Sure, that's possibly true - but what it demonstrates is a chasm of difference across different XMOS implementations ie. the commonly available cheap-and-nasty Chinese XMOS boards are a long way behind the well implemented XMOS boards (I will give examples later).
There's also a difference between different versions of the XMOS chip, as mentioned by forum member qusp in 2013 -
http://www.diyaudio.com/forums/digital-source/233926-xmos-usb-384khz-2.html#post3451788
And sure, a potential solution to getting better SQ than these cheap units may well be to use an implementation which converts the cheap boards' (jittery) I2S output to s/pdif, as an intermediate transmission format ...
but I consider this something of a kludge, or a workaround, not a true solution. And it leads novices to think that s/pdif is somehow a "magic bullet", whereas it's really a legacy digital transmission format left over from the 1980's which we should be aiming to replace (with LVDS, for example).
The elegant solution, for just a few dollars more, is to use a quality USB interface in the first place, for example;
- JLSounds (XMOS based) - 67 Euros
- Lorien's WaveIO (XMOS based, extensive reclocking) - 99 Euros
- genuine Amanero Combo384 (Atmel based) - 99 US dollars
But in this particular situation, the point is moot, anyway; dabenza has decided to buy an SMSL M8A, which has a well-regarded integrated XMOS Xu208 chip (not a separate card), good clocks, and decent LDO regulators. Various reviews on the web indicate that this is a decent implementation of the XMOS USB interface.
To be clear, your M8A's XMOS decoder outputs raw I2S, which directly feeds the DAC input. There's no s/pdif involved; not externally, not internally.
Hi guys. I received the SMSL M8A two days ago. With my macbook, it was detected inmediately. Used it with Audirvana player. The sound? Well, very nice, detailed, opened,... very nice indeed.
BUT
The USB started having some clicks from time to time. This morning my wife was listening to music, very low volume and, suddenly, the speakers made tremendous noise. It happen again this afternoon while I was there. Terrible. I just hope the thing didn't destroy my speakers. I have to say I don't know if the configuration was wrong, but something like that should not happen at all. It was working on interger mode 1. But, certainly, I think it should go back to amazon and keep on searching.
I considered increasing the budget and considering the Topping DX7, as I'm not ready to DIY yet. The AUDIO-GD NFB-11.28 is another option. I don't know what you think guys.
BUT
The USB started having some clicks from time to time. This morning my wife was listening to music, very low volume and, suddenly, the speakers made tremendous noise. It happen again this afternoon while I was there. Terrible. I just hope the thing didn't destroy my speakers. I have to say I don't know if the configuration was wrong, but something like that should not happen at all. It was working on interger mode 1. But, certainly, I think it should go back to amazon and keep on searching.
I considered increasing the budget and considering the Topping DX7, as I'm not ready to DIY yet. The AUDIO-GD NFB-11.28 is another option. I don't know what you think guys.
I'm using an external lineal power supply too. I'm investigating about it because I'm really bothered. It might be as well my own audio configuration inside audirvana. I'm trying with another computer, another set of speakers and so far so good. But I cannot say what is causing the problem yet. I'll have a look for a couple of days and, if not satisfied, will be sent back. It is a nice piece of gear though. Good looking and sounding very good.
Sounds like a driver issue, specifically in your case, how the Mac XMOS driver interacts with Audirvana. I remember in the early days of the XMOS device there were reports of clicks/pops, especially with the Raspberry Pi.
Maybe this Audirvana configuration information is relevant? -
XMOS USB Audio 2.0 Mac OS Hog and Integer Mode Support - XMOS embedded processors. Heart of XMOS technology, XCore.com
Or maybe worth doing an OS update on your Mac?
Or in desperation, I saw on the web that someone put a USB 2.0 hub between their Mac and the XMOS device, which overcame a USB 3.0 port issue.
Maybe this Audirvana configuration information is relevant? -
XMOS USB Audio 2.0 Mac OS Hog and Integer Mode Support - XMOS embedded processors. Heart of XMOS technology, XCore.com
Or maybe worth doing an OS update on your Mac?
Or in desperation, I saw on the web that someone put a USB 2.0 hub between their Mac and the XMOS device, which overcame a USB 3.0 port issue.
So LF, from reading your posts, I am guessing the M8A DAC I have would not benefit from an external USB to SPDIF or other format converter. I am aware of the Singxer SU1 and some folks are saying there is an improvement. Probably at this DAC price point an external converter won't make that much of an improvement.
Thanks for you reply
Thanks for you reply
The price-point of a DAC hints at how good its USB interface may be, but is not the final determinant. Going by reviews on the web, the M8A's integrated XMOS is well regarded, but maybe not great. Most likely better than those $50 Chinese plugin XMOS cards.
So I would speculate that the $70 converter that ttan98 mentioned is unlikely to achieve an improvement in this case ...
but the $400 Singxer SU-1 - sure, that's likely to get you an improvement. But would you add a $400 USB upgrade to a $250 DAC? Seems out of proportion to me.
If you had such a total budget - $650 - I would look at a higher level of DAC, and at that price point you can now be more confident the USB interface will be very good.
The entry-level Denafrips DAC springs to mind -
ARES - DENAFRIPS
Back to the M8A, if you want to upgrade its USB performance, ideally you would aim to add one of those high performance USB interfaces I listed earlier ...
but it can be difficult to combine DIY products with full commercial products - the M8A does not easily accommodate an add-on card - some fine soldering and hacking would be involved.
That's why I think the ES9028PRO DAC that dabenza mentioned in the first post is such a good proposition - to the base price of US$270 add a genuine Amanero USB card at US$99 (open the lid and plug it in) and for a total outlay of US$370 you have the latest ESS DAC technology with one of the highest regarded USB interfaces, cased up with what appears to be good power supplies.
