There's no such thing as digital: A conversation with Charles Hansen, Gordon Rankin, and Steve Silberman

During a conversation with AudioQuest's Steve Silberman, Steve brought up the notion that "there's no such thing as digital" which I found thought provoking. I suggested to Steve that we have an email conversation about this very topic and Steve suggested adding Charlie Hansen of Ayre Acoustics and Gordon Rankin of Wavelength Audio into the mix. So that's what we did. The opening question:

It's common for people to envision and represent a digital signal as a series of 1s and 0s. As such, there's really no room for error, at least according to this binary theory. Is a digital signal simply a series of 1s and 0s?

Charlie Hansen: Unfortunately not. The "1"s and "0"s are just abstractions that are easy to think about. But in the real world, something real needs to represent those two abstract states. In modern digital electronics, we have almost universally chosen a voltage above a specific level (that varies from one "family" of electronic parts to another) to represent a "1" and a voltage below a different specific level (that again can vary) to represent a "0".

In the real world, those two voltages are not the same, so there is a "grey" zone between the "black" of the "0" and the "white" of the "1". Also, it takes time for the signal to change levels, and the time required to do so can depend on dozens (or even thousands) of other external factors.

"All of the problems with digital are analog problems."

All of this can be boiled down to a simple phrase. "All of the problems with digital are analog problems."

This is the primary reason that digital audio has taken so many decades to come close to the sound of analog. When digital audio was introduced, none of the top analog designers of the day knew anything about it. So it was all designed by digital engineers. Digital engineers have gone through years of training where these problems were never mentioned. And as time went on engineering schools put less and less emphasis on analog circuit design.

There is an entire generation of designers that lacked even a basic understanding of analog electronics. And without a thorough knowledge of analog electronics, the problems of digital can never be addressed, let alone the problems of analog electronics, which will always be necessary. Currently good analog engineers are in high demand because there aren't many of them left! So a lot of schools are adding analog electronics back into their curricula.

We live in an analog world, and all signals start as analog signals and must be returned to analog for audio playback. Modern video displays are about as close to pure digital as we've gotten so far, and even there the fact that there are still analog problems in digital electronics is what separates the good from the great.

Gordon Rankin: Many people talk about digital data and bit perfect in a singular sense. But in reality things are very different. The testing involved with doing a real bit test is larger than anyone really would want to take on. Just using the obvious methods of the indication of a HDCD marker or recording a signal and taking the analog equivalent and subtracting them to see a difference only covers a really finite amount of what a true bit perfect test is. How about we take a song output over an S/PDIF transmitter to an S/PDIF receiver, record that and compare the two (original file and the data received)? Why stop at one song, but maybe 10, 20 songs, 8 hours worth.

But aside from the data being true, there is so much more. How much energy is wasted delivering the data seems to have an effect on sound. As with increased energy usage the amount of EMI/RFI radiation also increases. This might be a reason why applications sound different. If we look at the "top" command in the Terminal application on OS X we see a programs usage and percent time and all the processes associated with that program. In practice the applications with the least required processing time also sounds the best. This may have an indication of why file types sound different. If you unpack a lossless file on the fly the processing time increases measurably and that tends to decrease the sound quality.

"People talk about USB and Firewire jitter being an issue and it can cause data errors. But really this is not the audio related jitter error that is most important."

Also how do we get the data there is a whole other topic to be taken on. We are basically packing audio data up into finite packets of bytes and then sending them over some serial link, one bit at a time and then rebuilding this data into a format for which the DAC chip will accept. People talk about USB and Firewire jitter being an issue and it can cause data errors. But really this is not the audio related jitter error that is most important. That has to do with the way the DAC receiver formats output data to the DAC chip and the associated audio master clocks and audio serial format (I2S, left justified, right justified, DSD, etc...). Then there is flow control over the network from the computer to the DAC. I don't know if any of you are looking at this... I have and it's not a pretty sight. So just doing this on average is not a good thing and there is an appreciable difference in sonics depending on the way you handle this.

Anyone who feels it's only "1" and "0" is missing a ton more variables that need to be addressed.

CH: The complete system used for CD's was developed before CD-ROMs were used for computers. It was only later when people started to realize that a CD could hold MUCH more data than any other transportable medium of the time (eg, 650 MB for a CD-ROM versus 1.2 MB for a 3-1/2" high-density floppy disk) that they adapted the CD for use with computers.

