NuForce DDA-100 - Page 2

Truth be told, it has been resolved, at least within the scientific community. But I digress.
Measurements can tell you what information reaches your brain. They cannot tell you what your brain does with this information. What measurements tell us is that the device in question cannot possibly do what you attribute to it, leaving us to assume that this is a construct of your brain, based on something other than the actual sound you hear.

Such quality would be judged based on its level of fidelity. How true to the original source is how good or bad the sound reproducing equipment is. To be able to judge it, one would have to be familiar with the original sound.

Brainwave scanner can.

Except that the debate has been long resolved, both among scientists and knowlegable practitioners of the audio arts.

As you have stated the question, the properties that you are describing are its smooth, flat, and adequately extended frequency response, fair dynamic range and modest but sufficient freedom from nonlinear distortion. As mediocre as it measures, it is almost surprising that you don't hear any audible flaws that destroy or damage that stereo image. The ear is very tolerant.

I suspect that you think that the DDA-100 has unique abilities to create a very wide and deep stereo image (a slightly different question), and the cause for that is unknown due to lack of information. I can't read your mind. However its probable cause is the combination of knowing what you are listening to and remembering some sales pitch or hope that you had for the device. I'll refer you to "This Is Your Brain On Music".

Actually, a DAC is a kind of an amplifier. However, DACs are among the most highly perfected of all active components, especially considering that they operate without loop feedback.

There are very many such devices that are commonly used in audio production. A simple matrix can increase (or decrease) stereo separation.

The DQ10 was technically speaking, a mess. It was almost in the same league as Bose 901s as phase ambiguity generators.

Umm, as you perceive them. ;-)

Extreme familiarity with the original musical signal is one of those things that one gets plenty of during a good ABX test. One of the things that this does is eliminate or reduce the perception of a different sound due to lapses in memory.

Also fMRI scans.

http://en.wikipedia.org/wiki/Functional_magnetic_resonance_imaging

These are used to image the brain in real time as certain memories are recalled, etc.

Not remotely. They (and the fMRI Arny mentions) can tell us what parts of the brain are active in response to a stimulus, but we cannot (yet) use them to predict what our conscious response to that stimulus will be.

That does tell us what the brain does with given information. The degree of revealing can be debated. One of the ways to predict is to calculate the probability based on existing data gathered. If there is plenty of data on brainwave patterns per conditions the person is exposed to and their resulting reaction, then the prediction is feasible. More existing data there is, the better the chance of accurate prediction will be.

Something on brain scan and emotion: http://www.eurojournals.com/ejsr_44_4_14.pdf

This article seems to make my point better than yours.

Arnold's been pretty helpful in the past, at least to me. He's got decades of experience with this stuff. Although after reading The Audio Critic and reading many of the posters on here, I kinda assumed all EEs used digital and solid state gear over analog and tubes...until I discovered that there's still engineers out there who only use tube components in their systems!!! As one tube-using engineer told me when I asked him about that, "EE's are a diverse lot."
Edited by ThumbtackJack - 1/8/13 at 8:24pm

If what you want is a speaker that blurs every recording in an odd but characteristic way, then the DQ10 is for you!

However, don't call it High Fidelity unless you want to invent new meanings for the words high and fidelity!

Might I suggest a trip to the pawn shop and the purchase of a couple of cheap guitar amps? ;-)

The answer that brought most people to this forum is "The one with the highest fidelity".

That sounds to me like saying "Since I can't do this job perfectly, I'll intentionally mess it up very obviously and see if I can get by on people's appreciation of my way of messing things up". That's not really what great artists do.

I mean, do you want to listen to music, or do you want to listen to an intentionally flawed abstraction of it, when it is actually pretty easy to do better.

The findings of people who study this sort of thing is that people in general prefer better fidelity, lower distortion and smoother flatter response. That is surely what has happened to the reproduction of sound over my life time, and I'm not talking about just audiophiles.

Exactly. It's your property, your money, your time, your enjoyment.

However, I'm sitting here on a more-or-less public forum giving advice and offering opinions for the majority of audiophiles, not just a tiny minority with esoteric tastes.

As a rule they do.

Here in Detroit I live among what may be the largest concentration of automotive engineers and technicians in the world. Ever hear of the Woodward Dream Cruise? It is a week-long car parade dominated by classic cars. Do the owners of these cars use them for their daily drivers? Do they take them on pleasure trips other than those whose focus is driving classic cars? Not so much!

