[jacofman]

So to summarize what you've said:
 
1. Both the M2Tech HiFace DAC and the KingRex UD384 "WILL" play my 24/192 files directly from the USB out on my MBP without any additional equipment needed because they are both USB Audio Class Two compliant.
 
2. The Asus Xonar Essence One is NOT USB Audio Class Two compliant, and therefore would not serve much purpose to me if my goal is to play the 24/192 files as simply as possible.
 
3. I could not use either one (M2Tech or the KingRex)  in my high end room system because the Sony Blu-ray player only has an optical (toslink) out and neither one of the two DAC's mentioned has an optical "in".
 
4. For computer use, they are both fine and I could send the "computer-based" hi-rez files to my home system via each of their respective output formats--mini to RCA for the M2Tech and "RCA to RCA" for the KingRex--or, to my tube headphone amp via the same connections. 
 
This might be a stretch, but do you know either one of these units and do you know how they actually sound? I am going to assume from the reviews (no personal experience) that the KingRex sounds better. It seems to be designed for an audiophile audience. Plus it has the USB to S/DIF converter to send  hi-rez files to other DACs in case I want to get a separate DAC for my home system.
 
Thanks for teaching me about this complicated, highly technical world of digital audio.

 

[MrScratch]

1. Yup, that's how they work.
 
2. That's my assumption, in fact I'm not sure of that as I've never used a Essence One and I can't find any info about OS X support. Asus doesn't advertise it, they just say that "The Essence One supports Mac OS X 10.8 or later version without any driver needed." So it seems I was clearly wrong, a review on another site has demonstrated that the Essence One is USB Audio Class 2 compliant as Mac computers recognise it instantly allowing hi-res sampling rates up to 192KHz/24bit.

I don't know if I can post the link to the review, however a screenshot clearly shows the Essence One recognised in Audio MIDI Setup as "Speaker" with all the supported sampling rates (from 44.1KHz to 192KHz @ 16&24bit).
 
3. Right.
 
4. You are right again.
 
(5.) Sorry but I never had the chance to listen any of them so I can't comment on that. Anyway, now I stand corrected: you can get a Xonar Essence One and live happily with that.

It should be noted that the reviewer said he used a MacBook Pro Retina with Mountain Lion (10.8.x) and you said you have a late 2011 MacBook Pro which was shipped with Lion (10.7.x). If you decide to get a Essence One and your OS doesn't recognise it, you can buy the latest OS directly from the app "App Store" in your Applications directory for $ 20. It's a huge installer (about 4 gigs) and it will take about 45mins to complete the update. Don't worry, the update won't format the hard drive and all your files will be still there (like in Windows systems with a multi-parititioned hard disk and a OS-only partition).

 

[jacofman]

MrScratch, thanks for all your help. I've decided to get the Asus Xonar Essence One Plus Edition (http://www.asus.com/Sound_Cards_and_DigitaltoAnalog_Converters/Xonar_Essence_One_Plus_Edition/#overview)
as my final choice. It has great features, supposedly great sound (that one can change even further by "rolling" the op-amps in the kit they include) from audiophile review sites, and the price is right. I'll report back when I get it what it "sounds" like. Thanks again to all of you who helped me understand the technical stuff so that I could make an informed decision. That's what this forum is all about, right?

 

[jacofman]

I had another observation which leads to a question. I noticed that in playing some hi-res files (24/192) through the Fiio E17 and my AKG K702's, the music sounded very different when listening to the USB output vs the S/PDIF optical output. The optical had more of the room ambience on acoustic music, more defined dynamics,  more detail in the mids and highs, and each instrument had more body and weight than it did playing the same cuts through the USB output.
 
1. I wondered if I was losing my "golden ears" and my mind and just making up these differences;
 
2. There are actually differences explained by the fact that in S/PDIF you're getting the pure digital signal and bypassing the MBP's internal DAC and amplifier. You're hearing only the Fiio DAC and amp, both of which should theoretically should sound better than the MBP's or there would be no reason to buy and outboard amp and DAC.
 
3. It's strictly a function of the "sound" of the Fiio's different inputs. On another DAC, they might sound the same or the reverse of what I described above.
 
4. The "USB DAC" phenomenon is just a marketing ploy to get people to buy DACs but S/PDIF has always sounded better for some reason that I can't articulate and don't understand.
 
Any ideas?

 

[thrand1]

I'm not as well versed on the technical side of things, but in most cases, when using the USB connector, a USB "receiver" (Tenor TE7022L) has to be used to translate the signal to something recognizable by the E17 DAC. Depending on how the FiiO is implemented (one review seems to say there is even another transceiver chip between the Tenor USB receiver chip and the DAC), the S/PDIF input signal might not have to go though "as much"/any transformation before being fed to the DAC. So having an extra "chip" in the path could lead to some differences in perceived signal level, volume or otherwise.
 
