Watts Up...?
Dec 22, 2021 at 6:13 AM Post #2,896 of 4,753
. . . guitar amps, old keyboards . . .
Just listen to the music!
most of 70's Rock has hiss, hum, bump and occasional coughs and farts - never bothered me.
Most classical music . . I wouldn't even start on them.
I am not bothered by hiss that much. An obvious hum by an open input for example I find very annoying.
But my post was all meant as a joke regarding the video I found very interesting. But of course I still hoped Rob could give insights into the quality of his filtering in that regard, because it seems in the video like it is very common for most devices/recordings to have some artifacts like that. For people who don’t want to watch the video: Investigators know when exactly something was recorded if they have history of mains frequency fluctuations by comparing it to the mains hum in the recording. I find that astonishing that they have convicted criminals by that technique. I just thought I put it in a funny context, so enjoy your classic recordings😎
 
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Dec 24, 2021 at 4:31 AM Post #2,897 of 4,753
The crazy thing about listening tests is that errors that are effectively zero are still audible - even today, after 40 years of designing gear, I am constantly being surprised at how sensitive the ear/brain actually is. And of course I can hear the sceptic saying it's all placebo; and sure placebo is a powerful thing, but I spend a lot of time minimizing placebo and other biases from my listening tests - and when I get extraordinary results I run blind tests with my son - and the extraordinary results still stands.

On one hand I am delighted that I am so sensitive to minute changes - as otherwise progress could not be made. But life would be so much easier if I could detect no difference from live unamplified sound to reproduced sound. But then how could one enjoy music without sensitivity?
Just a question about the resurgence of Vinyl media, I can’t understand that it’s anything to do with sound quality when the Vinyl pressing is made from a digital master, but for earlier releases that were recorded/mixed/mastered with analogue equipment, and given the chain it has to go though, master tape through RIAA EQ, cutter head, master to stamper discs, then back through the cartridge and RIAA EQ again, resulting in the inevitable loss of transparency, are the transients amongst others still more accurately reproduced than a reconstituted digital signal,
And maybe why there’s still those willing to trade losses in some areas with Vinyl reproduction ?
 
Dec 24, 2021 at 6:23 AM Post #2,898 of 4,753
Vinyl perhaps out performs MP3 on a mobile phone, or against an inexpensive CD player; together with fashion, this helps explain its resurgence.

But compared to my system it just sounds soft, distorted and lacking in transparency - there being no benefits to me at all. Some however like unnatural, soft ill defined bass though.

My two boys have taken up music in a big way - we have 8 acoustic and electric guitars now, and my wife bought a second hand Welmar piano, which used to belong to a musician in the Welsh National Opera. It was installed today - and sounds fantastic. Also arriving this morning (Christmas Eve) was the next prototypes for the pulse array ADC - so I will have a busy time over Christmas and early next year - hopefully trying to close the large gap from live unamplified sound to reproduced sound.

Wishing you all a very happy Christmas and New Year,

Happy listening, Rob
 
Dec 24, 2021 at 6:34 AM Post #2,899 of 4,753
Vinyl perhaps out performs MP3 on a mobile phone, or against an inexpensive CD player; together with fashion, this helps explain its resurgence.

But compared to my system it just sounds soft, distorted and lacking in transparency - there being no benefits to me at all. Some however like unnatural, soft ill defined bass though.

My two boys have taken up music in a big way - we have 8 acoustic and electric guitars now, and my wife bought a second hand Welmar piano, which used to belong to a musician in the Welsh National Opera. It was installed today - and sounds fantastic. Also arriving this morning (Christmas Eve) was the next prototypes for the pulse array ADC - so I will have a busy time over Christmas and early next year - hopefully trying to close the large gap from live unamplified sound to reproduced sound.

Wishing you all a very happy Christmas and New Year,

Happy listening, Rob
2.5 hours to go here,
Merry Christmas and a happy new year from “down under” , enjoy the break, relax and recharge the batteries ..
 