Thank you very much Linuxfan for so many good explanations. I have tested the M8A a bit longer, because there must have been something wrong with the configuration. And so it was. In Audirvana I had checked the forced upsampling, and, after I unabled it, there had been no problems any more. I don't need upsampling. I'm happy with my flac files just as they are. In the meanwhile, I checked other DACs, this one is also from a chinese manufacturer, but sounds quite impressive, and can be bought at a french online store, with fair support and the possibility to return it without so many problems. The model is this:
AUDIO-GD NFB-11.28
and looks quite good. Bought here in Europe, at Audiophonics : Achats de Produits Hi-Fi Audio Electroniques et DIY - Audiophonics, costs 400€. Is quite a bit above my budget, but I'm here to take the risk. My wife wouldn't have to know. What do you think?
AUDIO-GD NFB-11.28
and looks quite good. Bought here in Europe, at Audiophonics : Achats de Produits Hi-Fi Audio Electroniques et DIY - Audiophonics, costs 400€. Is quite a bit above my budget, but I'm here to take the risk. My wife wouldn't have to know. What do you think?
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I bought a low cost ($50) USB DAC once and found it was reliable, very clean sounding but could be a little harsh in the treble if the rest of the chain was already leaning that way.
One set of comments I found helpful at the time from somebody called 'watchner' on head-fi last year, which I kept and I will offer here:
1. Implementation is just as important as the specific DAC chip technology. Don't pick something just because it has your favorite species of chip.
2. Remember that almost all modern recordings are made using Sigma-Delta AD converters before you get too crazy purist about the superiority of R2R (unless you're only going to listen to digital recordings from the last century, and no modern re-masterings).
3. R2R vs Delta-Sigma is most importantly about what a given designer is most comfortable with. They're both just tools, capable of glory or disaster in the right or wrong hands. If a designer does her best work using R2R, then you may have a solid reason for preferring R2R from that vendor (e.g. Schiit). On the other hand, if a given designer pushes the envelope of DS design, that's probably the better product from that vendor (e.g. NAD Master Series).
3. For R2R DACs that use DSP filters, the filter is really the secret sauce that has the biggest effect on the sound (aside from the analog output stage). There are real, measurable differences between IIR and FIR filters in the realm of phase and impulse response. How much this is audible is a different question. But it is real.
4. Except for the cheapest gear, old gear, or disastrously crappy connections, jitter is probably not worth worrying much about now. The difference between 500 picoseconds and 100 picoseconds of jitter in the audio band is more about epeen and bragging rights than anything audible.
5. Pay more attention to the analog stage than the chipset (unless you need/want DSD). A beefy analog stage with good power supply and isolation, coupled to a ho-hum DAC chip, will beat a razzle-dazzle expensive DAC chip coupled to a ho-hum analog stage.
6. DACs are not turntables or tape decks or tuners or other highly flawed, distorted, electromechanical analog sources, where the difference between the best and the worst is both huge and costly. $99 DACs can be perfectly listenable, regardless of chipset, with only minor flaws. The same wasn't true of budget tape decks or budget turntables. So keep things in perspective.
One set of comments I found helpful at the time from somebody called 'watchner' on head-fi last year, which I kept and I will offer here:
1. Implementation is just as important as the specific DAC chip technology. Don't pick something just because it has your favorite species of chip.
2. Remember that almost all modern recordings are made using Sigma-Delta AD converters before you get too crazy purist about the superiority of R2R (unless you're only going to listen to digital recordings from the last century, and no modern re-masterings).
3. R2R vs Delta-Sigma is most importantly about what a given designer is most comfortable with. They're both just tools, capable of glory or disaster in the right or wrong hands. If a designer does her best work using R2R, then you may have a solid reason for preferring R2R from that vendor (e.g. Schiit). On the other hand, if a given designer pushes the envelope of DS design, that's probably the better product from that vendor (e.g. NAD Master Series).
3. For R2R DACs that use DSP filters, the filter is really the secret sauce that has the biggest effect on the sound (aside from the analog output stage). There are real, measurable differences between IIR and FIR filters in the realm of phase and impulse response. How much this is audible is a different question. But it is real.
4. Except for the cheapest gear, old gear, or disastrously crappy connections, jitter is probably not worth worrying much about now. The difference between 500 picoseconds and 100 picoseconds of jitter in the audio band is more about epeen and bragging rights than anything audible.
5. Pay more attention to the analog stage than the chipset (unless you need/want DSD). A beefy analog stage with good power supply and isolation, coupled to a ho-hum DAC chip, will beat a razzle-dazzle expensive DAC chip coupled to a ho-hum analog stage.
6. DACs are not turntables or tape decks or tuners or other highly flawed, distorted, electromechanical analog sources, where the difference between the best and the worst is both huge and costly. $99 DACs can be perfectly listenable, regardless of chipset, with only minor flaws. The same wasn't true of budget tape decks or budget turntables. So keep things in perspective.
I just wanted to finish this thread with my final purchase. Ive been very busy, so I couldn’t really sit down and listen for enough time. I bought the chinese Audio-gd NFB 11.28. It’s not any of the dacs listed in the first post, but it is chinese. when you open it, and you should, to try the different filters that can shape the sound to your convenience, you see a very well built gadget, soldering is very neat, the layout is perfect, materials used seem to be top quality. Overall it doesn’t look chinese at all. The sound is very satisfactory, but, as I said, the possibilities of filtering must be tried. It does change the overall sound. it is a very good headphone amp, it has 12db gain switch and the volume control for me is a must. I’m quite happy with the purchase, although it went a bit above my budget.
I want to thank you all for your replies and advice.
I want to thank you all for your replies and advice.
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