In my personal opinion, people might always know if they are hearing noise. How could that happen? IIRC, Vref (or AVCC) in a dac is convolved with the audio to produce the dac audio output. It there is noise on Vref, then it becomes part of the audio. The noise then goes up and down with the audio signal. In my personal view, there can be an audible effect, but I don't hear it as being like the way a stable noise floor sounds. Its may be more of a blur to the sound, at least to my personal perception. If my understanding is correct, similar kind of thing should be able to happen with clock phase noise, since it is also convolved with the audio inside the dac. Also, IIRC, ESS talked about noise that goes up and down with the audio in their modulator seminar from several years ago.
-
WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!
Audibility of DAC Phase Noise.
- Thread starter Wanman
- Start date
So any listening data to back up the handwave?
Robin L
Master Contributor
The OP by John Curl goes to a 404.
IIRC, Pat (Jocko) died a few year back, so no surprise.
DBT doesn't have to be ABX format. But without controlled listening data in some format, your claims are untethered from reality.
Robin L
Master Contributor
Which one? He trotted out the Bybee stuff routinely on diyA any time he felt that people weren't paying enough attention to him. Most of his stuff consisted of a lab report with some scrawls on it that he didn't understand, repetitions of wild claims about Bybee teaching superconductivity to Feynman and installing his technology on nuclear submarines, claims of deep knowledge of solid state physics backed up by scans of pages from a freshman textbook, claims that the Bybees were a classified technology but somehow released for audiophiles, and insults to anyone who questioned the stupidity of the scam. Oh, and he also claimed that the John Curl power filter sold by Bybee had nothing to do with him.
John was more pitiful than contemptible.
- Thread Starter
- #8
Understood some proper evidence would be better than none. However, ESS didn't provide evidence, nor did Purifi when Lars Risbo made claims in a post at diyaudio without providing any test result evidence: https://www.diyaudio.com/community/...-can-it-make-a-difference.384031/post-6972024
Just saying the lack of shared listening test evidence isn't unique to me. I have done enough experiments and performed tests with listeners, but its all casual work for my own use. Thus maybe I can be allowed to share an opinion without claiming the content as proven.
Just saying the lack of shared listening test evidence isn't unique to me. I have done enough experiments and performed tests with listeners, but its all casual work for my own use. Thus maybe I can be allowed to share an opinion without claiming the content as proven.
Here is the Wayback Machine version. My suggestion is not to waste too much of your time with it. Time is a non-renewable resource.
Audibility claims without evidence are entirely worthless. Even when made by a company with excellent products.
Robin L
Master Contributor
If it's the one in his living room driving the Wilsons, I've also heard it. Meh. Not terrible but not great.
Robin L
Master Contributor
There's such a thing as power supply rejection, typically measured in terms of the rejection ratio of signal to noise (PSRR), that isolates the supply and reference voltage from the DAC's output. DAC designers (and designs) take great pain to isolate the signal from power supply and other noise sources. It is true that noise on Vref could cause noise on the output, but in practice the reference is extremely well isolated from the power supply, and there is additional on-chip decoupling that reduces the coupling even further.
A similar argument applies to clock noise, since clocks are usually regenerated and filtered on-chip to isolate them from input clock noise.
PSRRR and clock noise rejection are pretty routine and allow things like multi-Gb/s Ethernet, PCIe, and SAS/SATA receivers to capture billions and billions of bits from what looks like noise without error. The same principles work for audio power supply and clock recovery systems operating at much lower signal rates. Audio does not require any special magic despite the marketing.
Noise pumping in modulators is usually from a different cause (inter-stage and internal filter issues), not related to the power supply, though I am not familiar with the ESS seminar so do not know what was going on.
I am curious the technical reasons for your personal view? What you say is true enough, but those are long-solved issues for any competent device. It does not jive with my engineering viewpoint.
I suspect @SIY was not thinking of (just) the turntable...
I remember when the Levinson HQD system was marketed as the pinnacle of speakers, but the few experiences I had hearing them, left me feeling very "meh" as well.
Robin L
Master Contributor
Curl's system didn't have low-end extension, not having the "Puppies". But what I heard had the best retrieval of low-level detail of any LP based audio system I've heard. Haven't heard that many high-end turntable-based systems in people's homes and I know there are always limitations to audio systems in audio stores and shows. I remember the WATTS at Skywalker Sound sounding terrible with a 16 bit digital source.
That is not how it works. Noise is audible as noise, With whatever characteristic the noise waveform has. Whether it is the hiss from magnetic tape (or low bit depth quantisation), mains hum, ground loop noise from a high power PC, a plane going overhead, traffic noise, - or even the noise of a dog barking, whatever - we perceive it as the noise it is. Not as a blur to the sound.
Plus every DAC recommended here - and most that are not - noise output is way way below the level of audibility.
Yes, there's no way to listen to the turntable alone. The system itself wasn't great, and in no small part due to the Wilson speakers. The lobing from the crossover was clearly audible as was the peaky treble ("low level detail retrieval").
Last edited:
- Joined
- Feb 23, 2016
- Messages
- 22,697
- Likes
- 41,883
I've heard the WATTS several times. That detail was not the detail I want in a speaker system. The lack of low end just made it worse. I can say my JBL LSR 305's are a much better monitor than the WATTS. So I concur. Mr. Wilson made them for monitor use maybe that etched detail was helpful to him in some way for that actual use in recording, but I prefer transparent monitors for that vs something intentionally skewed.
Similar threads