There are several very clever back-up and redundancy systems built into the audio CD format so that it is fairly rare for there to be an actual error in the bits (eg, a "1" will be misinterpreted as a "0" or the converse). However, the error rate is still too high to be used for computer files, so another layer of error correction is added to a CD-ROM in addition to all of the error correction systems found in a CD.

NB:Copying an audio CD to a CD-ROM will NOT use this extra layer of error correction, so there is no reason to copy all of your audio CD's to CD-ROM's. However if you rip your CD's to your hard drive using a system such as AccurateRip (employed in several ripping programs, such as dBpoweramp, see for additional information), the checksum from your disc rip is compared to hundreds (or even thousands) of other submissions from other users and you can be confident that the audio data on your hard drive is a bit-perfect copy of the original master used for the CD. At this point, the data correction built into your hard drive will take over and protect your audio albums from any possible corruption -- at least until your hard drive fails. This is inevitable -- ALL hard drives will fail sooner or later, so be sure to BACK UP your music files!)

Getting back to the "grey zone" that exists between a "0" and "1" in ANY digital system, it is rare that the errors are so large that there will be actual corruption of the data. It can happen -- most people have seen a digital display connected with a cable that is either poor quality and/or too long for its intended purpose. Often this will show up as green "streaks" in the picture. It can also happen with audio. If the cable connecting the DAC to the computer is either poor quality and/or too long for the system in use, there may be randomly audible "ticks" or "pops" during playback.

"But since digital audio is a streaming system, the timing of the bits is critical. If the bit changes to the correct state but at the wrong time, this is equivalent to changing to the wrong level at the correct time."

However, it is important that ALL audio systems will suffer ill effects from this "grey zone" even if there are no obvious audible problems. This is because the error is not large enough to change the state of any particular bit. But since digital audio is a streaming system, the timing of the bits is critical. If the bit changes to the correct state but at the wrong time, this is equivalent to changing to the wrong level at the correct time. These timing errors are known as "jitter".

[GR: Audio streaming protocols are typically not error correcting. Standard Asynchronous and Adaptive protocols only cover flow control, not error control. The analog behavior at the receiver side of any streaming interface can have a lot of effect on the quality of the received data which will directly reflect the quality of the audio.]

It is rather unfortunate that jitter was the first timing error to be described in the context of digital audio, as it has become by far the most common way to refer to timing errors. But it turns out that far more important than the absolute amount of timing error is the spectral distribution of the error (ie, how much error is there at high frequencies versus low frequencies), and whether that timing error is correlated with the audio data (music signal) or if it is just random variations.

More sophisticated test equipment is required to test for this, and you will see this referred to as "phase noise". The phase noise is measured at a frequency that is offset from the desired carrier frequency. A graph of the phase noise versus the offset frequency provides us with information regarding the spectral distribution of the jitter, and is the best tool to date for measuring timing errors (ie, "jitter") in audio equipment, as it is the most sensitive tool and has the highest correlation with audible differences.

AS: Since there's no such thing as 1s and 0s in digital transmission, what is being sent over our USB/Firewire/Ethernet cables when we play back music files?

CH: An ANALOG signal!

Steve Silberman: I think this is where things get misconstrued. The signals we think of abstractly as “digital” are in fact high-speed analog square waves, susceptible to all of the same damage and distortions as any other analog signal.

AS: So when we talk about digital music playback, we're talking about a continuous system as opposed to a discrete system. In effect, once we hit play, our data is transformed from a discrete state into a continuous state which is, for all intents and purposes, governed by the laws of the analog world. And one of the most critical aspects of this continuous music playback system is time/timing errors/jitter.

GR: One thing that people have to realize is that these type of interfaces all work differently. I think that cable companies had to overcome when computer audio hit the market was... this stuff is all different than an S/PDIF cable. Which was really the only digital cable most of these companies had any experience with.

These interfaces all come with protocols which make not only the electrical aspect more demanding, but also details that are not apparent in S/PDIF cables.

"The turnaround time is the amount of time the cable settles to allow the other end to start transmitting without the signal being corrupted."

I would add one really key component to the list [time/timing errors/jitter]—what is called "turnaround". All of these protocols are asked for some kind of response. The turnaround time is the amount of time the cable settles to allow the other end to start transmitting without the signal being corrupted. It has to do with capacitance, length and impedance. For example some companies were making 50 foot USB cables stating they kept the capacitance low enough to make this work. I asked if they tested it on any asynchronous USB DACS and the answer was no. Well the problem was the host was never seeing the feedback pipe which made the DAC under or over run. The turnaround on these cables was sooooo long that when the DAC was asked to send the feedback pipe data that it was all corrupted when it reached the host.