One of those cars is a friend's 1966 Cougar 428 in perfect (award winning) condition, with original everything and matching serial numbers. I've driven it and it is a beast to drive! After you tame the beast and get cruising on the freeway at 65 mph it feels like it is going at least 120 mph despite the fact that it has the best handling package and tires available in those days. Scary! Just to twist the knife there are many modern cars that you can use for daily drivers that will crucify it on the drag strip which is all that it was good for on the best day of its life.

There are a lot of intermediate steps that the sound goes through in a normal setup. The first being a DAC, then a line stage, preamp, and then a power amp. Of these are connected with interconnects that also influence the sound. Some interconnects restrict frequency response by their materials or terminators and can cause the bass and treble to be extended or muted. In the latter case, it causes the midrange to appear more prominent. All of these little changes when played with music can cause the music to sound quite different because the focus is placed on different aspects of the recording. This is what I attribute to AB cable tests. Having said that, this device (Nuforce DDA-100) bypasses many of these steps and as a consequence, sounds more natural. It reminds me of the uncanny valley. This is the instinctual recognition of reality vs generated. You know the difference between the photo of a face vs a really good computer generated face regardless of how it measures. In this case, the computer generated image can look too perfect or not contain enough asymmetry to look natural. That's the best way I can describe the differences between direct digital amplification and the traditional methods. The sound just seems correct in a way that most other methods don't. I have listened to a number of these devices and come away with similar impressions on each of them more or less. This particular device isn't bad although TACT and NAD produce better versions of this tech. Imaging comes from the integrity of the timing which I haven't heard discussed here yet. I have spent some time with the DDA-100 and it's overall presentation is very natural. I didn't feel that the sound stage was actually any better than my reference setup although it feels just about right. The clarity though is perhaps just perceptual but seems very real. Listening to recordings on this amp does seem to look deeper into the recording. Even when a recording sounds different to my memory, it makes a convincing argument that this presentation might be the "correct" one or more true to the original. I was impressed enough to add it to my list of gear to pick up when I get time.

Seems very old-tech. A modern system is usually based on an AVR with few interconnects and digital interconnects at that.

In fact reliable listening tests and bench testing show that nothing of the kind mentioned above ever actually happens in a typical home system, even with analog interconnects. Modern systems are largely interconnected with HDMI cables that are all digital. There cannot be any unintentional changes to sound quality in the digital domain with reasonable quality equipment.

If you believe in magic... ;-)

Unh huh! Whatever you say!

Arnold, you bring up an interesting topic regarding HDMI and the transmission of digital audio. I was of the opinion that a cheap HDMI cable would/should sound identical to a more expensive HDMI cable at least as it relates to audio. I was at a retailer who was trying to sell a customer on the idea of buying a $150 AudioQuest HDMI cable because the guy was interested in using his Oppo Blu-ray player as a respectable audio source and wanted to use his processor rather than investing in a dedicated 2 channel music only rig. I smirked to myself, and after the salesmen left the room, I quietly told the gentleman that he need not invest in a more expensive HDMI cable for his audio application. The data was transmitted as a digital data stream and it simply wouldn't make any different whatsoever. I left feeling good like I helped this man out. Some months later however, I discovered that the snake oil salesman of high end HDMI cables was actually correct. I attended a blind AB test where we compared 4 different HDMI cables. They were labled A through D and we simply kept notes on what (if any) differences we heard between the cables. Believing that there was no difference, I participated in what I believed would be a waste of time. To my surprise there was quite a difference between all of the cables. This leads me to believe that the method of transmission over HDMI is subject to audible differences in some manner. The differences between optical cables are well known but I had hoped that the industry was finally past "the cable making a difference". If anyone smarter than I cares to share why HDMI audio sounds different on different cables, I would be interested.

So far so good.

Sounds like the test wasn't blind enough. People throw the phrase "blind test" around but it has a very specific meaning.

The gold standard in audio testing is called the "Time synched, level matched, double blind test".

1) Time synched means that when sounds are compared they represent the identical same music down to the small fraction of a second. This is hard, particularly in a cable test.

2) Level matched means exactly that - that the music levels are matched very closely - within 0.1 dB if possible. This is often pretty easy in cable tests but needs to be verified.

3) Double Blind means that no person or other thing whose even mere presence could affect the test (such as being visible), knows or represents what is being used among the alternatives being tested, at any point in the test.

