Is USB straight from a Mac computer to a DAC really that bad?

[sandyk]

3 hours ago, audiophile911 said:

I connect my Chord Quest directly to my Mac Mini; which is dedicated to only running ROON Core; with an AudioQuest Diamond USB and I think it sounds great. 

 Numerous members have found that the standard Mac Mini benefits greatly from replacement of it's SMPS with a Linear PSU such as from Uptone Audio. Even then, further worthwhile improvements are often obtained using an Iso Regen etc.

 Why not ask these questions in the Uptone area of the forum as well ?

 

[sandyk]

42 minutes ago, beerandmusic said:

I have heard this before, but I am not sure I believe it.  Most everyone agrees that the dac gets the digital bits perfectly, it's just that there is noise. 

 That is definitely not my experience, although noise can play a part, the Data is normally received without error.

 The PSU itself also determines how the Audio will sound. Use too many Low ESR filter capacitors in the PSU for example, especially the PSU area powering the OS SSD and Music storage SSD, and the sound can become too bright/HF detailed.

 The same even applies to the external PSU powering a USB Regen, which in itself increases HF detail slightly due to the necessarily small value filter capacitors it uses with it's internal voltage regulators. This is even when powered directly by a 12V Li Ion battery and saving to USB memory . Many members also obtain added HF detail when using the ultra low noise LT3045 voltage regulators to power various items, and for the same reason, which is to increase HF detail and soundstage.

 Some even use a couple of these regulators in tandem for this reason.

(Check other areas of the forum such as Music Servers )

[sandyk]

1 hour ago, beerandmusic said:

so you disagree, so there is no reason to discuss this topic further with you...

we need to have an initial agreement before we can discuss or look further....

 

You don't need to, as it isn't your thread .

[sandyk]

4 hours ago, beerandmusic said:

Also keep in mind liking the sound better does not always equate to accuracy and there may be some emotion and perception involved as well. 

Are you suggesting that one or both of the quoted devices above has forwarded corrupted Data to the receiver in the DAC ?

 If not, according to you, both should sound identical !

[sandyk]

45 minutes ago, beerandmusic said:

 

Any software engineer (or hardware engineer) would state what I have...that the bits are transferred perfectly along with a reference voltage and noise.  I am not referencing potential issues with upsampling. 

 

The Data is sent as analogue waveforms , the shape of the waveforms and voltage levels, as well as the timing is dictated by the front end, and will also obviously look different at the DAC end of the cable which in the case of USB may be <1M long,  or not much more than 5 Metres long,(at which length errors may occur) where the input circuitry (Schmidt Trigger etc.) will try to convert it into a correct

1 or 0.
With a less than perfect input waveform, the receiver's Schmidt Trigger etc may toggle at a slightly different part of the waveform, resulting in some timing variations.

This also applies to Coax SPDIF where they may use a Schmidt trigger (e.g. 74HCU04)

 to try and " square up" the waveform.

 

 I get it that you don't like what I am saying, so now feel the need to childishly revisit every recent post I have made as payback, on any subject ,and click Disagree, like in the case of the recently banned Charleslatham who  felt the need to click " laugh" on every post by 2 members.

 

See for example

#528

[sandyk]

41 minutes ago, beerandmusic said:

no, you have childishly clicked disagree with every post i make, without offering any reasoning, even on posts that i never made a statement that you can disagree with.  In one such post I said I am trying to understand the logic of something, and that is all i said in that post, and you clicked disagree with.  There was NOTHING in the post to disagree with, i was asking a question.  You were just being annoying on purpose.  Next time read what i write, and if you do not understand what I am asking, then either don't respond, or ask for clarification, but don't disagree with a "question" i make when it is posed as a question.  You were just trying to be annoying and you know it.   Instead of just squabbling with me, or following me around, just put me on ignore, and I will ignore you as well so we can both go on peacefully. 

 I gave you an indepth explanation in post #49   but you have shown that you simply aren't interested in  any explanations that are in disagreement with your own P.O.V.  I only click Disagree(e.g. #36) when I have a problem with the content of a post , which is often based on actual hands on experience in that area as an  experienced DIY person who has constructed several DACs and has also done indepth investigations in the USB Audio area , including this old thread.

https://www.computeraudiophile.com/forums/topic/13905-continuing-pursuit-of-power-supply-improvements-and-improved-dac-performance/

 Your 5  "Disagrees'' ) appeared in quick succession showing that you quickly went through all my recent posts in different threads specially , just as another member who has already been banned a couple of times already is presently doing.

[sandyk]

8 hours ago, davide256 said:

8 hours ago, 6aardvark9 said:

 

Quite the opposite for me... I consider jitter to cause digital glare and top end harshness

tended to find this linked more to source hardware and power supply quality. Of course a PS Audio Dlink III could make any source sound like that

 

what I've experienced is that timing degradation in the source causes background instruments to lose definition

 I agree.

[sandyk]

52 minutes ago, Miska said:

Third aspect is that if your source content is 192k hires PCM, then if the DAC runs at 192k, there is no space at all for transition band between Nyquist of the source and first image band.

 

 However, in the real world there is very little genuine musical material beyond around 55kHz ,with that already at quite a low level,  and images of any musical material above that will be at extremely low levels. The microphones used in the attached by Barry Diament were only 1dB down at 40kHz which is a wider bandwidth than most .

[sandyk]

7 minutes ago, Miska said:

 

Try with Sanken CO-100K

 

Also with Sennheiser MKH-8020 you get pretty wide bandwidth for recording cymbals and such.

 

And not necessarily so low levels even at 100 kHz:

http://www.cco.caltech.edu/~boyk/spectra/11.htm#b

 

And of course with electronic music, or music using synths, you are not limited by microphones, you just get what the synthesizer algorithms create in digital domain.

 

Miska

 I have previously posted the same spectra above, however, as I stated , very few recordings have much genuine musical content above 55kHz due to the actual microphones used.

 Do you have you any recordings like you mentioned that have such content that you can post a copy of their frequency spectrum ?

 Have you heard anything about the Laser microphones that were mentioned some years back, with their extremely wide bandwidth  ?

 

Alex

[sandyk]

43 minutes ago, Miska said:

That is sort of irrelevant for the topic here though.

Agreed

 Neither do I wish to get into discussions about the need for the substantial additional expense of converting everything to DSD which most consumers do not need, or the general public even know about.  How many members even have speakers that can do justice to much more than 20kHz, let alone worry about phase shifts at 50kHz or get the best from DSD  especially when using Hypex amplifiers as you mentioned.?

At the moment, it has been shown by John Dyson that it may be more rewarding to clean up the damage done with poor mastering techniques at 16/44.1 which can often sound like high res. when properly mastered without a lot of editing/mixing .

 Perhaps we need more " direct to disc "  type material using today's vastly improved electronics ?

 

[sandyk]

32 minutes ago, Miska said:

What kind of DAC do you have? Because SDM (DSD) converters have way more than 95% market coverage in audio ADC and DAC. Also your mobile phone's microphone is a "native DSD microphone", although very few even know about it.

 That is misleading. None of them do what your program does, as well as the need for a very fast processor PC.

I doubt that my i7 Intel processor would even handle this too well. Neither are most speaker systems good enough, let alone the amplification area , although my Class A Preamp/HA  with it's 1.5mHz -3dB bandwidth and my 15W/Ch.  Class A P.A. certainly are.

 

 I do however applaud your initiative to try and get the very best out of normal recordings for those who have the technical ability and wallet to afford it. More research like this is needed.