AS: What about digital filters? How does a digital filter differ from an analog filter and doesn't this difference point to a digital "state" within the playback chain?

CH: As we have seen, "digital" itself is a very abstract concept. In the real world, there is some real physical quantity that represents "digital". For example, when the voltage exceeds such-and-such a threshold we define that as representing a "1".

But there is one place where our abstract concept (of the human brain) becomes (in a very strange way) tangible. And that is inside the electronic brain of a digital computer. Now the term "digital computer" can encompass a wide variety of things, from a simple gate that compares two signals to a sophisticated modern PC with billions of transistors operating at thousands of megaHertz.

When this electronic brain receives signals that represent 0's and 1's, it will carry out a very specific set of operations on those numbers as if they were really and truly digital. A good example of this is when one sees the image frequencies created by a digital sampling system. In the textbooks, these image frequencies repeat at multiples of the sampling frequency and go on forever -- to infinity and beyond!

This also happens inside the electronic "brain" that performs the computations, but as soon as the signal comes out into the real world, it has to conform to the real physical laws. For the image frequencies to continue forever, the impulses from the DAC chip would have to be infinitely narrow. Of course something infinitely narrow wouldn't exist. So a mathematician named Paul Dirac invented an abstraction called the "Dirac delta", where delta refers to a change. So it is an imaginary pulse that is infinitely narrow, but to have any energy it would also have to be infinitely tall. Of course such a thing cannot exist in the real world, but it exists in the equations created by digital mathematicians and calculated by the digital "brains" inside digital equipment.

As soon as that imaginary pulse comes out into the real world, the digital "brain" gives instructions to real switches that cannot change states with infinite speed. So they are stretched out to have a finite time, and this causes changes in the actual frequency response compared to the theoretical response.

But inside the "digital brain" of the equipment (and the brain of the digital engineer) is the only place that the signals are truly digital.

"But inside the "digital brain" of the equipment (and the brain of the digital engineer) is the only place that the signals are truly digital."

GR: When people ask me about digital filters I always have to remind them that most of the math we use here for digital filters was derived by the work of LaPlace and Fourier in the early 1800's. Remember to them, there was no computer. This math involves two tables, one of samples the other coefficients which make up the filters. A table with the audio data is multiplied by a table with the filter coefficients and accumulated to form a new output sample. LaPlace and Fourier therefore worked with infinite math models. Not 32 bit floating point, 24, 32, 64 fixed point math models. They assumed you had all the time in the world to do these computations, instead of in between two samples.

"...the larger you make the coefficient and the sample work into a larger model say 64, 72 bits or higher and don't over or under-run the math model, then the better it's going to sound."

This is why filters all sound different. A coefficient is less than 1, so it's a fraction. If you look at this as we do, then all the math here is fixed point, meaning there are no fractions. We multiply the coefficient by some factor, usually a multiple of 2, because we have to divide that out in the end to make the output sample correct. In fixed math it's faster and easier to divide by rotating the data right one spot (divide by 2) or 2 spots (divide by 4). But as Charlie has found out and something we were taught at school, the larger you make the coefficient and the sample work into a larger model say 64, 72 bits or higher and don't over or under-run the math model, then the better it's going to sound. Most commercial chips used 24 bit models for their math to make the chips cheaper. Some companies have really come around [and are building DAC chips with higher precision math models] and that is why the chips sound better and more realistic.

AS: To be continued...

jim tavegia's picture

If the gentlemen are saying that the 1's and 0's are really voltage representations of the digital data, then would the slew-rate of "that" amp producing them and its speed become an important factor in properly producing the data stream? 

Also it has been made clear over the years that many inexpensive DACs have become low jitter machines and measure well and produce great square waves, but it is their analog stages that hold back their overall sonic qualities, so the analog part of this conversation does make sense. 

Very interesting column. I am still kind of surprised that now with DSD streaming beginning to gain steam that Firewire was not pushed harder by the high end audio industry as their port.  It seems like the industry needed to work awful hard to make USB work at all. It seems like USB should have been left to keyboards, printers, external HD's,  and mice. 

coreaudiotechnology's picture

Really great article! I have been looking for a source to site in some of my articles about why power supplies are so important in digital audio.