The last requirement is also very difficult in many cases.


The idea that a good digital link would cause unintended distortion, noise, or timbre changes is easy to show to be impossible, both practically and theoretically.

The so-called blind test was probably a spoof.
Edited by arnyk - 1/9/13 at 8:34am

A very simple test for any digital cable is to measure the ones and zeros that are pushed into the cable and measure the ones and zeros that come out the other end. Could it be that the ones and zeros are being transformed somehow into twos and threes - thus altering the sound?

This is not a test, it's, as you correctly called it, a comparison. When you compare two things, even if you do not know what they are, they often sound different. That's a form of expectation bias. You know they're two different things, and your brain takes that knowledge into account when deciding whether they sound different. It is unfortunate for audio comparisons that our brains work that way, but they do.

The right thing to do in the case you described would be to follow up that comparison with an actual test. Let's assume you determined that cable A sounded brighter than cable B. It would be simple therefore to listen to both of them (blind, of course) and decide which one sounded brighter. Do that 20 times, and see if you come up with the same cable as brighter at least 15 times. That would tell you that you really can hear a difference between those two cables.

If the cable doesn't have directional arrows on it, the ones could be coming out as negative ones.

All joking aside, HDMI cables do sound different just like Coax and SPD/IF. You don't have to have golden ears to hear it. Most HiFi shops will loan you a $150 AudioQuest Carbon HDMI cable for free and you can easily see for yourself if you haven't yet. I was just a little disappointed that after all these years we still don't have a digital audio interface that negates the cable as a source of variation. I thought HDMI would finally be it. As is the case with serially transmitted data, the time domain is the issue. For the time being the only good solution that I'm aware of is async USB which is what I use for my reference audio source. There is a replacement for HDMI that solves this problem elegantly called HDBaseT. For more information: http://www.hdbaset.org/technology/what_is_hdbaset I read about this a couple of years ago but it seems to be struggling against the momentum of HDMI. It looks like a great solution though.

No, they really don't. It's all in your imagination.
Nothing provokes the imagination like a pricetag!

Voodoo threads are the best...Tell me how your DAC has more impact than the room on achieving magical warmth so we can summon a few guys like Ethan Winter in here as well...

I wouldn't say it has more impact than the room... far from it... but a USB DAC has been a great addition for my PC music server to AVR compared to a sound card's SPDIF output I was using previously. More natural sound with less shrill/edge yet without sacrificing detail or soundstage depth/width.

With PC audio, some hardware and software combinations sound different to other combinations.

The USB DAC should have been either a neutral step or a step backward from the SP/DIF link.

Congrats! A USB DAC is a cheap way to make a big improvement in your sound overall depending on the model. Emotiva makes a great DAC called the XDA-2 that is also very inexpensive at $349. I prefer the sound of the XDA-1 better though as it has a fully discrete balanced class-a line stage that sounds great. The newer XDA-2 uses TI OPA2134 opamps and while it sounds good, lacks some of the air of the older model. Another intriguing DAC is the Schiit Modi which can be had for $99. It's USB powered so it's very easy to slot inline between the computer and your pre-amp or receiver. My only concern with that design would be the power supply from the PC. I've seen other designs like this that use rechargeable battery that is charged from the USB power. This is a cheap form of power conditioner and the results are good although it's $900 which is more than I would likely budget for that component.

I think I know why.

Yup, SPL meters are not reliable enough or accurate enough to match levels well enough to avoid introducing an audible level difference. The right way to do it is to measure the signal voltage across the speakers while playing a CD with test tones on it.

In theory. Indeed that's what I had thought too and used SPDIF from a sound card for a couple of years. However with the card's native ASIO bit-perfect interface, it sounded great providing I didn't do anything on the PC while music was playing. Even just moving the mouse pointer caused dropouts and pops in the playback. I had to use universal ASIO4ALL instead for stable playback although it didn't sound as good but at least I could keep using my computer for other tasks and it didn't need to be just a dedicated music server. Kernel streaming or WASAPI didn't work very well with the card and the various media players I tried either. Jplay sounded good and gave reliable bit-perfect playback, but wasn't as user-friendly as a normal media player so didn't get used that much even though it had a very good sound.

But things took a nice step forward when I finally tried some USB DACs. JRiver Media Centre 18 with its WASAPI event style is working very well between my PC and DAC. I am now preferring music playback better from my AVR even though I am feeding it an analog source than the digital SPDIF.