Here's a suggestion: if you really believe you have a hornless unicorn and not a common horse, you should really try to patent the innovation and then license it to the industry. That way you can laugh all the way to the bank while us closed-minded engineer-type guys will have to continue to sit in our cubicles endlessly designing inferior DACs.
Re-read your own words:
How am I mis-characterizing? You tell me not to comment. That's easily seen in your comment presented above.
Wow! That is the pot calling the kettle black. You refuse to see that's there's nothing but a simple filter here and call me close minded because I refuse to see the grandeur of said discovery.
All I've done is to report what I hear, and to suggest that others should first see whether or not they hear the effect before dismissing it as fantasy. Apparently, that's suggesting too much? Your response has basically been that not only have you not tried it for yourself, you do not plan to try it. All I can say is that I hear it, while some don't seem to want to even find out whether they can hear it or not. I don't know what else to say to them.
The signal is measured at the final opamp output. For I/V is used OPA1632. Now any filtering in between I/V and final.
A quick observation is that this kind of filtering it increase the HF noises on the system outputs. This increasing of HF noises it happen in a slow rate as the capacity increase, until it is reached a so called critical point, when suddenly the HF noises increase very abrupt on RCA output (as to be seen in the last picture). Until one reach that critical point, even though the HF noises increase in the system, the perceptual quality of the sound increase too, as the cap value increase (I started with 100pF and ended with 1n). Over that critical point, one get a quite bad signal, and is to be observed strong degraded audio signal. This degradation of the audio signal does not mean distorted sound or so, but the sound scene disappear or become flat, and a bass dominant sound is obvious. Else it still be a clear and clean audible audio signal.
I do not consider these (mine) measurements as enough accurate at the moment. Just as an illustration of what it happen in a "raw" mode. I intend come back with more detailed measurements, when a better implementation/circuit will be finish.
I still listen the system which it were measured (pictures), with a cap value into the critical zone, and I can only say that the sound is as never heard before... Just impressive, as Ken already described very well.
I can well understand that some one will be sceptic that these things works. I was too, until I have tried it. Now I`m just curious to find out more about why and how.
I`m quite sure that the sceptics who reject now this filtering technique (as nothing or wrong way) will experience the same as I did... after it will be trying it by them selves.
And all we have done is explain why it is that it sounds the way it sounds. Nobody is saying you don't hear "it". All we are saying is "yes, that is the way it should sound, when the DAC has the low pass filtering it is supposed to have".
We are not doubting that you are hearing a horse-like creature. What we are saying is that it is a horse, not a horn-less unicorn.
That comment began with the following words; "Here's what I will suggest...."
You, apparently, have a reading comprehension problem. Not to mention, the evident need to be argumentative. There's nothing to be gained in our continuing this sort of back-and-forth. So, I will stop.
It is just a normal filtering technique, apart from the fact that it might cause oscillation/ringing in the DAC due to capacitive loading.
My question is, how can you suggest anything about what others are hearing without first finding out what you hear? You're making an intellectual assumption about what the the sound must be. By the way, until I conducted an experiment and heard the effect for myself, that was the same assumption I had. 🙂
Ken, I agree and I just think that is not worth for anybody to get into a quite personal conflict in changing opinions about this subject. This it may be a trap we may avoid.
The ones who reject this way of doing are free to do that. We may keep to try only to find out more if possible and discuss the subject with them who really want to discuss it.
I have experienced myself this before, Joe the same, as maybe many other who never come back in the forum because such behaviours from they who already knows best or everything.
The ones who reject this way of doing are free to do that. We may keep to try only to find out more if possible and discuss the subject with them who really want to discuss it.
I have experienced myself this before, Joe the same, as maybe many other who never come back in the forum because such behaviours from they who already knows best or everything.
You should be a comedian. You've spent the day arguing that this is more magical than a simple low-pass filter, yet you accuse me of being argumentative. And then you feel the need to throw an insult about reading comprehension in there for good measure. Oh, the irony!
OK, is just a normal filtering technique, but then why the sound out of this technique is different than the sound of the classical technique? This is the question...
I have done the classical technique. I was bad in my opinion. Bad highs and bad or non existing sound scene. This simple cap over the phases bring all in its place... There have to be a difference...
No one has rejected this way of doing it. We're rejecting that there's something magical or more than a simple filter. There's no harm in doing this way, as long as the DAC (and I/V) behaves, it just that claiming that it's a breakthrough is baseless. It's simply another way of accomplishing something.
OK, there is no magical, or there is... No matters. Please try this, and we can "talk" after...
As a science man you may agree with this procedure...🙂
As a science man you may agree with this procedure...🙂
I'm not trying it for the same reason I'm not making tea with dog feces just because someone told me I have to before I can say the result is no different from what I would expect. This is an elementary thing, it's not magic.
If you like the results and feel that there is a difference (the placebo effect is real, not to mention the rare chance the circuit is now misbehaving and the result is pleasing to you) that's fine. Just don't tell me that I have to try it to not believe it differs from a simple low-pass.
Good question. The readily observable difference is in the filter's pass-band response. Normally, we would want the output filter to minimally impact the pass-band, ideally being completely flat at 20KHz. What Joe found is that placing a single-pole filter that is -1.5dB @ 20KHz causes the subjective character of CD playback to change significantly for the better. The effect seems to 'turn off' if the same filter is then set to provide a pass-band that's flat to about -0.5db @ 20KHz or better. One of the purposes of opening this thread is as a way to encourage others to experiment for themselves, since it is so easy and inexpensive to try. This is a DIY forum. Who knows, maybe those of us who claim to hear the effect are seeing, or rather, hearing, unicorns. 😀
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Originally Posted by Julf View Post
So clearly you agree we need some form of analog low-pass filter. How is the capacitor inserted by Joe Rasmussen any different than the cable capacitance? All he has done is ensured *sufficient* capacitance.
Referring to the quoted post, I may say that one will not expect to connect a cable where these caps are connected...😀
In my experiences I have started using a 100pF. I have observed improvements in sound stage at this value. One can not state that a such low capacity it will affect something in the audio pass band... The effect it may turn on quite far from the pass band of audio signal... But it may be more accentuated near to the audio frequency spectre. Is only my speculation now, but this have to be measured more accurate.
Yes, very true! The main meaning of starting this thread is to make known about this, so as many should try and hear with own ears. Then discuss about....🙂
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Was the -1.5dB @ 20KHz measured or calculated ? (ie, where does this number come from ?)
That's what a cap placed at the opamp inputs would do...
That's when too much cap makes the opamp go unstable...
Fascinating isn't it ? That's the most interesting thing here IMO. The signal looks like complete crap yet you say it sounds good, that's strange...
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