One thing I would point out- regardless of whether you use USB or SPDIF, your Mac is not doing any internal decoding or amplifying- both methods should deliver a raw digital/bitstream signal to the FiiO. One might have a higher volume level than the other after conversion, but I have no way of verifying that.
 
What you're noticing is often reported by users of DACs with multiple inputs- there is a DAC from Chord (the Qute, maybe?) whose entry level model is reported to sound much better on the SPDIF input versus the USB input. But there may be DACs where the USB input has had more attention to it so it might be better than the SPDIF, etc etc.
 

 

[brhfl]

Quote:

One thing I would point out- regardless of whether you use USB or SPDIF, your Mac is not doing any internal decoding or amplifying- both methods should deliver a raw digital/bitstream signal to the FiiO. One might have a higher volume level than the other after conversion, but I have no way of verifying that.

It is worth noting, however, that if the software being used doesn't automatically switch the output sample rate, and the output sample rate differs from the source media, the Mac will resample the audio, on the fly. I know the importance of switching this was already stressed, but I think it's a bear worth repeating. Rowr!

 

[MrScratch]

I took the time to make some tests.
I've tested USB and TOSLINK inputs with my iMac. I used iTunes as my main source with ALAC files ripped in XLD at the original sampling rates of the CDs.
The test tracks I've used are as follows:
Mirrorball - The Seldom Seen Kid - Elbow
The Night Will Always Win - Build a Rocket Boys - Elbow
Hope - Cult - Apocalyptica
Coleen - Great Vengeance and Furious Fire - The Heavy
Shun - Sanmon Gossip - Shiina Ringo
I Believe - Keep The Faith - Bon Jovi
Give Life Back To Music - Random Access Memories - Daft Punk

All the tracks are sampled at 44.1KHz @ 16 bit.

First of all, I made sure the Audio MIDI setup would keep the same sampling rate while I was switching back and forth between USB and S/PDIF inputs. Since on S/PDIF the master volume is set at a fixed value, I obviously maxed out the USB master volume as well.
 
My test setup:
- iMac -> TOS (L12) -> FiiO E17 @ +0dB;
- iMac -> USB (bundled cable) -> FiiO E17 @ +0dB;
- iMac -> TOS (L12) -> FiiO E17 -> LO Bypass (+L7) -> FiiO E12;
- iMac -> USB (bundled cable) -> FiiO E17 -> LO Bypass (+L7) -> FiiO E12.
 
Aaaand... I didn't find any difference worth mentioning. On a track in particular (Coleen) I thought the S/PDIF had the edge in clarity, however further listening proved I'm unable to tell a damn difference.
Plugging the E17 in the Apple Keyboard USB socket didn't make any noticeable difference.
 
@jacofman: Have you tried different USB ports? Did you set the two outputs at the same sampling rate (96KHz/24bit in your scenario)?

 

[jacofman]

Thanks so much for taking the time to test out my impressions (hallucinations). You were quite thorough and as suspected, there were no discernible differences between the different digital formats. You played a variety of different types of music, and that's good. What I heard was subtle, but definitely felt like a small difference in favor of S/PDIF. The volumes were equal and the resolutions were the same across the board. Nothing changed except the form of output to the Fiio. I wouldn't worry about it. It's so subtle it's not worth pursuing. Another weird thing that happened is that sometimes (rarely) the Fiio didn't show up in one of the two USB ports on my MBP. The one closest to the front of the computer consistently registered the Fiio, and the one closest to the back of the computer occasionally wouldn't show it in the list. Perhaps it was just a bad connection or the USB cable (which came with the Fiio) didn't make a solid connection. 
 
Have you given any thought to the idea that the USB cable makes a difference? Some people (Moon Audio) are selling "audiophile" USB cables. You think it's a bunch of crap, or is there something to it. I'm a firm believer in the notion that cables make a "huge" difference in my home audiophile rig. Night and day differences sometimes. Any thoughts?

 

[MrScratch]

I won't question the influence of this kind of cables on the sound, however I think it all comes down to how much this difference audible.
Sometimes the differences are so subtle that they might be really hard to notice. It all depends on how much you value the little increments in SQ.

 

[Billheiser]

Subtle differences might be due to small volume differences. Unless you used precise (measured) volume matching, source x will tend to sound better than source y if it's even a hair louder.
"...had more of the room ambience on acoustic music, more defined dynamics, more detail in the mids and highs, and each instrument had more body and weight " -- that would also be what you experience with slightly increased volume.

 

[Dev Caj]

I know this is from years ago, but I tried doing this exactly and the output states 24 bit yet my Fiio still says 16bit 48k. I dont know what to do here or if its the new MacBP 2016. Its apples newest model and im using the VOX player to play the FLAC file. Im stuck. Is it my headphones? Is it the USB cord? please help!