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Re: USB transient noise with external DAC

Reply #50

I remember that thread.  Sorry, but it is difficult for me to comprehend your testing.

The tests are in a common format that is well-understood by people who are qualified to judge this kind of data.

Perhaps this short article might help:  http://www.edn.com/electronics-blogs/bakers-best/4313869/Understanding-FFT-plots

One important point to mention is we are not rich enough to buy a dedicated hardware audio analyzer like Audio Precision. So we usually use another audio interface with significantly better technical specs than the device under test to perform a recording. For example I used a X-Fi Titanium HD to test the Realtek device. You can see the measurement limit of it in this thread:
https://hydrogenaud.io/index.php/topic,100481.0.html

Notice that some people used the same Realtek device's ADC to test its output (self loop) without knowing that the the ADC is actually worse than the DAC, and produced much poorer and useless results.

Regarding your worries about resampling artifacts and jitter, if such artifacts are measurable they will show up in the analysis graphs. For example, I identified bad resampling algorithms in this thread:
https://hydrogenaud.io/index.php/topic,111806.msg922702.html#msg922702

...and excessive jitter in this thread:
https://hydrogenaud.io/index.php/topic,104390.msg856574.html#msg856574
The attachment is here. The original link doesn't work since the forum system upgraded.
https://hydrogenaud.io/index.php/topic,104406.0.html

Most Realtek devices are only capable of 90-100dB SNR (except the flagship ones like ALC1150) but the amount of artifacts generated from a good resampler and the amount of jitter you worried about is well below it, which means such artifacts are buried inside the noise floor already. If you can really hear them you will be troubled by the noise itself rather than resampling artifacts or jitter.

When I see an unreasonable result in someone's test I will also ask the tester to explain the testing procedure and post the actual audio files so that I can further analyze them, like this one:
https://hydrogenaud.io/index.php/topic,111411.0.html

You can also visit Arnold's old website to find more audio equipment tests and explanations of technical terms.
https://web.archive.org/web/20050205165846/http://www.pcavtech.com/

Disclaimer: I only described how I interpret the measurements without claiming actual audible differences.

Re: USB transient noise with external DAC

Reply #51
This has been a very interesting experience with two technically erudite members giving their ideas.  Schitt has notified me they will not charge a restocking fee, but they could not replicate the problem.  Perhaps there is some site specific thing going on with the AC power in my hacienda. 

While this was going on I updated the Realtek driver with the latest on Intel's site.  It is enough of an improvement that it makes me think the driver I was using was broken.

I am going to try and back off from this issue for a while.  Some of the possibilities:
1.  Try an inexpensive, but well liked DAC like the FiiO E10k.
2.  Try the Audioengine D1, as it has a volume control.
3.  Look at some of the fancier DAC's with preamp functions designed in.  These start at $400
4.  Do nothing and spend the money on music and bar tabs :)

Re: USB transient noise with external DAC

Reply #52
I am going to try and back off from this issue for a while.  Some of the possibilities:
1.  Try an inexpensive, but well liked DAC like the FiiO E10k.
2.  Try the Audioengine D1, as it has a volume control.
3.  Look at some of the fancier DAC's with preamp functions designed in.  These start at $400
4.  Do nothing and spend the money on music and bar tabs :)

I like your conclusions!  :)

Just to add my personal experience: The Audioengine D1 has been absolutely trouble-free for me, with impeccable sound quality (i.e. it's a competently assembled DAC).
I bought it for the volume control, so I don't have to contort myself each time I need to reach the volume control of my speakers.

I found two small points to criticise only:
The D1's headphone output is a bit "hot" when used with sensitive IEMs, but still usable (I just have to keep the volume control very low). It's great with bigger, less sensitive headphones.
Strangely, the volume control has no engraving to use as visual reference. That's quickly fixed with a pencil, though.

Cheers!

Re: USB transient noise with external DAC

Reply #53
I can also list some candidates but I have used none of them so don't know if they are trouble-free or not.

