|
DACs
Dec 3, 2017 17:26:34 GMT
Post by Mr Trev on Dec 3, 2017 17:26:34 GMT
From another thread - I didn't want to derail: The SMSL Sanskrit 6 has a WM8740 DAC chip . There is also the pro version which has the 4490 chip. These 2 chips are not far apart in performance, the 4490 can go a little higher in sampling frequency. I see no profits (only downsides) in going above 24/192. The Shitt modi (non multibit) also has the 4490 chip. The modi multibit has different chip. Measurement wise the 4490 chip is the better one. That is except for 'noise levels In order to make these noise levels audible you would have to listen at 150dB SPL peaks though. But it is not as much about the used DAC chip but more the implementation. What filter is used both digital as well as analog. What is the accuracy of the analog filter compomenents. This may result in a wide range of measurable differences. Some bordering on audible ones, some inaudible and some quite audible. The Modi MB is measurably rolled off in the upper treble. Depending on your age and used music this may well be audible on 'direct comparison'. When someone held a gun to my head and told me to choose between the MB and 4490 I would choose the 4490 variant. This decision would be based on measurements. The measurement differences are well below the 'audible barrier' for most people. I think I would be perfectly happy with the SMSL. Turns out I've been thinking about getting a desktop DAC. I've just been using my Fiio X3 (and trying the Cayin N3) for this purpose. I have been wondering for a while if it really is worth getting a dedicated DAC, considering the quality and feature set of the DAP/DAC units out there. My one big issue with using a portable unit is that I haven't found a way to keep the battery from getting topped off constantly - which I've read isn't exactly a good thing. Anyhow, since Frans brought it up, a few questions… Why do you say only downside to over 24/192? Does this mean I shouldn't be bothering to upsample my music to DSD1024³ in DAPhile A device I've been looking at is a Topping D30. It uses an old CS4398, but does have all the type of inputs. The coax would let me use the digital out of the X3, and turns out it'll be really easy to switch to optical out on DAphile. I've read the SPDIF is far better than using a USB, but isn't Toslink full of its own problems? Another bonus of the Topping is it's cheap and if going off how well my NX1 amp performs, could be a great value/$$ prospect - it has some good reviews on HF. (regarding cheap, are any of those DIY Sabre units on eBay worth the money) Speaking of USB, another device that has me interest now too is the iFi nano black edition. It doesn't have the digital inputs, but has an onboard USB purifier. Are USB cleaners actually worth the time or would I still be better off with SPDIF? Along with the iFi there is a few other portable DAC/Amps I'm looking at there too (Peachtree Shift, iBasso d12) that are Sabre based and have the ability to turn off charging Cheers, for now
|
|
solderdude
Administrator
measureutternutter
Posts: 4,881
|
Post by solderdude on Dec 3, 2017 21:11:20 GMT
Well there aren't many real- world recordings around with actual 'info' above 40kHz. Sure instruments can have high harmonics. Certain measurement micrphones can also reach those frequencies. These aren't used with 99% of the recordings out there though. The 'signals' one sees above this frequency (when present at all) is noise. Why would one want to reproduce inaudible noise at the expense of double the bandwidth and memory usage and possible speed problems ?
There aren't many DAC's around that have a real world resolution of 24 bits nor are there recordings that reach that. Why advertise 32 bits ?
Upsampling already happens in all DS DAC's to almost DSD frequencies. In a lot of multibit DAC's upsampling is used as well so reconstruction filters can be higher up in frequency. When you upsample a 44/16 signal you still get the infamous 'ringing' at around 21kHz and bandwidth is still limited to 20kHz. This ofcourse depends on the used algorithm/filter. The only 'advantage' one gets is the design of the final analog filter can be much simpler (cheaper)
On the other hand when any of these techniques floats ones boat and they like the sound then I am all for it.
TOSLINK arguably has a high level of jitter unless real fiber optics are used instead of the familiar plastic light-sewer cables. In fact the signal going through TOSLINK = S/PDIF but 1's are 'light on' and 0's are 'light off'. It's the receivers that cause the jitter problems here. As S/PDIF is both clock and data the clock recovery may have to be a bit more resistant to jitter.
Coax S/PDIF also is a combined signal. It carries both the clock and data and therefore can be jittery depending on the transmission line between the source and receiver. You can electrically isolate S/PDIF by using transformers but these are bandwidth limited and thus can introduce data dependent jitter. Let's just say that S/PDIF format is greatly overrated in the audiophile community. AES EBU is the same except the signal is balanced.