Noise from the power supply introduces voltages that create amplitude distortion in the square wave, this introduces harmonic content that doesn't exist into the audio signal.

I look forward to reading the continuation of this article!

rtrt's picture

not convinced this part is true...

'At this point, the data correction built into your hard drive will take over and protect your audio albums from any possible corruption -- at least until your hard drive fails'

As far as i know bits within audio (or any other) files can be flipped and at least with media files the error won't be detected by Windows or MacOS. Less sure about Linux.

The error rate for a hdd is I think another representation of this. Those error rate numbers are pretty small, but disc capacities are very big and so the likelihood of a given file on a disc being affected is larger than we might think - sorry no maths - time for bed!

tnargs's picture

I hope nobody is silly enough to believe any of this nonsense. It would really be damaging to the credibility of audio as a hobby if this sort of magic-disguised-as-technology took hold. 


It is as if all one has to do is say six true things as a sandwich to hide a silly untruth or *exaggeration*, and hey presto, the $10,000 DAC clock upgrade you are selling seems almost essential!


"AS: to be continued..."  -- please no, spare us.

CG's picture


Could/would you explain your comments?

Although not in the audio biz, my day job includes designing products using high speed DAC chips - much higher speed than used in audio products - and I can't find anything technically wrong or misleading with what has been written above.


tnargs's picture


"Digital engineers have gone through years of training where these problems were never mentioned."     Really? All those computers and no one ever realised they had to get the 1's and 0's from one place to another, using wires, with an imperfect voltage for '1' and another imperfect voltage for '0'? And they never figured out how to make it work, get those digits from place to place without corruption? Pull the other one.

"There is an entire generation of designers that lacked even a basic understanding of analog electronics."    That must explain why analog circuit performance over the last 30 years has gone all to heck? Oh wait, no, it's actually gotten better and better and gone from strength to strength. That must have happened while Hansen had his back turned, and via the efforts of non-engineers. Not likely.

"We live in an analog world"    Actually we live in a world that can be described in terms of waves AND particles. Continua AND quanta. Even the human ear and its nerves ultimately reduce the stimulae to quanta. That's NOT analog, BTW, so Hansen is making crass and childish generalisations as if they are the ultimate imperative in support of his argument, when in fact it is just crooked thinking and possibly deliberate deception, depending on how smart he is.

"How much energy is wasted delivering the data seems to have an effect on sound."    SEEMS to?  Prove it. And don't blithely say it until you have proven it. And not how much energy it takes, but how much energy is WASTED. So let me see now, if the data comes from a downloading website server in USA to me in Australia, that must take a lot more energy to deliver than if it is sitting on my hard drive at home, so it must sound a lot worse, right? Well, um, no. And then the very next sentence.....

" with increased energy usage the amount of EMI/RFI radiation also increases. This might be a reason why applications sound different."    Bitperfect applications sound different? Prove it. And Gordon, don't ask me to hold my breath while you try. Notice the clever way he swaddles the contentious part of his statement, about apps sounding different, as a presumption while he appears to be making an uncontentious statement that RF energy goes up with increased HF energy usage. This is exactly the sort of 'sandwich technique' that I described in my first posted comment.

I see I have only gotten through 20% of the article, but sadly I am out of time. But you get my drift. The thought that there is a part II is truly disturbing......

CG's picture

Fair enough, thanks.  Some of your comments are opinion, and you are entitled to that.

I do want to address one aspect that I think might have been misinterpreted.

I think that topics like energy wasted and analog world really come down to one very general, vague category and that is noise.  I don't mean the whooshing sound you might hear from your loudspeakers, but the more general term.  Indeed, even if you get down to the quantum mechanics of the world, it is hardly a digital conception of there or not there, 0 or 1, results.  There is metric butt loads of ambiguity and uncertainty. In electrical terms, that is noise.

This is where the subtleties and complexities arise, not only in digital audio systems but in fiber optic digital telecommunications systems, digital radio transmission, and so on.  You probably have seen an eye diagram on an oscilloscope, so there's no need for me to go further with that.

