In addition --- You also want to be able to remove HF but too close raises GD in audio freqs. I tried a passive 5-pole Bessel filter because of its better GD characteristic.
-RNM
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@billshurv,
Tournesol already mentioned it, does anybody know what was done as modification (under the "gunk"), we discussed the properties of
various "gunk" available for EMC and as far as I know, nobody did any measurements.
I understand that one suspects that there is nothing there, but it is just an assumption, isn't it?
@vacuphile,
I'm really interested in your reponse to my post:
John Curl's Blowtorch preamplifier part IV
As you are not following this rule it is quite strange that you demand it from others.
I demanded evidence for some of your bogus claims, you wriggled for an answer over weeks and at the end your "evidence" was pure gossip/imaginations from another forum, quite the opposite of "real facts" .
Tournesol already mentioned it, does anybody know what was done as modification (under the "gunk"), we discussed the properties of
various "gunk" available for EMC and as far as I know, nobody did any measurements.
I understand that one suspects that there is nothing there, but it is just an assumption, isn't it?
@vacuphile,
I'm really interested in your reponse to my post:
John Curl's Blowtorch preamplifier part IV
As you are not following this rule it is quite strange that you demand it from others.
I demanded evidence for some of your bogus claims, you wriggled for an answer over weeks and at the end your "evidence" was pure gossip/imaginations from another forum, quite the opposite of "real facts" .
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Hi Jacob, proof is defined differently in different disciplines. Mathematical proof does not rely on statistics, measuring auditory response in humans relies on it. So we are speaking about having some level of statistical significance in the case of auditory measurements. The level of confidence required to accept a certain outcome as proof is open to discussion and should always be made explicit.
For me, when Pavel scores a consistent 9 out of 10 on a certain auditory stimulus, I am happy to accept that as sufficient proof that something is going on.
When it comes to opamp sound, you may accept a lower level of confidence, or a higher one, all basically a matter of taste. What do you think is good enough to be convinced? Everybody may decide for themselves. After all, in the field on audio development, the outcome of such tests may deliver actionable information. Do people prefer this tweeter over that one, is it worth the extra expense, etc. For a very small difference, you might wish to lower the bar because there is always noise.
Because my narcissistic brain likes to tell me that any change involving an expenditure in time and/or money delivers an improvement, I have to be strict and test the heck out of it before congratulating myself with my own ingenuity.
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The slope for Bessel wont be as steep as others but what is the down side of that in order to have a flat GD <22Khz?
Is the GD more audible than the artifacts if not steep enough LP filter?
If we just would have changed the CD BW higher.
-RM
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The steep analogue filter after a 44.1 DAC does introduce quite some GD.
That’s why we prefer, different from what you say, upsampling to 96 or 192Khz with digital 20Khz brick wall filtering to get much less GD from the softer post analogue filter.
This brick wall filter, if linear phase as is mostly the case, has a constant GD over the FR, making the shift in GD at the higher Audio frequencies just and only caused by the analogue filter much smaller as with the 44.1 DAC.
Even at 8Khz, a GD of ca. 2 msec seems to be the threshold of our hearing system (Blauert&Laws).
Hans
No, it’s the norm.
Current theories consider upper freq. hearing loss as the underlying cause of tinnitus.
George
Can we please stop talking about GD and talk about phase shift instead? Group delay is a good metric for transmissions over glass fiber or cable because it will tell you how much a signal containing different frequencies may get smeared. This is not relevant for audio.
20 ms group delay at 20 Hz is something very different from 20 ms group delay at 20 kHz in terms of phase shift. So that is why I think using this metric for audio obscures, rather than promotes insight.
20 ms group delay at 20 Hz is something very different from 20 ms group delay at 20 kHz in terms of phase shift. So that is why I think using this metric for audio obscures, rather than promotes insight.
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Richard, you seem to lead a beautiful life. My congratulations for getting it right.
My personal experience of vinyl potions:
Stylast I use every side, every play. Easy to hear the improvement. (And my ears are beat down bad.) Have my own Wild-Heerbrug stylus microscope and see no buildup issues from it. Discwasher fluid has very bad buildup.
Last record preservative actually seems to work fine. Don't use it lately though. Applications from 45 years ago are still fine.
Soundguard destroys records.
Wet play has always been known to damage records for later dry play. It's "once and done."
Everyone needs a Keith Monks record cleaner. It's not optional.
The stylus contacts the PVC with pressures of tons per square inch and must be accelerated to several thousand Gs. Why is anyone surprised that the vinyl is deformed? Or that high temperatures occur (very) locally? Daily life experience isn't a good basis of judgement in this case.
All good fortune,
Chris
My personal experience of vinyl potions:
Stylast I use every side, every play. Easy to hear the improvement. (And my ears are beat down bad.) Have my own Wild-Heerbrug stylus microscope and see no buildup issues from it. Discwasher fluid has very bad buildup.