Most modern DAC's have excellent jitter rejection. I am quite convinced jitter is inaudible. Jitter is a timing issue resulting in an amplitude being VERY slightly different. These level differences are far below the audible threshold. For 'products' of -120dB to be come audible you would have to be listening at deafening SPL's of 130dB peak or more. The time period (years ago) where jitter reached problematic levels due to poor (cheap) implementations is long ago anyway.
Lots has been written about USB not being suited for audio and the problematic 'quality' of the electrical signal. Most people seem to think the USB signal is directly related to the audio (as if SPDIF is a transmitted SPDIF signal) It does not work that way. Supposedly it took Schiit 5 generations to finally get USB 'right' so it does not need polishing at the input any more. Does this mean USB was not a problem to begin with ? Are all USB receivers crappy ? Are other manufacturers not able to get USB 'right' ? In some cases some electrical isolation can be useful as nasties in the PC can enter the audiopath.
I am quite certain though golden eared people or manufactures of miracle boxes will not agree with me at all.
|
|
|
DACs
Dec 3, 2017 23:25:17 GMT
Post by ronzo56 on Dec 3, 2017 23:25:17 GMT
I'm certainly not golden eared whatever that means to people. Having said that, the Schiit Eitr does make an audible difference with the USB from my cheap Walmart (Dell) laptop when I use it with their Modi Multibit. As in I prefer the sound out of the combination. Only reason I can think of is the electrical noise from the computer is isolated. Wasn't that the supposed issue with USB back in the day? I've never heard jitter to cause audible differences in anything I've heard or owned, unless it was just a cheap piece of junk. But then it could be a number of issues causing the poor audio quality. My two cents. Which is probably what it's worth.
Edit: I've owned several miracle boxes and decrapifers. Minimal differences if any. The Eitr is different IMVHO.
|
|
solderdude
Administrator
measureutternutter
Posts: 4,881
|
Post by solderdude on Dec 4, 2017 0:15:00 GMT
I have not had the pleasure of testing the Eitr (nor any decrapifiers). Use 2 USB DAC's but only for measuring headphones so don't listen to music using USB DACs at all.
The ultimate test, however, is performing a blind test. Have someone else plug in the DAC directly or via the Eitr in a random order and then try to determine what is with and without. When there are clear differences a 100% score should be feasable. I understand it is not very practical nor useful when people hear clear differences anyway but still it can be highly educational/entertaining.
I have no idea why a DAC should sound any different unless something in the USB implementation of the original DAC is done 'wrong' and the Eitr somehow corrects that. Not saying it can't be different, just that I can't see why.
Maybe the Dell has a lot of nasties on the USB port ground which is not entering the DAC by isolation from the Eitr any more. In that case though I would expect to hear soft weird sounds coming from the DAC without the Eitr and a clean signal with it. As most DAC's mute their outputs when 'paused' (to lower output noise or 'clicks') chances are you could hear a 'dirtier' signal with really quiet passages yet perfect silence when 'muted' In that case isolation could improve 'cleanness'. If that is the case it is not due to 'better' USB handling but simply isolating in which case other isolators should be able to reach the same level of cleaniness.
The whole 'reclocker/conditioner/re-packaging' USB cleaners won't do much with any modern DAC's but may be of help with poorly implemented vintage designs perhaps.
|
|
|
DACs
Dec 4, 2017 1:41:17 GMT
Post by ronzo56 on Dec 4, 2017 1:41:17 GMT
Good idea Frans! And as I have a temporary house guest I’ll give it a try over Winter break. The Eitr as I understand it is Mike Moffet’s different approach to USB. The scientific method will hopefully determine if the placebo effect is in effect. Results to follow.
|
|
|
DACs
Dec 4, 2017 3:59:16 GMT
Post by Mr Trev on Dec 4, 2017 3:59:16 GMT
Most of the complaints I've read about USB audio seem to be of the electrical isolation variety (galvanically isolate the power pins, etc) I've only had a chance to use USB on my end and for the record I can't say the same song sounds any different played over USB into my X3 running DAC mode versus playing from the X3 directly (I should also point out I'm not using those "dedicated" audio memory cards Sony make - do they still even exist, I know some people would swear they sounded better).