Audio systems still end up with at least one conversion from digital to analog electrical signals. At that point, and beyond, any form of noise has the potential for corrupting the analog signal.  This is how they are different than computers, where usually the data remains an abstraction for use by the computer.  You could argue that in a well designed system that should be so low in level that it shouldn't be audible.  But, I guess well designed systems aren't what they used to be.  There really is RFI - drag a spectrum analyzer home and take a look.  The AC mains are cesspools of noise, much of it way above the normal "audio range", where it still can have a serious effect on the audio components.  Computers pass the certification labs testing, usually, but often do so by using tricks like spread spectrum "clocks" for the switching supplies which only spreads the noise around.  The list goes on.  

Anyway, whether most people can the effects of this, or far more to the point, whether they care is a different subject.  

bsm's picture

Looking forward to a counterpoint piece.

alexandrov's picture


Especially to the cable part.

It'll be a good contribution to the cable wars smiley

ar-t's picture

I have been saying this for the last 30 years. "Digital" is nothing more than analog, with 2 voltage levels. The "digital" part is the coding, programming, and other functions, that are done on a keyboard. "Digital" design deals with the timing of how things work. But not necessarily the time domain. "Analog" designers generally work in the frequency domain, but we understand the time domain, as well. (Which is why some of us own time domain reflectometers.)  As long as "time" does not refer to the sequence of events. That is the realm of the digital designer.

The only minor point to possibly correct is at least one of us tried to tell the "digital experts", at the AES, that their proposed transmission standard would not work. They didn't listen, and had to change it, after a year or two of finding out the hard way the analog guys were right.

So, tell me again, what is the problem?

andy_c's picture

The premise of the article, "There's No Such Thing as Digital" is a great example of what philosoper Daniel Dennett calls a "deepity".  He defines this as "an apparently profound observation that is ambiguous".  He goes more deeply into this idea in this video.  Fast forward to 16:00 to hear it.

The statement here has two contradictory interpretations.  One is true, but it's trivially true (all digital waveforms are in actuality analog).  The other interpretation, that digital must necessarily be treated as analog is true only under restricted circumstances, such as S/PDIF.  If it were strictly true, you wouldn't be reading this.

Azteca X's picture

I'm with CG and Ar-t on this one.  I don't understand what one could object to in this article.  Digital is acheived with very real analog means.  Audibility is, as always, up for debate, but how can anyone be opposed to better understanding of the components used in playback and their improvement?  I'm sure people thought turntables were good enough in 1960 but we've made advances.  TV was good enough in black and white, then color, then the newfangled plasmas and LEDs were unnecessary, etc etc.  I'm not sure why everyone is so convinced USB 2.0 is the end-all of audio just because of data transfer rates.

I'm an average guy; I'm not going to buy a five-figure anything.  But a deeper understanding and exploration of these fundamental challenges should lead to advances we can all benefit from.  Someone has to take the first steps and do the R&D before we can all get it.  Even if we're talking about minor changes in sound, I'd like to think we can move closer to ideal digital playblack.

tnargs's picture

" I'm sure people thought turntables were good enough in 1960 but we've made advances."

Pretty impressive advances too, considering Hansen said there hasn't been an analog engineer sighted since 1980. OTOH turntable advances don't need engineers, it only takes a lathe operator in a country cottage in Yorkshire.

If you want to advance your audio, seriously, stop trying to split hairs in dacland and focus on multichannel recording and playback, on loudspeakers, on room treatment, and on DSP techniques. Oh, I forgot, also focus on turntables and their intractable deficiencies. If you must.

Azteca X's picture

Not feeling your combative tone but I agree those recommendations at the end are all good things.  I teach digital audio (the recording end of things, not the comp sci/EEend) at a university.  Learning how to mix 5.1, use pro equipment, treat a room: all excellent things.  And I am very curios about solutions like Acourate (backed by Bob Katz, for example) or Emotiva's use of Dirac Live in their XMC-1.  Doing your research, buying well-engineered equipment that plays nice together (no weak links in the chain) and making the most of your room are always going to be the foundations of any hi-fi setup (excluding headphones).

BUT, that being said, I don't see why we can't go "hmm" about potential further improvements in digital audio.  After reading your responses to other comments, I see what you take issue with - there were lots of sweeping generalizations in the article.  I was more focused on the underlying point that real-world conditions can have negative effects on our equipment regardless of many people conceptualizing it as a simple matter of binary code.  Think of where digital audio was 20 years ago.  We've made leaps and bounds.  I use simple gear into a Tripp-Lite strip so that my stuff doesn't blow up, and that's it.  But I am glad that there are people poking around, seeing if they can't find something to improve, even if sometimes (or most of the time, or all of the time) it's not anything I'd buy.  

marcusavalon's picture

Well yet another digital analogue can you hear the difference do I need power conditioning extremely expensive cables etc discussion. Whilst I enjoy reading the technical debates I have always found a few simple rules to apply to sound systems.