Asus Xonar U7
https://hydrogenaud.io/index.php/topic,107822.0.html
They criticized the quality of its headphone amp but it seems that you only use speakers so if you don't mind it can be a good solution.

Creative X-Fi HD (Digital Music Premium HD)
http://us.creative.com/p/sound-blaster/sound-blaster-digital-music-premium-hd
A very rare product features phono preamp and toslink I/O and native ASIO driver. You may worry about wasting money to buy features you never use but the fact is that is it pretty cheap and the measured performance is also very good.

Xonar U7 vs X-Fi HD review:
http://www.ixbt.com/multimedia/soundcard-duel-jan-2014.shtml

SMSL M3
Can be bus or battery powered with a USB power bank, it also has coaxial and optical SPDIF input. The volume knob only affects headphone out, not line out.
Review:
https://youtu.be/7QwD5Byp1AU

Re: USB transient noise with external DAC

Reply #54
The creative item is available locally for about $80.   The reviewer (in machine translated Russian) did not like any of the products.

Re: USB transient noise with external DAC

Reply #55
The creative item is available locally for about $80.   The reviewer (in machine translated Russian) did not like any of the products.

More to the point, did you find any spec sheets or reviews that covered the power-management related transients that cause you such a concern?

Re: USB transient noise with external DAC

Reply #56
The creative item is available locally for about $80.   The reviewer (in machine translated Russian) did not like any of the products.

More to the point, did you find any spec sheets or reviews that covered the power-management related transients that cause you such a concern?

I can't find any solid information on the problem.  Tech at Schitt said my problem was connecting directly to a power amp with no input control.  The Audioengine D1 has a variable output line out (pre out).

Re: USB transient noise with external DAC

Reply #57
The creative item is available locally for about $80.  The reviewer (in machine translated Russian) did not like any of the products.

More to the point, did you find any spec sheets or reviews that covered the power-management related transients that cause you such a concern?

I can't find any solid information on the problem.

That was my experience. One reason why I couldn't in good conscience recommend that you get another DAC. I had no review or spec sheet from any product to look at that said that it promised to be free of the problem.

Instead, the silence on the topic was deafening even when the transients from the problem were deafening and dangerous.

Quote
Tech at Schitt said my problem was connecting directly to a power amp with no input control.

In an ideal world an input level control, which is really just an avenue for requiring manual intervention, should not be required to make a product properly incapable of damaging equipment downstream from it.  The product should be unconditionally transient-free and many are.

One common way to make a product unconditionally safe is to build in a relay that mutes the product's output until the product's internal voltages have stabilized and the product is safe.  My first high powered amp - a Dyna 400, did that, and my last power amp, a Denon AVR does that.

Quote
  The Audioengine D1 has a variable output line out (pre out).

That is a nice feature, but IMO it should not be the entire safety net for the whole system. Ideally, the equipment would be fail-safe, and much of it is. Its just that reviwers don't often check for this, and spec sheets don't always make that kind of a claim, even when it is true.

Re: USB transient noise with external DAC

Reply #58
I had an Audioquest Dragonfly 1.2 here for a week.  It did not have loud turn on transients.  It did have a volume control.  I sent it back because the sound was nearly instantly fatiguing.  It's possible the very low output impedance of it's headphone jack did not play well with the 33k input impedance of my amp.

http://www.audioquest.com/usb_digital_analog_converter/dragonfly-dac
Quote
Whether you’re on the go or at home, listening on ear buds or connecting your computer to a stereo system, DragonFly reveals all the emotional expression and nuance that makes your favorite music, or movies, so enjoyable.
So AQ made a false claim about the product.

When I read D1's spec:
http://audioengineusa.com/Store/D1-24-Bit-DAC#C
Quote
Input sample rate (USB)
32kHz-96kHz native playback
188.2kHz & 192kHz re-sampled to 96kHz
188.2kHz? I suppose it means either 88.2 or 176.4. I am not talking about the resampling itself but they should proofread carefully when writing important information like specs. Also the cables they sell on the right hand side of the page should be 10 times cheaper, I don't know if it is also typo or not.