I think maybe the bigger concern with USB is the receiver chips used. For whatever reason the Cayin N3 would always end up sounding like a dirty vinyl rip on my systems. I've tried changing driver settings, even bought a new USB cable and nothing helped. Sent it back for a RMA and of course it worked perfectly at the dealer's shop. The only thought I have left is the receiver chips (or something else hardware related) just wasn't capable on my laptops (odd since I had the same problem on 2 very different spec'd laptops using 3 different OS)
Another thing that had me wondering about the N3 is the AK4490 chip itself. I have read quite a few complaints about how they have a tendency to "pop" when switching sample rates (it's not just the AK, but they seem to garner the most complaints). I can confirm this happened to me - I like making playlists and often end up with 44.1 and 48 khz files playing together. I don't know if that's an inherent issue with the chip itself or just the implementation (I know the newest Sabre has/had some sort of bug that would also make a loud pop when switching rates)
|
|
solderdude
Administrator
measureutternutter
Posts: 4,881
|
DACs
Dec 4, 2017 9:42:08 GMT
Post by solderdude on Dec 4, 2017 9:42:08 GMT
Making a good DAC that ticks all boxes isn't something simple. It's not just a matter of picking available parts and slapping them all together on one board as the application manual suggests.
There are lots of things to consider. Adaptive or Asynchronous 1 master clock or 2 master clocks. types of inputs. Choice of available USB receivers, coax receivers, optics. Galvanic isolation and how to do this (optics or magnetics) Maximum sample frequency PCM and or DSD Digital filter choices as in fixed, adjustable, which type, which brand. Standard or custom. What does one want the customer to adjust Display ? menus, buttons, muting, how to handle errors, how to handle 'silence' and offsets. What to do when a song is suddenly stopped ? Which DAC chip to use. licenses, agreements with manufacturers. Post filtering. line stages, balanced, single ended. SPDIF out ? Power supply... simple or elaborate. USB fed or not. PCB design(er) materials used.
Yes, almost any manufacturer can grab a single do-it-all chip and make a simple PCB but that's not a DAC.
In the case of USB it is important how to 'handle' the incoming data packages. When adaptive (driver less) how to get the DAC clock to stay constant and still match the data speed flow without buffer over or underruns. Some DACs have a more elegant solution than others. One may be more audible others less so.
Basically the trick is to clock out the music signal with a constant speed without any fast 'corrections' which may be needed when the dataflow is faster or slower than the source is handing data. When corrections are often needed and the DAC solves this by instantly lowering the output clock speed of the DAC in a certain rythm or that is done almost 'stepless' and very slowly makes a difference. This is not a USB problem but rather how the receiver manufacturer solved his problems. These days not such a big problem any more but in the beginning it was.
In case of the X3 the DAC doesn't have this issue. The clock for data and DAC chip are the same and constant which is way simpler than using 2 clocks that have to 'synchronise'. Asynchronous works better for USB as the PC is 'told' to speed up or slow down datapackes and so the DAC chip can remain at a constant speed.
Then there is data handling and how to handle errors and which filter one uses, mostly based on (flawed) thinking of the designer. One does not want to hear 'clicks' or experience (small) problems or weird issues. The DAC has to perfectly communicate with different software, hardware and circumstances and is quickly replaced by another one if you don't have everything sorted out.
Then there is support. The thousands of questions people will and can ask when something doesn't work as desired. Then there is rules and regs and things one has to comply to with these kind of devices.
These are the reasons there is no G1217 DAC as I simply lack all the expert knowledge to make one the way I would like and fully develop it. Not that I would not be able to make a good DAC but simply the time it would consume to sort it out and prototype it (no experimenters board here) Would have to quit my job and dive into it for a long time.
Simply using the familiar 'standard' chips found in most sub $300 DAC's and call it a day is not my style. could whip up something like that in a day or 2 but would not offer anything the zillion Chinese DACs not aslo offer and would become way too expensive when made in small Qty's.
|
|
|
DACs
Dec 4, 2017 20:09:55 GMT
Post by Mr Trev on Dec 4, 2017 20:09:55 GMT
OK, so this may be a stupid question, but… if I keep using my X3 - or other portable unit - as a DAC is there anyway to keep it from getting charged (short of removing the battery)? I initially thought it might be as simple as cutting the power leads but seems to be essential for the handshake or whatever the devices need to do. Maybe a switch on the power lead so once the connection is made the power can be cut and let the DAC to use its battery? Or am I SOL unless the device is designed to disable charging
|
|
solderdude
Administrator
measureutternutter
Posts: 4,881
|
DACs
Dec 4, 2017 22:54:58 GMT
Post by solderdude on Dec 4, 2017 22:54:58 GMT
The battery has a limited lifespan anyway as it is Lithium based. When the battery dies open it up and put in a new one.
|
|
|
DACs
Dec 4, 2017 23:53:13 GMT
Post by Mr Trev on Dec 4, 2017 23:53:13 GMT
OK, but have you tried to order a battery from China lately? Fiio/Shanling/Cayin all claim nobody will ship the things anymore (thanks Samsung)
Don't mean to be a smart-ass, but if you do know someone who will ship batteries please let me know. Myself and plenty others looking for spare batteries will be ecstatic
|
|
solderdude
Administrator
measureutternutter
Posts: 4,881
|
DACs
Dec 5, 2017 7:30:15 GMT
Post by solderdude on Dec 5, 2017 7:30:15 GMT
Yes, obtaining Lithium batteries from China directly is a nono. I can't even order them from Farnell any more. But Conrad does still supply them. This can't help you because when I would send such a battery I must declare there is Lithium inside.