Dec 24, 2021 at 2:04 PM Post #2,900 of 4,753
Happy holidays to everyone.
I have a question:
I recently tried a new headphone cable with confusing results.
The headphones are Magnetic planars with constant impedance over the frequency.
The cable in question is a solid core pure silver type with two conductors per side, plaited together, nothing special.
I measure the cable, its resistance is on a par with bundled cable that comes with Focal Clear (about 0.15R per conductor) , again nothing spectacular.
Its capacitance though is low, very low, less than 5pF that my meter can measure (an LCR meter), inductance is also below threshold.
Focal cable capacitance is about 70pF per side (lead to ground), also with negligible inductance, so the main difference is capacitance.
Other cables I measured were in 200pF range.
The question:
The effect the cable has on my Mojo is that it sounds brighter! in a good way.
On Hugo2 the effect is the reverse, it makes Hugo2 less bright, indeed on less than perfect recordings, the glare is gone.
That is on three headphones, two Hifiman and also tried it on Focal Clear.
Is there anything on Mojo and/or Hugo2 output section that is sensitive to capacitive loads??
The only difference between this cable to others is mainly capacitance.
 
Dec 24, 2021 at 11:34 PM Post #2,901 of 4,753
Interesting. Both Mojo's and Hugo 2's OP stages drive internal capacitors, which are many times larger than the cable capacitance, so I don't think it's that.

Changing to solid core does two things - brighter tonal balance (due to improved transparency) plus reduced grain and hardness (due to the reduction in HF distortions due to skin effect and surface oxides) - this makes it sound warmer. So you have two effects going on when going to solid core - one making it brighter, one making it warmer.

Which effect wins out will depend upon the whole chain. Also, Hugo 2 is much more accurate and revealing, Mojo (by intent) puts a rose tinted view on things. So I guess improvements in treble grain will be more apparent with Hugo 2, thus making the warmth win out.
 
Dec 25, 2021 at 5:56 AM Post #2,902 of 4,753
Just a question about the resurgence of Vinyl media, I can’t understand that it’s anything to do with sound quality when the Vinyl pressing is made from a digital master, but for earlier releases that were recorded/mixed/mastered with analogue equipment, and given the chain it has to go though, master tape through RIAA EQ, cutter head, master to stamper discs, then back through the cartridge and RIAA EQ again, resulting in the inevitable loss of transparency, are the transients amongst others still more accurately reproduced than a reconstituted digital signal,
And maybe why there’s still those willing to trade losses in some areas with Vinyl reproduction ?
You're over thinking it. You just have to listen to vinyl to realise that there's something MAGIC there and that there is still something important missing from digital replay.
 
Dec 25, 2021 at 6:54 AM Post #2,903 of 4,753
Interesting. Both Mojo's and Hugo 2's OP stages drive internal capacitors, which are many times larger than the cable capacitance, so I don't think it's that.

Changing to solid core does two things - brighter tonal balance (due to improved transparency) plus reduced grain and hardness (due to the reduction in HF distortions due to skin effect and surface oxides) - this makes it sound warmer. So you have two effects going on when going to solid core - one making it brighter, one making it warmer.

Which effect wins out will depend upon the whole chain. Also, Hugo 2 is much more accurate and revealing, Mojo (by intent) puts a rose tinted view on things. So I guess improvements in treble grain will be more apparent with Hugo 2, thus making the warmth win out.
And on Xmas day, still on duty!
thank you, my hats off to you.
 
Dec 25, 2021 at 8:55 AM Post #2,905 of 4,753
You're over thinking it. You just have to listen to vinyl to realise that there's something MAGIC there and that there is still something important missing from digital replay.
I agree with some recordings, and with Vinyl purchased from the analogue recording/ production days the vast majority have that “something” or rather early digital had “something missing” as well as a hard grainy edge from early digital hardware that was fatiguing for extended listening, some early CD’s from the 80’s are noticeably inferior where a recent “ remaster” on more modern equipment can sound a lot better ….
 
Dec 27, 2021 at 10:51 AM Post #2,906 of 4,753
Vinyl perhaps out performs MP3 on a mobile phone, or against an inexpensive CD player; together with fashion, this helps explain its resurgence.

But compared to my system it just sounds soft, distorted and lacking in transparency - there being no benefits to me at all. Some however like unnatural, soft ill defined bass though.