Last record preservative actually seems to work fine. Don't use it lately though. Applications from 45 years ago are still fine.
Soundguard destroys records.
Wet play has always been known to damage records for later dry play. It's "once and done."
Everyone needs a Keith Monks record cleaner. It's not optional.
The stylus contacts the PVC with pressures of tons per square inch and must be accelerated to several thousand Gs. Why is anyone surprised that the vinyl is deformed? Or that high temperatures occur (very) locally? Daily life experience isn't a good basis of judgement in this case.
All good fortune,
Chris
That is reported, but if that was the case a wet clean of a record would damage it... And this was tested in the last couple of years and there was no damage to the record (wet play).
If anyone HAS a record damaged by wet play please let me have it for further investigation.
Good explanation... However, the HF right after 22kHz is not attenuated enough to prevent IM further down the chain of pre/PA/Spkr.
How to fix that with existing products/devices?? Any DIY way? And, not introduce another audible condition?
THx-RNMarsh
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Are you sure, how low does the HD have to be for the IMD to no longer be an issue?
Cleaning a record and playing it are vastly different. Huge pressures are inherent in dragging a rock down the groove, and wet play is somehow different enough from intended use as to cause damage. There's a (German?) paper from modern times IIRC that discusses the damage in terms of chemical changes. I'll post a link if I can find it.
It's easy enough to sacrifice a record to see for oneself if damage occurs. Just be sure to make a safety transfer to digital while playing wet.
All good fortune,
Chris
It seems that way but anyone can do it as i do it. One must know the pit-falls and economic traps set up for us in order to avoid them and lead a more interesting life. Then, be a risk taker.. calculated risk taker. Well, sometimes not so well calculated. Maybe confidence you can find a way to pull it off. 🙂 The rest is a piece of cake. 🙂
Your experience is what most people have with LAST. Lowered distortion and longer wear of stylus and plastic. Lowered friction?
I dont know what the resistance to try new things is about here for so many. Maybe same reason they dont go on adventures to remote unknown places. I dont look for safe guaranteed predetermined results. Sort of same approach to audio also. Just try it, first.
THx-RNMarsh
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would be good.
And it ws tried on here and no damage was seen. The chemical change thing I have been assured doesn't happen by someone who works with PVC.
I probably don't understand your question.
When playing a 44.1/16 file on a DAC that does not upsample, there is indeed some unfiltered HF left of the mirrored image around 22.050.
But when playing the same file on a 192Khz upsampler such as your DAC3, the audio content is now mirrored around 96Khz, so in that case there is no HF between 20Khz and 172Khz.
However when playing a 192/24 file, you have all the higher harmonics up to 96Khz, and that's exactly what you preferred, true ?
Hans
I suspect if you play two sine waves at say 10 kHz and phase shift the one wrt to the other you are likely to hear something - but this is pure conjecture from my part. But, how does a phase shift like this happen post recording in just one channel wrt the other? It doesn't. Ditto GD.
Again, we argue about things that don't take place in a normal stereo set-up with normal good quality recordings.
Now, between two different sets of speakers - yes you will hear a difference but even though I have two pairs for everyday listening, I don't sit switching between the two to try to see if there are phase shifts between them of different GD. I just use them for the music I like on them and I'm done.
Perhaps a more interesting discussion is that Nelson Pass notes we can hear the absolute phase of low order harmonics . . .
Again, we argue about things that don't take place in a normal stereo set-up with normal good quality recordings.
Now, between two different sets of speakers - yes you will hear a difference but even though I have two pairs for everyday listening, I don't sit switching between the two to try to see if there are phase shifts between them of different GD. I just use them for the music I like on them and I'm done.
Perhaps a more interesting discussion is that Nelson Pass notes we can hear the absolute phase of low order harmonics . . .
This time we are in full disagreement.
A GD or time delay of 2msec at 8Kz means a pretty meaningless phase shift of 5760 degrees.
The same GD of 2msec means 1440 degrees at 2Khz.
So when the meaning of time delay in this case must be clear to everybody, what's the added value of knowing the phase shift.
Hans
Pavel presented foobar ABX evidence, 9 out of 10 right after after some practice. He also said that ABX is much harder than he thought compared to simply listening to a real difference.
How do you feel about ABX being much more difficult than just listening to an real difference, just like the audiophiles have said all along?
I know you can't believe you could be wrong. It happens to people sometimes.
It happened to a lot of medical doctors when Lime was finally shown to be a bacterial infection. Before that there were countless doctors who angrily threw Lime patients out of their office after calling them fakers and malingerers. Don't think the same degree of mistaken belief can't happen in audio, in fact it has. You happen to be a pretty good example of the misguided doctor syndrome as it applies to this field. Best not to be so overconfident if you want to be a good professional scientist.
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