It is a bit weird though as almost all Chinese made products with (lithium) batteries inside are still shipped worldwide. Maybe a 'local' parts supplier can supply a similar battery ?
|
|
|
DACs
Mar 29, 2019 16:34:12 GMT
Post by Mr Trev on Mar 29, 2019 16:34:12 GMT
Hi Mr Trev! Heard you were going on the road to record DACs in their native environment (BestBuy), so thought you still wanted closed cans. But that was so 2016. Next time I'll notice the posting date, ignore it and post something inane anyways. ;-) A proper DAC? For $200 or under or $2,000 or over? $2000+ or go home! Seriously, under $200 is about right. Specifically, i'd like to spend less than I paid for my Vali2. I'm one of those people that believe the spending food chain goes headphones>amp>source Looking at the SMSL M100 right now - the part of me that pretends to be an industrial designer loves the look. It is "only" an ak4452 though (IIRC those are usually reserved for portable devices) and I've only found one review. That review is by that Zeos guy and considering I can't even sit through more than 2 min. of his videos, I don't know how much faith I'd put into his opinion. There's the SMSL Sanskrit 10 which is supposed to be decent (4490, lower format support), but the reviews I've read say that an external power supply is pretty much mandatory, and I don't know if that'll also hold true for the M100. I missed out on a great deal ($150) on an used ifi ione on CAM by ~20min. a month back. The reservation I have with that one however is that it seems the bluetooth (which I'll never use) is always active regardless of input. I don't really want a constant source of RF especially when I'm using tubes. The thing I do like about the ifi is they support all formats - imaginary or not
|
|
solderdude
Administrator
measureutternutter
Posts: 4,881
|
DACs
Mar 29, 2019 18:05:09 GMT
Post by solderdude on Mar 29, 2019 18:05:09 GMT
What formats does it need to play ?
|
|
|
DACs
Mar 29, 2019 20:50:26 GMT
Post by Mr Trev on Mar 29, 2019 20:50:26 GMT
Perhaps I was misleading when I referred to formats. Sample rates would have been a better term.
I do have some stuff in 24/192 and a few DSD albums. The M100 will max out at 32bit/768khz/DSD512, the Sanskrit10 "only" does 32bit/384khz/DSD256. I do realize that both are stupid overkill, but if you can get more features for the same price…
I suppose the more important thing would be the USB implementation. Both the SMSL and Topping d30 offer up XMOS chips, which I've gathered tend to be the most reliable. The biggest faults I've run into using both a Cayin N3 and my Shanling M2s as a DAC seem to be connection errors. The only way the Shanling can play without clicking/popping like dirty vinyl is if I upsample to DSD (never tried this with the N3 when I had it). Even using upsampling there's a pretty good chance it'll lock up during a listening session at least once.
|
|
|
DACs
Mar 29, 2019 23:39:15 GMT
Post by lobalwarming on Mar 29, 2019 23:39:15 GMT
Pretty sure, Mr. T likes the Adult Contemporary Format. Nothing as crass as the Top 40 Format. If you're not in rush, you might want to see how the new Schiit 'USB Solved Forever' usb hardware works - their own USB chip design. Supposed to be released this year. And supposedly better, more stable than SPDIF. Will be interesting to see what sort of Schiit show develops. For $99USD now, the Modi 3 would be my choice over the others in that price range. The stupid high sampling/pretend deep bit rates are marketing fakery, not features. None of those alleged 32bit units are better than a real 16-20 bit unit. 32bits can be marginally useful for mixing and editing - but 32bits is not a consumer requirement. Unless you're into one-time listening to jet takeoffs. 32bits = 192dB dynamic range. That's a feature? No, it's a safety violation. Read some Dan Lavry papers on ADC/DACs. Silly high sampling rates hurt more than help. "The optimal sample rate should be largely based on the required signal bandwidth. Audio industry salesman have been promoting faster than optimal rates. The promotion of such ideas is based on the fallacy that faster rates yield more accuracy and/or more detail. Whether motivated by profit or ignorance, the promoters, leading the industry in the wrong direction, are stating the opposite of what is true." - Dan Lavry Besides, in your chosen Adult Contemporary format, it's all low bitrate mp3s.
|
|