It’s really very simple when you’re buying equipment. Audition it preferably in the room you play your music in , most good hi fi dealers will gladly lend you demo equipment for home trials.
If you can’t hear a difference over what you have now then don’t buy the new equipment. Hi fi generally has a law of diminishing returns. As you go up the price range eventually the less difference you hear.

This applies equally to digital or analogue systems; audio is for pleasure and I sometimes feel we lose sight of that when discussing bits and sample rates and the almost inaudible distortions in modern electronics.

hotsoup's picture

Surely these people can hear differences after splitting the hairs of playback theory to this degree? My ears definately can't. I even failed to identify hi-rez from redbook, but a recent hearing test confirmed I roll off at 14 khz, so there's that..

Azteca X's picture

Totally.  As Michael said, if you're spending more time and money on buying gear than listening to music, stop and think.  There are things that don't measure well that people dig.  There are things that measure quite well that people dig.  I fell in love with music on a cheap Sony boombox my parents had and graduated to some $30 headphones my dad discarded after a decade of use.  I like helping my friends and family find something that gets them closer to what the music is supposed to sound like but if people are enjoying themselves, that's what matters.

All of this is why I don't understand the stand-offish comments that immediately appeared.  We're doing some interesting techincal navel-gazing here that doesn't prevent a single person from listening to music and ignoring everything read, and never buying anything any of these guys has made.  Yeesh.

Zakir's picture

How about interviewing the people from CEntrance, Benchmark Media, Resonessence Labs or Anedio - who are also known for making excellent DACs - on the very same issues?


Azteca X's picture

I'd think Dan Lavry would be an excellent addition to the conversation as his papers on digital audio bust the logical foundations of a lot of trends, such as the improper use of external clocks, recording at extremely high sample rates, oversampling etc.  Some of that probably goes against Michael's opinions, but respectfully presented contrasting viewpoints are a good thing.

Otherwise, I'd love any people from the companies that make the products on the Greatest Bits page.  Mytek, Wadia, Resonessence, Teac, etc.

Lavry obviously has a large presence in the pro audio industry and I can't help thinking Metric Halo would be a great addition, too.  They are known for impeccably clean interfaces and processing (I believe they are used by Reference Recordings and the "natural" stereo mic recording companeis).

ar-t's picture

CEntrance? Really?

deftoejam's picture

All I learned from this "article" is that the writer has never, ever competently designed a digital circuit in his/her life.  Any competently designed modern digital circuit has no "grey zone" more than fractions of a picosecond or femtosecond.

If anyone has ABX tests showing that they can distinguish between subpicosecond transitions embedded in an ASIC, please publish your results - you'll be rich if you do!

CG's picture

Gosh, there must be a load of boobs at most of the mixed signal ASIC companies as well as FPGA suppliers.  They all seem to be very concerned about variations in gate delays and slew rates, especially when a signal travels off chip to another device.  Not to mention jitter and stuff like ground bounce.  But, I would never ever claim to be a competent digital ASIC designer, so hopefully one will speak up here.  Deftoejam? Besides, the article clearly talks about what happens not within a logic chip, but when the signal needs to be converted.  

The ABX thing is a different subject entirely.

Ariel Bitran's picture


Thelefthead's picture

Not, perhaps, for the reasons the authors would hope for.  But really I'm impressed.  Sometimes you step in bulls*** and because there is just a little on your shoe it is easy to compare to everything around you and see it for what it is.  Sometimes you wade so deep into bulls*** that the only reason you can recognize it is the solid ground you can see in the distance.  And sometimes, like I find myself after reading part one, you are afloat in something so wide and so deep you can't honestly be sure if it is bulls*** or the deep blue sea.  

This article would have to be well past the comprehension of most lay readers such as I, but it does an effective job of creating reasonable doubt against some pretty strong positions on digital audio.  Sure hope that is sea water I'm tasting, but I'm not swallowing any regardless.

Hobby wouldn't be any fun without something to talk about so please carry on all.


