I agree with you and think that any possible improvement should be investigated. More so when it is so easy and cheap.
That does mean you should limit this to only a few convenient truths. First start with the assumption that it does not work and then that it does not work in the way it has been explained.
That does mean you should limit this to only a few convenient truths. First start with the assumption that it does not work and then that it does not work in the way it has been explained.
I agree too, that any improvement it should be investigated. This I stated from the beginning of this thread. The improvement by using this cap is so, and it could be fortunate to find an answer about why is like this.
The only disturbing in this process is the trial of some ones to mislead the subject to something else than it actually is...
The only answer that cap act as a filter it is not enough in my opinion, to have an comprehensive explanation about this occurred improvement. A filter it filter something from something else. What is filtered here to get an improved precision for sound sources locations in a soundscene? No answer yet...
I`m not very sure about what you mean in the last phrase of your post.
This cap used so as described improve the overall performances of a sound/audio system. This is very true in my opinion. For practical reasons (I can not invite all the sceptics to my place to show and demonstrate that there is an improvement in using this circuit, as the sceptics can not accept a such eventual invitation...) these improvements it can be demonstrated by only DIY on your own device, and observe the results.
The further discussions it can occur here (if not disturbed/distorted).
So, what you ask for be explained?
The only disturbing in this process is the trial of some ones to mislead the subject to something else than it actually is...
The only answer that cap act as a filter it is not enough in my opinion, to have an comprehensive explanation about this occurred improvement. A filter it filter something from something else. What is filtered here to get an improved precision for sound sources locations in a soundscene? No answer yet...
I`m not very sure about what you mean in the last phrase of your post.
This cap used so as described improve the overall performances of a sound/audio system. This is very true in my opinion. For practical reasons (I can not invite all the sceptics to my place to show and demonstrate that there is an improvement in using this circuit, as the sceptics can not accept a such eventual invitation...) these improvements it can be demonstrated by only DIY on your own device, and observe the results.
The further discussions it can occur here (if not disturbed/distorted).
So, what you ask for be explained?
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IIRC, he advocates values as high as 1uF directly across Delta-Sigma modulated DAC balanced outputs.
These outputs lines prior to RC or active filtering are PWM rectangular pulse trains, effectively switching between the DAC B+ and B- supplies.
The above mentioned 1uF cap is effectively directly across the supplies, at least some of the time.
The output spectrum extends to very high frequencies.
Any LP filtering at the DAC outputs prior to post active and/or RC stages can only be of benefit.
Mr Rasmussen also advocates connecting a high internal resistance (40R) supercap across the DAC supplies.
This is effectively an infinite capacitance Zobel across the supplies.
Dan.
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You still haven't taken the first steps. Step 1: determine that this is audible to you. Step 2: if it is audible, determine if it sounds any different than the same EQ placed elsewhere.
Skipping those steps means that everything that follows is indistinguishable from commonly repeated claims of alien abductions and anal probing. One doesn't speculate on which of Jupiter's moons is the source of the Alien Grays until you first determine that there actually ARE Alien Grays.
Sy, why do you have an obsessive interest in anal probing?
Don't we spend billions looking for aliens anywhere?
Don't we spend billions looking for aliens anywhere?
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I have never been abducted by aliens. Many people worldwide claim to have been and there's lively discussions about it, speculating on the various types of aliens and their origins. The evidence to support those claims is of the same quality as the evidence presented so far about this alleged "effect."
Here's a review. Note some disturbingly similar forms to the claims and evidence:
Alien abduction - Wikipedia, the free encyclopedia
See the section on "Examination." Also, for a bit more exhaustive look at the anal probing part:
Aliens and Anal Probes - Jason Colavito
A wonderful pop-culture nod to the alien anal probes:
https://vimeo.com/98216067
Would you care for some links to the once widely believed "fairies in the garden" tales? Or do you agree that your time would be better spent actually trying to determine if your alleged "effect" is a real one and if so, if it's specific to that circuit position (as claimed)?
https://www.youtube.com/watch?v=HPl10L40pBM
Here's a review. Note some disturbingly similar forms to the claims and evidence:
Alien abduction - Wikipedia, the free encyclopedia
See the section on "Examination." Also, for a bit more exhaustive look at the anal probing part:
Aliens and Anal Probes - Jason Colavito
A wonderful pop-culture nod to the alien anal probes:
https://vimeo.com/98216067
Would you care for some links to the once widely believed "fairies in the garden" tales? Or do you agree that your time would be better spent actually trying to determine if your alleged "effect" is a real one and if so, if it's specific to that circuit position (as claimed)?
