einai

It is indeed possible that there is some difference in the USB drivers in the Mac, or in the way I have it configured. I have been able to get better sound over USB using a Resonessence Concero, which actually contains a cheaper Sabre chip than the DAC2. That would appear to indicate that my problems were indeed related to some sort of USB issue.

In my case there was a pronounced difference on all sources. But since we are looking at different OS's, drivers, players, hard to draw any conclusions.

I may have misunderstood what you are saying, but I think it should have sounded worse when it slipped into USB1.0 on all sources. Do you mean you don't hear a difference between the same source playing in 1.0 and 2.0 (leaving >96kHz, buffer misconfigurations out of consideration)?

In my case--and let me emphasize that I am only reporting what I observed in my setup (MacMini/Amarra [current releases from Jan-May, 2013]--all components continued to show that it was still in USB2.0; however, if I cycled the settings as mentioned in my first post 2-1-2, the sound was noticeable better. I believe I first became aware of the issue wrt 192kHz files, but then came to realize that this was always the case. So, to be accurate, I should say that after a track change, the sound in USB 2.0 deteriorated in a way that was comparable to the way it sounded when running in 1.0. It still always sounded better than the DAC1. Again, I cannot rule out that the problem was somewhere on the Mac/Amarra side. It was hard to compare the sounds, because of course I had to do the reset between comparisons. I would be curious to know whether others observed this, and also whether they have not. Perhaps there is something I am doing wrong elsewhere, since the audio interface settings in Amarra, Audio MIDI etc. are quite intricate and poorly documented.

I replaced a DAC1 with a DAC2, but sold the DAC2 after a couple of months. I found that the USB 2.0 only worked correctly after I cycled through UBS2->USB1->USB2 (owners will understand what I mean). That is: immediately after a reset of the USB connection, it sounded swell=noticeably better than DAC1, but it seemed to drop down to USB1 quality whenever there was a track change. (Still showed as USB 2.0 in all system panels, Amarra preferences etc.). This was using Amarra on a Mac. I'm not ruling out the problem was on the software side, but having gone through the whole "Ultralock" story on the DAC1, and after spending forever trying to isolate the problem, I just decided to move on.

As I indicated in the post immediately preceding yours, it blows the DAC1 HDR (which I had before the DAC2) away. The differences are across the board: audibly lower noise, greater high resolution, and lows as well (eg string bass). A large part of this is clearly the USB interface. When you toggle between USB 2.0 and 1, you hear a big difference right there. The lower noise is probably attributable to the DAC itself, but what do I know.

Prolly I should apologize for having dragged things off topic. In fact I love the Dac2, which I use with amarra, macmini, perreaux 1150b and KEF 105s. Haven't tried the headphone amp. One thing that I noticed immediately: live recordings that I subconsciously avoided in the past no longer sound muddy, but have a soundstage and even sound better than some studio recordings. And this is program material from the 70s-90s. So I am clearly getting a ton of treble resolution that just was not there on the Dac1. Older digital recordings eg DG Archiv no longer sound quite so shrill. Tho there is no saving those dogs, I fear.

Thanks for that. Indeed, this is a limitation for anyone who wants to switch between sources.

Yeah, I saw that, couldn't quite figure out what it was for, but presumably it controls the on-chip volume attenuator plus source? If they are really being honest about this being "the digital processing core of the INVICTA", it looks like an arb. But of course I've never heard it.

Actually the Concero does have SPDIF. Just no remote and no preamp. Just the thing for my father-in-law.

I did download some DSD files, but for the moment the tradeoff of having to deal with them (I use Amarra, which at present doesn't support them) coupled with the lack of source materials has it on hold. In my dreams, I would get an Resonessence Invicta (company belongs to the designer of the Sabre DAC), but I would certainly suggest that anyone take a look at this, Concero | Resonessence If I could get that with SPDIF and a remote, I would happily trade the DSD functionality.

Replaced my DAC1 HDR with a DAC2 principally because of the async USB. Don't know how much it is the async and how much the Sabre chip, but it is a substantial improvement on the DAC1. I haven't tried out the DSD and am unlikely to.

Hi, I recently replaced by DAC1 HDR with the DAC2. Huge difference. The externals are similar, but it's a much better DAC, completely different inside. I don't care about DSD because there isn't every going to be much of it. What is overwhelmingly important is the async USB. Took me two years to figure out there was something wrong with the USB implementation.

The situation is no different than with the evolution of CPUs. The DAC, strictly speaking, is the chip itself. Everything else merely feeds the DAC and amplifies its output. There are technical subtleties here, but they are not in fact DAC-design issues at all. Regarding the claim that "the actual physical layout of the Dac itself is of EXTREME importance". Yes--you can implement it badly. The "actual physical layout" of the the actual DAC, however, dwarfs that. And what dwarfs that even further is the underlying mathematics. Lastly, you don't know Martin Mallinsson's biography from watching that video. You are confusing the work of physicists and mathematicians with that of technicians, fundamental engineering with consumer product implementations.

Look, there's no point squabbling about this--the substantive point is that the ESS Sabre is 80% of both of these DACs, and if you knew anything about Mallinsson, you would realise that he is an extraordinarily talented physicist and engineer. The physics, mathematics and engineering that went into that chip put any of the details of assembling a DAC unit, which couples that chip to some interfaces and possibly a preamp, in the shade. The latter is chickenfeed compared to the thought that went into this design, which is why ESS bought him out. When we talk about the Weiss, the Benchmark, and the Resonessence, we are just talking about implementations of the Sabre DAC. This is not a trivial business either, but it's not the real deal.