CG's picture

I'd really like to understand what all the animosity and rancor is about here.  Why are so many folks calling this bull, ah, whatever, inaccurate, and so on?  What is the basis for this?  General mistrust of audio equipment suppliers?  The belief that equipment more expensive than (fill in the blank) is a rip-off?  Engineering experience and expertise? Something else?

This isn't a troll effort - I'm really curious why this article is causing so much angst and anger.

Can somebody help me out?

hotsoup's picture

I'll try to give you one perspective, as just an end-user of playback electronics, computers, etc. I am probably "Joe Audiophile" but obviously only one of many different kinds, as is seen ON EVERY DIFFERENT AUDIO SITE EVER.

But in all honesty, the interview gets off on the wrong foot with me in the very beginning, so the rest is called into question even though I have very very little technical knowledge to rebut. Anyway, the beginning premise:

All of this can be boiled down to a simple phrase. "All of the problems with digital are analog problems." [ ] This is the primary reason that digital audio has taken so many decades to come close to the sound of analog.

One, I don't know what the problems are with digital. Are they telling us there's problems? In my own experience, I haven't encountered any, so not sure what they're talking about. Two, I'm not sure how digital has fallen short of sounding analog. I'm listening to music on a work computer right now through tiny Arctic Sound speakers and it sounds pretty decent actually! What does "digital" even sound like? They lost me right away, in other words.

CG's picture

Thanks for the honest comments.  You bring up some interesting points.

Hopefully Michael will read your post and point you to a background article or two.  I think one of the limitations of audio and other hobby oriented web sites is that people drop in all the time.  If they aren't there from the very beginning, it's like walking into a movie after the first half hour.  If you have been here from the start, perhaps Michael can help answer your questions.  I guess he's paid the big bucks to do just that.

Michael Lavorgna's picture

...a side order of wheat toast. 

Hopefully Michael will read your post and point you to a background article or two. 

I'd recommend anything in the "Industry Voice" section of AudioStream for starters. But I think one issue we're dealing with is point of view. It should be obvious that the people designing the gear face "problems" we as listeners would never encounter. For example, the issues with adaptive versus asynchronous USB would certainly never cross a listener's mind but Gordon Rankin (and now many others) saw asynchronous USB as a solution to problems inherent in adaptive USB (mainly by allowing the DAC to control the timing of data transfer).

As far as your earlier question CG, why all the animosity and rancor, I wish I had a good answer but I only have guesses. One guess is some people seem to think that manufacturers and reviewers are in league to confuse people into buying stuff they don't need. And these people are obviously too smart to fall for this trap so they feel obligated to warn the less able. Of course this is utter nonsense and I say this with complete confidence speaking as I do from a position of authority at least in terms of knowing why I do things much more than someone who has never met me.

One of the main reasons for the "Industry Voice" section of AS is to give people access to the issues and ideas that concern the people involved in the making of the gear they may buy. 

ar-t's picture

Around 30 years ago, in what seemed to have been a previous lifetime, I was in the telecom industry. Guys like me were called "microwave cowboys". (Maybe because a lot of us came from Collins Radio.)

One day, the VP (that I had the displeasure of working for) sent my boss a letter, suggesting they send me to XYZ class, so that I could learn how "digital" works.

To no one's surprise (except for idiot VP), I  tracked him down, and 'splained to him how our network really worked. I rattled off all of the problems, we had to deal with, and explained how each and every one of them was an ANALOG problem.

So, no, I did not need to go to "digital" school.

The above interview/conversation could have been taken verbatim, from that session I had.

So, I ask again......................what is the problem? Other than some of you don't like the answers.

Next thing you know, someone will chime in, claiming there are PLLs that have lower phase noise ("jitter") than a really good crystal oscillator. Only a digital designer would say that. (Because, in fact, I know one that does. Mainly because they do not understand how "jitter" is a function of both carrier frequency, and the frequency of the jitter signal. And how you can fudge the data, to say darn near anything you want.)

Digital designers can read analog app notes, and data sheets. Too bad they know as much as the average layman. Yet, they are prolific, on all manner of forums, and fill folks heads full of disinformation. When folks who really understand how it all fits together comes along, and tries to set the record straight, some of you can not handle it.

It is not our fault you have been fed nonsense. Do not hate us for trying to explain how it really works. Even if it does not fit into your present sphere of knowledge.

Deal with it.






CG's picture

"When folks who really understand how it all fits together comes along, and tries to set the record straight, some of you can not handle it."

Didn't that Cuckoo's Nest guy say that in another movie?

