[knownothing2]

Firstly, what you have suggested would require considerably more than a 1 in a hundred bit error rate (BER) and Secondly, if the actual BER were even 1 in a million, then USB would be unusable. The vast majority of all files transferred over USB would be at least somewhat corrupted, so the obvious question is; are they? How many times have you experienced it? Are aircraft constantly crashing into obstacles?

Thanks again for reading my posts and providing complete replies. I suspect this is not a disk error, but rather an increase in jitter (and/or some other form of noise) as a result of the combined performance of the cable, the power supply in the Node, and the processing within the Node that results in a different quality signal being fed to my external DAC. It is not a fatal problem, music comes out, it is a quality problem. And I am not claiming this is a universal problem, but it is my problem with my particular gear and setup.

kn

 

[sander99]

For the record, I expected the HDD drives to sound the same or better with the Bluesound Node than the flash drive.

I hadn’t given it any thought at all

I literally had no expectations at all, but was disappointed when the quality of sound was clearly degraded.

Anyway, that contradiction doesn't even matter. There is conscious and subconscious bias, and many more forms of bias than only expectation bias. There are countless possible ways how some sort of bias could make you perceive what you perceived.

 

[bigshot]

Jitter is at least an order of magnitude below the threshold of audibility in the worst cases. This is expectation bias. Bfreedma is right. Until you rule that out, it’s the most likely explanation. You’ve demonstrated that your expectation about what causes the differences you hear are deeply embedded and you resist even clear and logical evidence based explanations in favor of your uninformed guesses. You’re one of the best examples of bias that I’ve ever seen. You’ve spent hours and hours defending your bias. It may not be possible for you to get past it.

 

[sander99]

Thanks again for reading my posts and providing complete replies. I suspect this is not a disk error, but rather an increase in jitter (and/or some other form of noise) as a result of the combined performance of the cable, the power supply in the Node, and the processing within the Node that results in a different quality signal being fed to my external DAC. It is not a fatal problem, music comes out, it is a quality problem. And I am not claiming this is a universal problem, but it is my problem with my particular gear and setup.

kn

Ah, good to know you use an external DAC. I still could see a slight, slight possibility that a hdd drawing more power from the node could influence it's analog output performance (in which case the node was not designed to power an external hdd, so it would be a case of user error or wrong specs/instructions by the manufacturer). But now that you use an external DAC... my bet is on bias.

 

[knownothing2]

Anyway, that contradiction doesn't even matter. There is conscious and subconscious bias, and many more forms of bias than only expectation bias. There are countless possible ways how some sort of bias could make you perceive what you perceived.

Yes, I did note that if anything my expectation was that the higher storage HDD would sound at least as good if not better than the flash drive. But it was not a firm expectation. Not like when I buy a different pair of speakers or headphones and have expectations that they will sound different. What I clearly did not expect is that the HDD would sound worse than the flash drive. I was not prepared to listen to or for a difference, it just hit me over the head, or more accurately in the foot, because when listening to Casandra Wilson’s version of Bob Dylan’s “Lay Lady Lay” my foot stopped tapping when the 24/96 files were served from HDD.

kn

 

[bigshot]

Yes, I did note that if anything my expectation was that the higher storage HDD would sound at least as good if not better than the flash drive.

Unconscious bias is unconscious. You can’t direct it or turn it off. You can only filter it and reduce its effect through controls on your comparison and isolating variables. If you don’t do those things, anything you hear is suspect.

 

[knownothing2]

Jitter is at least an order of magnitude below the threshold of audibility in the worst cases. This is expectation bias. Bfreedma is right. Until you rule that out, it’s the most likely explanation. You’ve demonstrated that your expectation about what causes the differences you hear are deeply embedded and you resist even clear and logical evidence based explanations in favor of your uninformed guesses. You’re one of the best examples of bias that I’ve ever seen. You’ve spent hours and hours defending your bias. It may not be possible for you to get past it.

And thank you for spending hours and hours attempting to explain to me the difference between electrical engineering and the science and art of recording in digital reproduction of music, and the psychological processes behind the observer-expectancy effect. Come here for the science behind sound stage reproduction in DACs and get a lesson in psychology, win-win. I am not sure who charges more per hour, consulting engineers or clinical psychologists, but either way, all this great information should probably be behind a paywall.

kn

 

[knownothing2]

@knownothing2
Well, you should know the drill by now. Jitter and digital noise that is audible like that can be captured in vivo because human perception is measured in ms, which is plenty to be captured by a mic. If you are getting audible errors that bypass Reed Solomon without complete failure, let's see the recording. If there is a significant deviation in the null test, maybe we can replicate your results.

As I brought this up on this forum, I considered how I could duplicate the result. I have made several changes that would make it difficult to replicate with my current gear. I returned the HDD that sounded the worst to me to the vender. I still have the better sounding of the two HDD drives and I am using it in my office computer-based music server, so not with the Node - but it is available to retest as you suggest.