Billions? I don't know, but I suspect the number is considerably smaller. The Drake equation is depressing in this regard.
https://www.youtube.com/watch?v=HPl10L40pBM
There is a wonderful word to describe this: chutzpah! However, it might explain why attempts to explain the alleged effect using mere circuit theory were brushed aside.Mark Whitney said:
Maybe we should all set up websites to collect money for our bright ideas. Let's not waste time trying to test whether the idea really works, or how it works, or whether it could possibly work, or whether it is a relatively trivial result of how circuits work anyway.
I once wrote some articles for WW on how the complementary feedback pair works. From now on, anyone using the information in those articles to design or correctly bias a feedback pair should pay me some money.
That suggests another possible mechanism to explain the effect:Max Headroom said:
the added cap greatly boosts the output stage switch current, thus adding lots more switching noise to the supply rails. It is well known that added noise can be misinterpeted as extra 'detail' or 'sparkle' - that is why appallingly poorly constructed DIY interconnects are so popular in some quarters (or their expensive commercial equivalents).
Not necessarily, a cap can move the switching noise to somewhere else. Put a cap at the output of a switch and you increase edge current. This comes from the supply rails, so you need much better rail decoupling to avoid making the situation worse rather than better.
As I often say, it is easy to make a circuit sound different. To make it sound better, you first need to understand it better than the original designer. Few tweakers do.
As I often say, it is easy to make a circuit sound different. To make it sound better, you first need to understand it better than the original designer. Few tweakers do.
It can, but it can also increase it. It's a pretty simple matter to measure the analog output of the DAC or CD player.
Depends, as others mentioned.
Look at it this way, take an RC fiter to attenuate noise. Does the cap 'remove' the noise? Not really.
The cap has a very low impedance for hf noise so the attenuator formed by the series resistor and cap to ground is just that, an attenuator. And as with any attenuator, the signal (in this case the noise) is attenuated such that most of the noise appears on the large impedance (the series resistor), and very little left on the lowest impedance (the cap to ground).
So the noise is still there, but now it is almost all across the resistor....
Is that Good? Depends. 😉
Jan
This thread really is special, IMO.
While there's no shortage of threads chock-full of arguments between "objectivists" and "subjectivists", this is the only one I'm aware of where both camps actually agree on something, then argue about it anyway.
Seriously, when you've got engineers like Scott Wurcer recommending a cap across the dac output for technical reasons, and you've got listeners like Coris recommending a cap across the dac output because it results in audible improvements, you'd think that would be the end of it, but no....
weird!
While there's no shortage of threads chock-full of arguments between "objectivists" and "subjectivists", this is the only one I'm aware of where both camps actually agree on something, then argue about it anyway.
Seriously, when you've got engineers like Scott Wurcer recommending a cap across the dac output for technical reasons, and you've got listeners like Coris recommending a cap across the dac output because it results in audible improvements, you'd think that would be the end of it, but no....
weird!
The issue is that the 'audible' people claim that the 'improvement' is not due to the 'technical reasons'.godfrey said:
I should mention this detail too from the very beginning, but unfortunately, I omit it. I use very large capacities (0,5/1F) as decoupling for AVCC-VddL/R, and I used also the same approach on PCM1792, while experimenting with this cap/effect.
I think you right about extended output capabilities for very high frequencies spectrum. I have measured the device outputted signal, and I could notice an increasing of Vpp levels for 40Khz and 80Khz, as the cap`s value increased.
But all these things are about applying this cap at the DAC outputs. I could observe the same effect, when placing this cap in another place over the differential lines (at the preamp inputs). In such case it will differ a little bit the effect explanation...
I have expected that a such high capacities of 1µ introduced into the signal path it should have a strong impact over the audio signal. Nothing like this. Just excelent fidelity, and even more imprving a lot the soundscene quality.
Well, god point. Not tried it actually...
I really do not own a good enough headphones pair, and I dismissed the headphone out in my device, as not interested in such configuration. But for the experiment here it could be interesting to used it...
Sorry, I have no answer to your question.
Not really even a good question- the number he throws out is complete nonsense, off by more than three orders of magnitude.
Very wrong!
There are of course technical reasons for that this cap placed so, it works and it improve the outputted sound/fidelity...
To find these technical reasons it should be the target of this discussion/thread.
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