Airfla's picture

Frankly, IMO, the suggestion that there is no such thing as digital is a bunch of malarkey! Sorry, Steve, but you are looking at things from the wrong end. You have to start at the source, not the reproduction end. What is placed on a CD, DVD, hard drive, or whatever, is a the result of sampling the original analog signal and representing that signal in digital form. It consists of 1s and 0s. Whether some form of analog electrical signal is subsequently used to extract or interpret the digital data misses the point. Obviously, a digital music file is fundamentally different from the continuous analog representation in the groove of a record. The whole reason for increasing the sampling rate and recording a larger sample is an attempt to more closely approximate the continuous nature of an analog signal.

CG's picture

All very true!

But, and I think this is the point, the actual real world electrical transmission and conversion process is analog.  The zeros and ones are represented by analog voltage levels at discrete time intervals.  As such, they still follow the laws of physics and are subject to imperfections such as noise, less than infinitesimal rise and fall times, and time variations.  In addition, the electrical processing bits - ahh, portions - are still the victims of power supply imperfections, parasitic reactances, and so on.  If this was not true, then the semi-conductor business would be easy, and unprofitable, because the very first 4004 chips would be powering your computers today.

Howard Johnson - not the ice cream guy - has made a living writing and teaching about this to digital hardware design engineers and technicians.  Other guys like Henry Ott and Ralph Morrison have done the same regarding the noise issues around digital (and other) circuits.  I have no idea if these guys even know of the existence of so-called high end audio - that's certainly not who their usual audience is.

Digital anything is pretty much an abstraction.  The real world is analog in nature, even down to the quantum level.  Digital computation, transmission, and the rest is done for one reason - it is really convenient and practical.  The electronics don't need to be linear, so they are much less expensive to manufacture and use.  Much more compact, too.  Great stuff.  But, using it well and with high performance is not as easy as just plopping some chips in a board and entering the programming code.  Really.

If you don't want to believe these guys who happen to be designing and selling audio gear, that's your choice.  Or if you believe that this level of engineering is a bunch of baloney, that's fine, too.  (Why you'd then be visiting this web site is an interesting question...). Instead, go check out some of the guys like Johnson and Ott.  They have web sites.  Even go investigate the application sections of high speed digital to analog converter data sheets.  The manufacturers for those have web sites, too.  All for free.

Vigna ILaria's picture

<<Frankly, IMO, the suggestion that there is no such thing as digital is a bunch of malarkey!>>


C'mon, man.  You surely cannot be unaware that the purpose of a headline or a hook line is to grab your attention, and is usually not to be construed too literally.  I wrote a post on my own blog a while back to the effect "There's no such thing as Analog".  Doesn't mean I disagree with Hanson et al, or that they would disagree with my post (if indeed they ever even saw it!).  The Original Post merely points out that there are significant analog design challenges to be overcome in dealing with what are commonly considered to be digital problems.  Big deal!  But it was a valid and - all things considered - a useful piece.


Finally, Airfla, the point you go on to make neither follows from, nor is particularly germane to, the OP.

ivan's picture

It seams that many don't understand the difference between terms digital logic, digital signal, analog signal, digital audio signal, difference between 4 types of signals which are continuous or discrete amplitude and continuous or discrete time signals, signals vs. functions, logical layer vs. physical layer. Any such discussion without at least understanding of above is futile.

Airfla's picture

"C'mon, man.  You surely cannot be unaware that the purpose of a headline or a hook line is to grab your attention, and is usually not to be construed too literally."

Of course!

What the article boils down to is a well explained reply to the objectivists who insist that bits are bits and therefore must sound the same. Unfortunately, that "debate" will probably go on forever, regardless of whether engineers are involved. It is because we are talking about the reproduction of music - which engages our senses - as opposed to raw data, that the issue arises. Digital is still digital, however, notwithstanding the fact that electricity itself is fundamentally analog in nature.

But, one does have to wonder why those "digital" engineers' hearing is so poor. smiley

ar-t's picture

"One guess is some people seem to think that manufacturers and reviewers are in league to confuse people into buying stuff they don't need."

That is funny. Someone thinking I am in cahoots with a reviewer. Any reviewer.

Guess they don't know me. I'll stop at that, before they give me the boot.

darthlaker's picture

Joe Rasmussen and the late, great Allen Wright found this out some time ago.

I have heard their upgraded players and they can compete with players that sell for FAR more $$$$!