You don't seem to know much about how USB audio actually works, just a bunch of anecdotes that don't have any meaning.
Mass Drop Grace Sdac. I recommend this as it was shown to properly handle inter-sample over range cases by our local DAC expert Bob Smith at our AES meeting. When music files have signal samples that approach or reach the max and min values for the format, a DAC with an improperly designed interpolation filter can produce huge distortion when it goes out of range on these "intersample overs". Many DAC's on the market apparently don't handle this case well. The Grace Sdac is an inexpensive one that was tested and found to perform properly. You can check out the meeting recording and slides here: AES PNW Meeting Report - Issues in Digital Production That Remain a Problem
Don’t be so sure. USB audio has come a long way, but the starting point was heavily flawed, and it is still getting better, implementations in the field vary greatly (as we use the word greatly to describe small but signiifcant sonic differences).
I do hope Intel can succeed in their quest to have ThunderBolt sucked up USB. USB as a subset of ThunderBolt and the USB-C* connector are a start.
*(the only difference between Thnderbolt and USB connection now the quality of the cable, USB getting away with an inferiour one (one could use a ThunderBlt cable for USB, but not visa-versa).
dave
John Siau, the designer of Benchmark DAC-3 talks about intersample overs too. He says they cause little bursts of high frequency noise that 'can' be audible. No exaggeration about 'huge distortion.' Scott Wucer talked about it too, IIRC he said the worst case would be at fs/4 ~11Mhz, where most music does not have much energy (also meaning huge distortion less likely). Through most of the history of CD audio and until the later part of the loudness wars, mastering engineers knew to keep levels low enough so intersample over distortion would not be problematic. What happened though was that customers (producers, bands, record companies) kept wanting louder and louder CDs. Slowly mastering engineers started experimenting with pushing up the level closer to digital zero while listening to for objectionable distortion. Some didn't find the distortion objectionable at all. Some recording engineers found it to be inaudible. None the less, it could be audible with some types of recordings although those aren't typically the ones most involved in loudness war competition. Whatever one thinks about the problem, one thing has become clear to me: It is hardly the worst sounding shortcoming of most cheap dacs, IMHO.
The JL Sounds dac I recommended is still probably the best sounding of the bunch. If intersample overs are a concern, all one need do would be to turn down the digital volume control on the computer about 4dB below maximum and that would eliminate the distortion. That is exactly what dacs that have intersample over protection do, they turn down the volume a little before it goes into the dac chip.
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So then, what is Thunderbolt? Maybe you can explain how it is different from USB. I maintain you don't know the first thing about Thunderbolt, USB, or the USB Audio Class specifications other than what you have read from Wired type articles and from high-end audio people who speak a lot of BS. Perhaps you can explain why UAC 2.0 asynchronous endpoints are not sufficient.
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That is a completely seperate thing. A FR or a multiWay can be TL loaded. A TL small enuff to fit on a desky=top won’t go all that low. A FR also means you are buying 1 driver per box, or for the same money 2 drivers & an XO. Quality vrs quantity.
The type of box loading is different thing than 1 or 2 drivers (+XO) for the box.
Her eis a set of good Desktop TLs. Woden Design 3" Box Designs, BabyLabs & more
Many others (not TLs) too. Including miniOnkens (uFonken, uMar-Ken, others), Martello, XRK has a few.
These are the 1st gen uFonken.
dave
Ok now you've got me going down the TL rabbit hole lol. Yes, I think with nearfield one driver per box is probably ideal. I'm going to need a small but potent sub to go under the desk as well. I also think the front ported speaker boxes would probably work better since I have a hutch over the desk, and I don't want the thing to sound like an echo chamber.
I think you should look what this guy is doing with CM6631A, you will be surprised:
https://www.diyaudio.com/forums/dig...m6631-usb-audio-interface-69.html#post5453793
and
CM6631 usb audio interface .... any good?
I think you should look what this guy is doing with CM6631A, you will be surprised:
I’m sure Mark squeezed as much as he could out of the chip. It is what is in my Gungnir (Gen5 USB, as in his 4th iteration of using the chip for USB) and i have no complaints (except that i’d like to be able to afford one of the latest Yiggys).
dave
In 2018 Audio GD R2R-11 was a hot product on the head-fi.org forum. Thousands messages, most posters agreed to the quality of DAC section and a headphone amplifier. The same on the smaller South African website avforums.co.za. The only criticism was regarding clicking and playing DSD content. DSD playback is bad, I agree and there is a workaround. I do on the fly conversion to the PCM 176.4kHz in Foobar. Audio GD is using a similar technology as Soekris, you should be familar as developer is present on the forum.
R2R-11 is not a hot product anymore, as fans are aiming higher. There is a more expensive model R1 with fully balanced DAC modules (four in total). It sounds even better and audioheads found that it sounds really fantastic on their expensive headphones when paired with NFB-1 amp. In respone a new combo was released, it is essentially R1 plus NFB-1 amp. This new model is R28, it costs 3 times more than R2R-11 and audioheads have jumped in. It is why I got mine second-hand.
There is more stuff in the A-GD offer, with galvanic isolation and other high-end features, prices are around $3K. That is a short story about Audio GD and successful DA-8 DAC modules. The previous version was not very good, I gather from a feedback.
As for measurements on the ASR, my engineering experience is such that I can tell you for sure that Amir was measuring not a DAC, but ground loops in his gear. It applies to both R2R-11 and TotalDAC (another botchered test), the same noise pattern is present in both tests. When you look at a TotalDAC measurements, there is a photo of a BK Precision AC power source generator. This equipment was used to convert US power to the 240V European standard. I entered discussion with Amir arguing that it should be only one (if any) trace of 50Hz or 60Hz on the FFT graph. For the one Amir blaimed a DUT, but the other one clearly indicate ground loops present exclusively in his measurement equipment. Amir response shows that he was absolutely ignorant about ground loops and subsequently I was banned from ASR for disrespect. A discussion with Amir continued later on the avforums.co.za, you can google on that, Amir didn't learn anything.
There are other faults in his test, I didn't enter to such details, others did. I only want to point out that R2R due to the complex structure of the ladder requires at least 100 hours of conditioning, after such period it needs half an hour of warming up to achieve optimal performance. Amir didn't do it, he didn't say he did.
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