Might it be as simple as the speakers being muted during the ADC-DAC process but (of course) not during direct playback? I have yet to hear a turntable that doesn't pick up significant feedback from the speakers.
Playback is in realtime in both cases, A/D-D/A is instantly while the turntable is playing.
See posting 1011.
Hans
Hi Peter,
It is the Gibbs phenomenom.
In many publications one can find that post echo's are harmless but pre echo's can be perceived as negatively.
https://en.wikipedia.org/wiki/Ringing_artifacts
And under pre echo's
https://en.wikipedia.org/wiki/Pre-echo
Also have a look at Fig1 and Fig2 in this stereophile test, showing first a response as most DAC's have with a brick wall linear phase filter, but also a response without pre-ringing from a Meridian player with an apodizing filter.
Meridian 808.2/808i.2 Signature Reference CD player/preamplifier Measurements | Stereophile.com
Playing a downsampled 16/44.1kHz CD, this meridian player could hardly be discerned from an Ayre player having a Brick wall filter playing the original file in 24/96kHz
At a later stage, Ayre implemented their own version of apodizing filter with less ringing for their highly praised QB-9 DAC.
Ayre Acoustics QB-9 USB DAC Measurements | Stereophile.com
Many investigations are trying to assess the eventual advantages of eliminating pre ringing, like below, but also in the reference list of this article.
http://audio-life.nl/sites/default/files/brochures/ps-audio-aes-white-paper.pdf
So to conclude, I'm not alone in suspecting the pre-ringing of digital filters.
Hans
Hi Jan,
Thanmks for your comments. To my understanding, Gibbs phenomenon has nothing to do with filters per se. It is a phenomenon that occurs regardless of the number of harmonics that are used to mathematically construct a square wave, especially when the number of harmonics is large. Please see "The square wave example" (No.4 in the Content list) in the link I posted. You'll see that the amplitude and damping of the overshoot does not change as the harmonics increase, unlike what would occur when a steep sloped LP filter is used.
Peter
Thanmks for your comments. To my understanding, Gibbs phenomenon has nothing to do with filters per se. It is a phenomenon that occurs regardless of the number of harmonics that are used to mathematically construct a square wave, especially when the number of harmonics is large. Please see "The square wave example" (No.4 in the Content list) in the link I posted. You'll see that the amplitude and damping of the overshoot does not change as the harmonics increase, unlike what would occur when a steep sloped LP filter is used.
Peter
That's part of it. The other part is the details on the setup of the listening test.
Sorry Jan,
I was still writing while you already posted just before me.
It was not my intention to discredit you with this Gibbs thing.
Hans
No, I meant linear filter i.e. a filter which does not create any new frequency components but merely changes the amplitude and phase of the components in the input signal.Hans Polak said:
A linear filter has no products. There is no signal at 96kHz. What you see is the effect of filtering alone on the components from the input square wave, some of which will be in the vicinity of 96kHz and when phase-shifted etc. may give the superficial appearance of some new signal at 96kHz. There is no 'mingling' if the filter is linear.
I was warning newbies not to be alarmed when they see 'ringing' caused by sharp filters. You can get rid of them by using softer filters, but then you have to choose between throwing away some signal (which you could have included) or accepting some aliasing.
True, but was such a filter used in this case? I repeat, the aim of digital audio is to exactly reproduce the signal which emerges from the anti-aliasing filter. If you put a square wave into an anti-aliasing filter you are likely to see 'ringing' on the output. I'm sure you realise that this is not anything added, but the result of what has been subtracted. If you then pass this signal through an ADC+DAC+reconstruction filter you will see the same 'ringing' on the output; fidelity requires this!
It is just possible (but only just!) that removing the Sinc frequency response could be audible, as this is likely to do some phase shifting too.
I'm sorry, but my feeling is that our conversation will not lead to a further understanding why in the simple test with an inline added A/D-D/A while playing an analogue recorded LP, the perceived sound is affected negatively.
And that a CD recorded by Stereoplay from the same LP material, sounds almost identical to my A/D-D/A processed version giving extra confirmation on the validity of my own test.
These tests all being performed as an attempt to understanding "as to why some prefer vinyl".
I'm sure I'm not the only one in the world with the Kind of Blue LP or any one of the other 13 recordings on the CD.
And most owners of Record Players will also have CD players.
A copy of Stereoplay with it's CD is relatively easy to locate, so who else can do the same test and compare the directly recorded CD from the LP to the LP itself and report his findings here.
It would be interesting to hear your experiences.
Hans
How were the listening tests done though..... Sighted?
I have said numerous times on this thread I love LP playback, I also love playback from my hard drive with my digital stuff, I don't hear any problems with digital playback but I do with LP. So I don't worry just listen to the music....
Yet still many are hell bent on proving against the odds how bad digital is.... Someone did a test (blind) it may have been Pano (he has done some good tests that if nothing else proved that many did not have super human hearing and un sighted the differences just disappear) were a similar thing was done and no body noticed because they couldn't see the a to d...
Now what about music recorded and stored in the digital domain before its put on to a record (or a CD).
I have said numerous times on this thread I love LP playback, I also love playback from my hard drive with my digital stuff, I don't hear any problems with digital playback but I do with LP. So I don't worry just listen to the music....
Yet still many are hell bent on proving against the odds how bad digital is.... Someone did a test (blind) it may have been Pano (he has done some good tests that if nothing else proved that many did not have super human hearing and un sighted the differences just disappear) were a similar thing was done and no body noticed because they couldn't see the a to d...
Now what about music recorded and stored in the digital domain before its put on to a record (or a CD).
So you do your listening tests sighted...
A listening test is NOT listening to music for relaxation, you are trying to discern a difference, it is a TEST...
A listening test is NOT listening to music for relaxation, you are trying to discern a difference, it is a TEST...
So do I
The same
That may be the case, but it is not relevant in this thread.
The simple question is "as to why some prefer vinyl" and not "why is digital so bad". Preferring one over the other, if one has the choice, does in no way means anything else but just that.
That's a very good question. To start with I have looked at analogue recordings free from any digital processing.
As you know I have put an A/D -D/A in line while playing, and did not expect to hear any difference at all. This would have stopped for me the whole further discussion.
But to my great surprise the difference was so obvious, that I had to revise my opinion on LP's.
The other surprise was that my digitized version sounded so similar to the Stereoplay CD recording.
My current expectation is that the difference with digitally recorded LP will be much smaller when performing this test with an added A/D-D/A, but you never now and preoccupation should be avoided.
Hans
Just to throw some gas on the fire 😉
I thought this one was funny.
https://www.youtube.com/watch?v=4eC6L3_k_48
I thought this one was funny.
https://www.youtube.com/watch?v=4eC6L3_k_48
Are you asking or telling.
Never underestimate what and how others are doing their job.
Hans
How can you be sure? As was discussed, possibly on this thread, anything cut after the mid 70s possibly went through a digital delay line and after 1982 probably all bar a few boutique pressings. Other than early stuff which has other issues its tricky unless you just listen to audiophool specials (of which I have many)
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