But the good thing is they offer 30 days money back guarantee.

Re: USB transient noise with external DAC

Reply #59
I have decided to do the safe thing and defer any purchase.  As noted above I should not need a volume control as a safety device.  I don't with the motherboard ALC283.  It may not have impressive specs, none are published, but it does not have serious defects either.  I can move the mouse violently and there is no noise.  I am more or less convinced Realtek's method of getting 44.1 native on a device with a 48 clock isn't defective even if I don't fully understand the mechanics of what is happening.

In one of the threads another forum member said he got good results by reducing the buffer size and buffering the file in memory.  Removing the old Realtek driver provided on Intel's site helped.  It might have been broken.  There does not seem to be an identifiable difference between the updated Realtek driver and the native Win 10 (anniversary build) driver from M$.

The Sound Blaster card mentioned above has a strange implementation.  It only does 48k and 96k.  44.1 has to be resampled in software.

My experiences to date tell me line out is a must because a headphone out jack plugged into a high impedance load may or may not work.  Just in case USB noise turns out to be a problem, it's nice to have Toslink available.

Re: USB transient noise with external DAC

Reply #60
I have decided to do the safe thing and defer any purchase.  As noted above I should not need a volume control as a safety device.  I don't with the motherboard ALC283.  It may not have impressive specs, none are published, but it does not have serious defects either.  I can move the mouse violently and there is no noise.  I am more or less convinced Realtek's method of getting 44.1 native on a device with a 48 clock isn't defective even if I don't fully understand the mechanics of what is happening.
It seems to be the best solution since I didn't see you have any valid complain about the Realtek in any audible way.

It is not also very sane to have too much fear about resampling. Do you know how a bad resampler can sound? Try this foobar plugin:

http://www.foobar2000.org/components/view/foo_dsp_multiresampler

Set this resampler to output at 48khz when listen to 44.1k files in order to activate the resampler. You can choose different resampling algorithms and hear the results. If you want to do a blind test you should use foobar's file converter (right click a song in the playlist and choose Convert >> ...) with this resampler added in the DSP chain. After you exported the files you can use the ABX Comparator to quiz yourself.

http://www.foobar2000.org/components/view/foo_abx

All of the resampling algorithms offered by the Multiresampler are technically inferior to SoX, foobar's build-in resamplers and Window's build-in resampler. If you cannot hear artifacts at least in one of the algorithms then I doubt you should really worry about bad resampling. Windows 7's build in resampler had a bug in the past but a hotfix solved it and I suppose Windows 10 should not made a regression as well.

http://support.microsoft.com/kb/2653312

Re: USB transient noise with external DAC

Reply #61
My experiences to date tell me line out is a must because a headphone out jack plugged into a high impedance load may or may not work.
You previous post about this claim was removed because of TOS8. I have no opinion about this claim, just think AQ should be careful when they describe their products. However I think you should let the mods here agree with you in order to prevent further removal of your posts.


Re: USB transient noise with external DAC

Reply #62
bennetng, unfortunately TOS 8 is necessary due to the prevalence of BS in the audio industry.  It only applies to what is posted in this forum.  If I decide to buy an external DAC for whatever reason, that is up to me.  I don't have to convince you or anyone else. 

I spend a lot of time on photography.  Photographers train and trust their eyes.  This predisposes me to trust my senses and leaves me foundering within the culture here.  I will do my best to obey the rules...

Re: USB transient noise with external DAC

Reply #63
My experiences to date tell me line out is a must because a headphone out jack plugged into a high impedance load may or may not work.  Just in case USB noise turns out to be a problem, it's nice to have Toslink available.

Headphone jack into high impedance is fine.  You can always drive a smaller load with a stronger source.  Being overspeced is will work fine, just not efficiently.