My two boys have taken up music in a big way - we have 8 acoustic and electric guitars now, and my wife bought a second hand Welmar piano, which used to belong to a musician in the Welsh National Opera. It was installed today - and sounds fantastic. Also arriving this morning (Christmas Eve) was the next prototypes for the pulse array ADC - so I will have a busy time over Christmas and early next year - hopefully trying to close the large gap from live unamplified sound to reproduced sound.

Wishing you all a very happy Christmas and New Year,

Happy listening, Rob
Hi Rob,

I recently listened to a talk you gave at RMAF 2017. Have to say that as a neuroscientist myself, it is quite refreshing to hear someone in the HiFi audio industry emphasize psychoacoustics and the neurobiology of sound perception. It is incredible how little we know about how the brain perform the computations that allow us to experience sound the way we do. I absolutely share you passion/fascination in this topic. Btw, I recently got a Hugo 1 and I am amazed with what it did in my system (RPi4 streaming Qobuz --> Hugo --> McIntosh MA252 hybrid integrated amp --> Totem Forest speakers + KEF KC62 subwoofer). Can't wait to try Chord DACs with larger filter taps in the future!

Happy New Year!
Mario P.

 
Dec 27, 2021 at 11:31 AM Post #2,907 of 4,753
Be interesting to hear your views and opinions from you’re chosen field, all too often scientific research is mutually exclusive and looking into other scientific fields can result in unexpected breakthroughs …
From the audio engineering/ science point of view, with high tech measuring equipment it’s possible to measure down to “inaudible” differences, but without truely knowing what the threshold of inaudibility is, what the ear “hears” and transmits to the brain and what the brain does with the information may mean that the whole auditory system is far more critical than what is regarded as “inaudible” and why there is still a gap between live and recorded sound ?
 
Dec 27, 2021 at 12:23 PM Post #2,908 of 4,753
Absolutely. We are still learning of how sensory systems give rise to perception. Take the retina as an example. Classical research led to the view that the visual system is divided into retinal cells of two different categories based on molecular features: one that affect conscious perception, and one that participates non-image forming functions (circadian photoentraintment). Contrary to this view, research in the last decade demonstrated that the so called non-image forming pathway actually influences vision (e.g. contrast).

Unlike the visual system where the spatial distribution of sensory information is already mapped at the level of the sensory organ (retina), basic auditory information such as the location of sound sources in space are not generate in the ear (cochlea) but actually by computations performed by the brain itself. As Rob mentioned in his lecture, the brain computes things like the inter-aural time and level differences (ITD and ILD) and relies on spectral filtering at the level of the pinna to determine the location of sounds in space. I think that a combination of psychoacoustics and neuroscience research is our best bet to determine what are the elements of sound that the brain uses to perform these computations.
 
Dec 28, 2021 at 7:37 AM Post #2,909 of 4,753
One of the most fascinating things is that with IEMs in place, providing about 25dB of attenuation (obviously varies with frequency), direction and depth perception isn't affected.
 
Dec 28, 2021 at 4:02 PM Post #2,910 of 4,753
Absolutely. We are still learning of how sensory systems give rise to perception. Take the retina as an example. Classical research led to the view that the visual system is divided into retinal cells of two different categories based on molecular features: one that affect conscious perception, and one that participates non-image forming functions (circadian photoentraintment). Contrary to this view, research in the last decade demonstrated that the so called non-image forming pathway actually influences vision (e.g. contrast).

Unlike the visual system where the spatial distribution of sensory information is already mapped at the level of the sensory organ (retina), basic auditory information such as the location of sound sources in space are not generate in the ear (cochlea) but actually by computations performed by the brain itself. As Rob mentioned in his lecture, the brain computes things like the inter-aural time and level differences (ITD and ILD) and relies on spectral filtering at the level of the pinna to determine the location of sounds in space. I think that a combination of psychoacoustics and neuroscience research is our best bet to determine what are the elements of sound that the brain uses to perform these computations.
I seem to remember reading that the eye adjusts the lens focus 300 times a second (although humans are unaware of this on a concious level).
Does the ear/brain system perform a similar check/reset many times a second? Just thinking that it may influence how the ear/brain can rapidly detect transients.
 

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