have a digital control which probably only gives you half a DB of resolution.
 
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Performance of audio equipment has nothing at all to do with centuries of music traditions and nuance. Connecting them is hand-waving designed to move overpriced high-end gear.
You cannot remove the human element out of both and thats what connects them. You cannot say that humans can create sophisticated music using their auditory skills but they cannot use those skills to judge audio equipment. When they clearly use those skills to judge different instruments. Its not about music affecting people, its about people evaluating music/sounds. I think you are vastly overvaluing few limited measurement techniques and using them to dismiss people’s auditory perception.
 
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