If headphone jack into line out works or not depends on the voltage.  Typical consumer grade headphone jack is usually on the order of 0.2 to 1 Vrms maximum, so you may have to fiddle with the volume to get the level right.  Depending on the source and what level your line in is expecting, you may not be able to get the voltage to the optimal level, although usually this isn't a huge problem.

Re: USB transient noise with external DAC

Reply #64
TOS 8 is necessary due to the prevalence of BS in the audio industry.
That may be one reason yes, but I assure you that combating audio industry BS was not the reason why the rule was created.  The rule was created to help ensure that discussion can operate from reality.  It is a complete waste of time for others to chase after things that may only have been concocted within the head of the poster.

I spend a lot of time on photography.  Photographers train and trust their eyes.  This predisposes me to trust my senses and leaves me foundering within the culture here.
my my.

I will do my best to obey the rules...
That's all we can hope for.

Depending on the source and what level your line in is expecting, you may not be able to get the voltage to the optimal level, although usually this isn't a huge problem.
It certainly isn't a problem that is characterized as fatiguing.
Is 24-bit/192kHz good enough for your lo-fi vinyl, or do you need 32/384?

Re: USB transient noise with external DAC

Reply #65
So much for my theory on the Dragonfly... 

Re: USB transient noise with external DAC

Reply #66
Quote
connecting your computer to a stereo system
So AQ made a false claim about the product.
In case I overlooked something, aside from the absurd marketing fluff, what was the basis for accusing Audioquest of making a false claim regarding the implied ability to connect the Dragonfly to a line input?
Is 24-bit/192kHz good enough for your lo-fi vinyl, or do you need 32/384?

Re: USB transient noise with external DAC

Reply #67
Right. The end of that sentence should be replaced with a question mark.

Re: USB transient noise with external DAC

Reply #68

I spend a lot of time on photography.  Photographers train and trust their eyes.  This predisposes me to trust my senses and leaves me foundering within the culture here.  I will do my best to obey the rules...

That's logic of a kind, but the fact that reliably visible differences exist in the realm of photography proves nothing about audio, if for no reason other than completely different senses and operational mechanisms in the equipment do exist.

Most metaphors that try to equate audio to photography are likely to elicit painful groans from knowlegable audio people.

One big difference is that at the same level of representation, video signals technically  represent five  dimensional (X, Y, depth, color, time) objects while audio signals represent only 2 dimensions (time, amplitude). 

BTW there's a pretty fair technical review of an Intel Nuc audio system here:

http://archimago.blogspot.com/2016/08/measurements-intel-nuc6i5syh-and-audio.html

Re: USB transient noise with external DAC

Reply #69
I can also list some candidates but I have used none of them so don't know if they are trouble-free or not.

Asus Xonar U7
https://hydrogenaud.io/index.php/topic,107822.0.html
They criticized the quality of its headphone amp but it seems that you only use speakers so if you don't mind it can be a good solution.

I have recently purchased ASUS Xonar U7 USB  and use that as external USB DAC solution, mainly with line out output but sometimes also with headphones Sennheiser HD555. When used in WASAPI exclusive mode it does not resample through software and accepts 44.1/48 kHz at nearly equal quality and the same direct mechanisms for both rates as an input (in single speed mode, then it oversamples internally). No problems with that USB solution in Windows 10 in USB 2 mode. Whereas Realtek ALC's "like" 48 kHz more and 44.1 is supported well but through zero-stuffing mechanism, variable sample rate mechanism - source http://www.hardwaresecrets.com/datasheets/ALC898_DataSheet_0.60.pdf , page 15, chapter 7.2.5. So it can be suggested to use SoX or other hq sw resampler to feed those Realteks with "clock native" sample rate (clock rate of realtek is 24 MHz isochronous with 48 kHz bus - page 9 dtto). I have no claims about audibility but given the construction of those cards it may be beneficial to follow what they support best.

