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In surveying the top-rated digital processors, I'm stunned that most don't use a true-ladder R2R DAC. Now, I'm aware that we don't *need* these for good sound. But for Robb Report prices, I would expect to get 'real' tech as much as possible (decoding without heavy processing).
Take the Soulution 560, a 1-bit DAC (w/ chipset costing $40), priced at $35,000. Unit has a digital volume control to boot. (No analog/digital, analog-only or optical attenuation, which from these, all great systems have).
The 560 sounds very good. It should -it has great parts and close attention to noise regulation, p/s, output stage, etc.
But this product is not alone, as (most other) world's best DACs are similar. Whether the Chord Dave, EMM DA2, Simaudio 780D, Berkeley Alpha Ref, DCS DACs, Gryphon Kalliope -all of these use 1 to 6 bit (cheap) D-to-A converters, with lots of band-aide processing.
Worse, it seems that even the *processing* is slow, as noted by Dave K. (here) last year. At least, when referring to DCS gear.
Current 'world's best' that use ladder-DACs: Trinity, CH Precision, Totaldac, MSB, Aries Cerat (Kassandra), CEC (DAO 3.0), Tidal (Camira) and Mola-Mola's DAC.
These (seem) to offer higher sound-quality over hybrid DACs.
Charlie Hansen once said it's like comparing a boxed-cake with one made from scratch. For this kind of cash, I would want scratch...
Edits: 02/21/17 02/21/17 02/21/17 02/21/17 02/21/17 02/21/17 02/21/17 02/22/17 02/22/17 03/09/17 03/09/17 04/15/17Follow Ups:
I didn't read every reply, but in your original post, you left out the PS Audio Directstream DACs, that use FPGAs and have made firmware updates available at no charge. That can't be cheap, especially when you consider the man hours it took to program.
I thought DCS had created their own proprietary Ring DAC,not using an off the shelf dac? And I just looked at the Chord website, they use FPGAs too. So, I think some of your info is not correct. How they implement those FPGAs is beyond my technical understanding. Chord says the Dave has a million lines of code.
I will say that with many companies using the same chips, it comes down to implementation, and the all important analog side. But as with most audio gear, the fancy case is the single most expensive individual part.
There are probably a *hundred* processors I left out. Units that use FPGAs are low-bit devices. In my piece, I listed world-beating processors that use ladders in architecture - 16 bit pure-resistors.
As already indicated (below), implementation has been the excuse for 20 years. It no longer works - something is happening with discrete-ladders. I'm just reporting the trend...
"But this product is not alone, as (most other) world's best DACs are similar. Whether the Chord Dave, EMM DA2, Simaudio 780D, Berkeley Alpha Ref, DCS DACs, Gryphon Kalliope -all of these use 1 to 6 bit (cheap) D-to-A converters, with lots of band-aide processing."
The DACs I commented on don't use "cheap" converters. That is all I am saying.
DCS may not be 'cheap'...
6-bit hybrids that have carefully-written algorithms can sound wonderful. It just seems strange that a (new) group of top-rated processors use an old-fashioned approach.
Beyond conversion, there's a lot of hype these days of 'Quad DSD'. But if I understand the speeds correctly, this is slow (256fs) compared what many were doing 12 years ago, when 768fs came out.
(2) points that question the technical advance of today's processors.
Interesting discussion, and I will admit that I own and listed to a vintage r-r ladder dac. I am also an EE, so have some understanding of the technologies involved.
It seems to be a discussion between what is more important, the sound or the spec. For me personally, I would not care what is in the box if it provides an improved listening experience. I trust my ears, and at the end of the day pleasing them is all that matters. I am not sure specs would provide any more than a starting point in my selection process.
The human is a strange and wonderful thing, and if anybody thinks they are all the same, then they might want to rethink that. Quality of hearing, sensory impressions, brain processing, all different and resulting in a different end result. A single spec is going to capture what is best for everyone?? Not likely. Specs also are based on effectively capturing a very complex entity, like a noise component, with a single measurement. At best a gross approximation, but most likely a basic starting point. Most useful to eliminate a potential component that falls above a particularly high threshold, but certainly not a selection criteria between close units.
I imagine the pure technologist sitting in front of their spec selected system convincing themselves - 'it sounds good, it sounds good, the specs say so', while their ears are violently disagreeing.
The proliferation of the low production cost units is a genuine problem. It makes it difficulty to even get a listen to a composite, high end, ear selected systems to serve as a baseline. I wonder if the technologists arguing here have ever heard one. If so, perhaps they could provide the details of that system and the 'high spec' system that sounds noticeably better. That would probably help provide perspective. It is simple to hear a high end, high spec system, as stereo stores have them to listen to. The others are rare as hens teeth, as many of the components to put them together are either vintage and very hard to find, or current and very expensive ($ 31K for a dac).