My main system has been altered significantly since I experienced this “problem”. I now have a different (but similar) DAC, and I replaced the internal power supply for the Node with a higher quality external supply providing 5V and 3A to the streamer. I could probably get ahold of a stock Node with the switching supply, a microphone, and several different HDD and SSD drives and test the audio performance of different drive formats with both the internal DAC in the Node and my external DAC. I could also look at whether the Node with the external power supply has the same apparent performance issue with the different drive formats.

kn

 

[Davesrose]

Given the facts, it seems there's an unconscious bias going on. This video goes over the difference between USB, ethernet, and toslink connections, and how none of them are prone to jitter distortion in real life. USB and ethernet are free from jitter because the audio is asynchronous. In theory, toslink could have jitter because the target device could be waiting for the next packets of data. But the argument is that even that kind of connection is irrelevant: the only audible distortion being that of the cheapest DACs.

 

[knownothing2]

This link would tend to support both my suspicions of the differential performance being power supply related and also suggestions here of operator error on my part. It is curious to me that the issue manifested in a slight but noticeable difference in the sound quality of the music reproduced when using the different drives, but not in complete or partial failure to retrieve and serve files to the DAC.

https://support1.bluesound.com/hc/e...-A-Local-Library-when-Server-Mode-is-disabled

kn

 

[Davesrose]

This link would tend to support both my suspicions of the differential performance being power supply related and also suggestions here of operator error on my part. It is curious to me that the issue manifested in a slight but noticeable difference in the sound quality of the music reproduced when using the different drives, but not in complete or partial failure to retrieve and serve files to the DAC.

https://support1.bluesound.com/hc/e...-A-Local-Library-when-Server-Mode-is-disabled

kn

Not sure how that link can confirm your ideas-it does not go over audio distortion, or that power supplies affect digital audio quality (I'm sure the DAC manufacturer wouldn't want to say they have a poorly designed product). It says depending on USB mode, it can load 1000 songs per minute in index, or 500 songs not indexed. That's certainly a higher data rate than the bandwidth of one song. Edit, last item in table mentions using an external supply for a USB 2 device that requires more power to operate. That case also doesn't indicate difference in audio quality. If you don't have external power with that device, then the computer/DAC doesn't recognize it.

 

[bigshot]

How hard can you try to avoid the obvious conclusion that your listening comparison technique is the problem, not the equipment? You’re becoming a hopeless case.

 

[knownothing2]

Edit, last item in table mentions using an external supply for a USB 2 device that requires more power to operate. That case also doesn't indicate difference in audio quality. If you don't have external power with that device, then the computer/DAC doesn't recognize it.

I don’t have an external power supply for the 2T HDD drives, and they do have full functionality for storing and retrieving music files to the Node. It’s just that the sound quality is affected. Here is a more detailed discussion of this issue with the Node - noting that I am operating the Node past it’s recommended use by attaching any USB storage device larger than 2T. I may be further pushing the envelope by attempting to use an HDD that undoubtedly has a greater current draw than a flash drive. In any case, I did not experience any of the more major issues described in the link below. Just different sound quality via the Node and external DAC.

Now that I have added a more robust external power supply for the Node, I wonder if this would still even be an issue.

https://support1.bluesound.com/hc/e...ered-USB-Storage-Devices-to-Bluesound-Players

kn

 

[bigshot]

It doesn’t appear to have nothing to do with the hard drives.

 

[Davesrose]

I don’t have an external power supply for the 2T HDD drives, and they do have full functionality for storing and retrieving music files to the Node. It’s just that the sound quality is affected. Here is a more detailed discussion of this issue with the Node - noting that I am operating the Node past it’s recommended use by attaching any USB storage device larger than 2T. I may be further pushing the envelope by attempting to use an HDD that undoubtedly has a greater current draw than a flash drive. In any case, I did not experience any of the more major issues described in the link below. Just different sound quality via the Node and external DAC.

Now that I have added a more robust external power supply for the Node, I wonder if this would still even be an issue.

https://support1.bluesound.com/hc/e...ered-USB-Storage-Devices-to-Bluesound-Players

kn

Sorry, that link also doesn't indicate an audio quality issue. It's just expanding on the issue of drive not being recognized if it doesn't have its external power supply (which would be older USB 2 drives: portable USB 3 drives all can be powered directly off USB). It confirms that if you're running a USB drive that doesn't have adequate power, it would either not be recognized (typical) or may have issues indexing. Drive size also doesn't have any effect with a file's "audio quality". If a link about a media player is talking about drive size, it's typically talking about size limitations depending on file system format. FAT32 being the most universal for a device's OS to be able to read and write...but has partition size and file size limits. FAT32 is limited 2TB disk size (or partition size) and with actual file limitation: it gets into the inability to store large movie files, not a stereo song. ExFAT is considered more universal for various computer OSes (and doesn't have these file limitations). But some Linux based devices won't write to that format.