Re: USB transient noise with external DAC

Reply #70
I have recently purchased ASUS Xonar U7 USB
Does the U7 still functional as a class compliant device without installing the Asus driver? SMSL M3 should be no problem (it has no dedicated driver after all) but Asus U7 and X-Fi HD have more functions than a simple USB DAC so I am a bit worry about that.

Re: USB transient noise with external DAC

Reply #71
Arnold, thanks for the link on the NUC.  It appears only external USB DAC's were tested.  Perhaps there are no loud pops at his house.  Sorry for the painful groans.  Photography is not audio.  I can post a photo here for you to see.  Audio involves describing something one heard and not the sound itself.  That is the real difference.  Perhaps the operative word in TOS 8 is "subjective".  Different people have different ideas about when things go from subjective and opinion to objective facts.  None the less this world is driven by extremely subjective reviews of many items like audio gear, restaurants, wine and so on.

Anyone interested in viewing my photography send me a PM for information.  It is free to look at and nothing is for sale.   Please don't freak out if you don't like it.

re: Realtek processing of 44.1

I have tried resampling 44.1 to 48 on my ALC283 and try as I might I can't even begin to hear a difference from the native 44.1 support.  Of course the most that proves is resampling 44.1 to 48 is indistinguishable (to me) from what Realtek is doing.  There are a lot of opinions dating back to the AC97 standard where people swore resampling to 48 was a must.  The author of ASIO4All has included that feature in his driver package under a similar rational.  However, AC97 is obsolete.  I still don't understand where the 3,900 empty frames per second go, but in the above posts I recall it was established that bit perfect playback is maintained when output from the digital optical out port is recorded.

Re: USB transient noise with external DAC

Reply #72
The operative in TOS8 is objective support.  There have been quite a few discussions by people looking for loopholes to squirm out of. Let this not be another instance of that.  If you read my contributions to those discussions you'll hopefully understand that I'm not interested in having you prove that your DAC was creating pops.

I'm sure your photography is lovely, but that doesn't give you any more ability to prevent your brain from creating impressions that don't actually exist than my being a musician and trained professional listener. On the other hand, my experience has demonstrated just how fallible the human brain is at interpreting sound. I don't see how being a photographer can even begin to give you this insight.  Have you ever performed a controlled listening test?
Is 24-bit/192kHz good enough for your lo-fi vinyl, or do you need 32/384?

Re: USB transient noise with external DAC

Reply #73
I thought if I could not detect any difference in an uncontrolled test, there was no point to a controlled test.  There are lots of times I think the setup is one way and think it sounds better and then find out I changed it back to the "baseline" but forgot about it.  That's pretty close to a controlled test.

My brain creates all sorts of impressions, but if on Monday I think A is better than B and on Tuesday it is the other way around, and that keeps happening then there is very high probability that I can't tell the difference between A and B.  If I get confused and mistake A for B that increases the chances.  I hope you don't think I am squirming.  I would call that lack of objective support for A and B being different.  That isn't exactly saying there is objective support for A and B being the same, but I am not claiming that.

Being a photographer gives me confidence in my senses and my ability to separate what I want to be perceiving from what is really out there.  It gives me healthy skepticism.  In photography we often say that others are not seeing what the photographer was seeing.  It does not make me god or an expert on audio.  It is totally different from your insight.

Musicians are a whole different ball game.  They have such a good idea of what a certain piece should sound like that you could play back a symphony on a clock radio and they would hear a perfect symphony because their memory overrides the deficiencies.

Again, where does one draw the line between fact and opinion?  If I said I heard a siren from a first responder's vehicle, how much other proof is needed?

By the way I am a retired lawyer and CPA as well.  I was best known for advising on mergers and acquisitions.

Re: USB transient noise with external DAC

Reply #74
That answer says no, you have not performed a controlled listening test. This site has a lot of information about what they are and how they should be performed. Please read them instead of offering up incorrect theories about what the are, what they're intended to measure and how they're performed.  I hope this will be the last time I have to discuss this with you.
Is 24-bit/192kHz good enough for your lo-fi vinyl, or do you need 32/384?

 
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