Of course, at the end of the day it is all about what sounds best to you.
regards -- Roger
"Now, I'm aware that we don't *need* these for good sound. But for Robb Report prices, I would expect to get 'real' tech as much as possible (decoding without heavy processing)."
I think expensive processors with cheap chips stemmed from the belief, from the designer perspective, that precise discrete D/A circuits don't offer sonic value added relative to inexpensive off-the-shelf chips. I've heard good and bad examples of both..... But I personally like the "cheap", dated (late 1980s technology!) DAC inside the Philips CDC-935 CD changer as much as any from-the-ground-up designed DAC inside products that cost five figures. Save for the Wadia 9. (As long as the analog circuitry around that cheap DAC is upgraded to bring out its sonic capabilities. Don Allen's [RIP] mods achieved that to the highest degree.) I mean, a sound that makes me content giving my vinyl rigs a rest. And totally disinterested in any server-based or high-resolution digital audio playback.
You are leaving out the Audio-GD Master 7 dac which uses 8 each 1704 chips $2500. Best dac I have ever heard
But is it the chicken or the egg? There is no reason to believe that the chip is solely responsible and not the package.
I agree but I definitely here a difference between r2r chips and delta/sigma chips
Except, how can you be certain what are the technical cause(s) for what you feel that you subjectively perceive? Even should you be able to reliably detect between DAC boxes employing a full resolution converter and those employing sigma-delta converters, that may be do to some correlated secondary system implementation factor, and not due to the converter technology itself. I'm not declaring that you cannot reliably tell a difference, I'm questioning how you can reliable assigned that difference to the converter type. This reminds me some of declarations by some that they can hear the difference between bipolar and MOSFET power amplifier output stage devices.
How can you be certain it is not the chip that is determining the differences I hear? I have owned 4 ladder dacs and 2 delta/sigma dacs and have heard many more dacs at shows and at my audio club. The differences I hear are always there. One area that I believe causes some of the difference besides the chip is the digital filters that are used used in ds dacs vs no digital filter in ladder dacs.
Actually a good point.
But there was never much debate of bi-polar vs. MOSFET. If there was, it was brief and died-off a long time ago.
The movement (back) to ladder-DACs has been going on for years - and still growing. I suggest this is due to noise dropping, overall, in the processor. Differences can now be heard.
In my piece, I said the 1-bit processor sounded very good - I have heard it. But IMO, the ladder-units sounded more natural inc. longer instrumental decays.
I also questioned the value of extremely-expensive units that use cheap chips and (one) adding a digital volume control.
UPDATE: I found another pure-resistor 'best' -CEC DAO 3.0.
Yes, it was discovered that so-called MOSFET mist was often due to the driver stage not having a low enough output impedance to minimize the distortion produced by the MOSFET's non-linear gate capacitance. In other words, was due to an device type specific implementation issue, not to the device type itself. This is akin to DACs, which are comprised of far more sophisticated technologies than is an power amp. Many factors are in play including, clock jitter, digital interpolation filter, I/V circuit, analog output filter, analog output amplifier and supply regulation and isolation. Differences in sound can be due to any of those factors and not simply to the converter type.
It seems to me that some audiophiles are too anxious to claim perfect knowledge of the technical causes behind some subjective listening experience when they don't actually possess such knowledge. I think it interesting that some other audiophiles also claim perfect knowledge of the technology with respect to the listening experience, but instead to argue that there are, in fact, no subjective differences to be heard. My view is that both are wrong.
I never know that about MOSFET amps. Thanks for the info!
But if there's a *pattern* of ladder-DACs sounding similar, then (better) than delta/sigmas, we have something. As noted by users here and the resurgence of resistor-types, in general.
But you are so quick to ignore this. Then, fiercely defending cheap chips. Not too many would do that, as we're seeing...
At the risk of sounding like an objectivist, which I'm not, perceived patterns could be real or imagined. Sometimes, we do recognize a real pattern but misidentify the cause, as I had
pointed out in the MOSFET mist example earlier. One of the facts you learn in statistics-101 is that correlation does not automatically prove cause-and-effect. For example, just because a rooster crows just before sunrise doesn't indicate that the rooster crowing is making the sun rise. We must be careful not to fall for such logical fallacies.
...and you are so quick to mischaracterize what someone else has written. I have not fiercely defended sigma-delta. I have accurately and fairly commented on it's objective advantages as well as disadvantages. Furthermore, I've not made one comment about the subjective sound quality of any of the converter types. You, on the other hand, have done all those things in favor of R-2R. So...
So we'll ignore the comments (here) and the industry's return to ladder-DACs as stat-theory. Good job.
And (below) you said 'don't be hard on engineers'. Defending the delta/sigma programmers....
DACs are probably the most complex consumer stereo component. As such, it is exceedingly difficult to assign technical cause to subjective listening result. On top of that, digital signal processing is a non-intuitive technology. Concepts like sampling itself, dither, and noise-shaping are just a few which are commonly misunderstood. What intuitively makes sense with analog often is incorect with respect to digital. For example, analog processing typically exhibits increasing distortion with increasing level, while digital processing typically exhibits decreasing distortion with increaseing level. For another, adding noise (dither) reduces digital distortion. In addition, audiophiles often believe that simpler is necessarily better, so, more digital processing is necessarily worse than less digital processing. Except, that isn't necessarily, or even typically, true with digital.
There's little that seems 'natural' about a digitally sampled system in the first place. More digital processing can be better than less, and often is, but it depends on the implementation details. R-2R (only one kind of multibit), or some other multibit converter technology isn't inherently superior to 1-bit sigma-delta, it depends on the details. 1-bit sigma-delta converters inherently exhibit perfect linearity, but also exhibit very high quantization noise. Full resolution multibit converters are the opposite, they exhibit low quantization noise but less than perfect linearity. Multibit sigma-delta is a hybrid of the two, intended to bring together the benefits of each technology while minimizing their drawbacks.
It would be convienent if we could determine a laundry list of technologies which would ensure our obtaining subjectively satisfying sound from a given prospective component, but I know of no such list as yet.
I agree with your post. Many of the assumptions made about computer audio are just copy throughs from data processing technology and not related to sound quality, electronics or acoustics considerations.
Thanks for saying that delta/sigmas have very high quantization noise. As you know, quantization is a cornerstone of digital audio.
Look at the specs -the Burr-Brown 1704 measured much better than delta/sigmas. But delta/sigmas invaded high-end audio. Partially due to availability. But then engineers *ignoring the specs* and marching forward with cheaper chips.
Why start off on the wrong foot ?
Delta/sigma replaced ladder chips because of cost. R2R chips became very expensive and Delta/Sigma are very cheap
But also look at the distortion specs. for PCM1704, especially at lower signal levels, such -60dB. The distortion is greater than it is for a modern sigma-delta converter.
As far as the engineers, don't be too hard on them. They get driven by market pressure too. Those that pay the bills get to call the shots - customers. The market wanted lower cost converters still having good distortion specs. Noise-shaped sigma-delta modulation (SDM) converters typically exhibit much lower audio band distortion than do full resolution multibit converters.
Full resolution multibit can also made to have low distortion, but typically requires time consuming costly trimming, possible by hand, depending on the design target. In addition, the greater the number of bits, the more difficult is achieving a commensurate reduction in distortion. Therefore, 24-bit sample size further accelerated the issue. SDM enabled low audio distortion conversion at a low chip cost despite it's other evident drawbacks. I believe that was the primary reason for the market takeover by SDM converters. Today, the market is dominated by hybrid multibit sigma-delta converters.
In high-end products, I don't see any 'cheaper' processors.
Delta/sigmas have much higher (measured) noise and distortion and that's final. Lynn Olsen's reports on PFO show this...
Believe what you will, but that's factually wrong. An PCM1794A, or an AD1955, or the Sabre chips, etc. produces lower in-band noise and distortion, especially at low signal levels, than does any legacy mass production full resolution multbit converter, including the PCM1704. Read the various datasheets for yourself, unless you believe they all lie. The SDM converters do have greater out-of-band noise - meaning, measurable yet inaudible ultrasonic noise. That said, the multibit converters do have their objective advantages. Subjective sound assessments, of course, vary.
BTW, Because some high-end DAC box is costly usually has little relationship to how costly is the DAC chip being utilized.
If you believe cheap chips (which discard data) are superior than pure-resistors, that's your business.
Data sheets mean nothing -they cover up and highlight what they want. It's independent study that counts.
"Mountains and Fog" -2 part article at PFO and "R2R/multibit vs. Delta-Sigma" at Head-Fi are good places to start.
As noise is (slowly) dropping in digital processors, we're hearing differences in DAC design. Could we have done this in the 1980s and 90s ? I doubt it...
If you believe so robustly on what the web says about dac chips, then there is not much to be said.
It is not chip technology but package implemetation, including the digital filter, I/V, analog stages, and digital input conditioning that most affect SQ.
Well, then, there's no sense in my trying any further to open an closed mind.
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