Friday 26 September 2014

MUSINGS: Stereophile's "Recommended Components" & the shift to objectivism.

The other day, I was perusing the Steve Hoffman forum and ran into this thread. Yup, Stereophile's Fall 2014 Recommended Components list is up.

A thread poster noted that the Sony Playstation 1 remains on the list again. And it's a beautiful reminder of how questionable a list like this is.

Ridge Racer! This first generation game fits in the 2MB RAM of the PS1. After loading the game you could take out the CD and put in your own (audiophile) music while racing... Nothing like chillin' to some Diana Krall while pulling power slides :-).
As someone who has listened to and tested the PS1 (my objective results are about the same as Stereophile's), I can say without a doubt that this makes no sense even though they list it as Class C (lower fidelity but "far more musically natural than average home-component high fidelity"). The device has been discontinued since 2006 worldwide but nobody has said good things about the sound of the later PSOne iterations (and the PS2 came out by 2000 already). The user interface is atrocious - skipping through tracks with the PS1 controller? Hook up to TV to see what track you're on? Pop-up plastic lid? It's not a good looking device - all plastic, cheap gray, ugly controller wires... Has a paucity of features: no digital output to hook up your own DAC for example. Is somewhat noisy in operation and has reliability issues (I know, because I traded in a really well constructed 3DO FZ-1 for an early PS1).

Which then leaves only the sound which is objectively noisier than most cheap CD players and has a characteristic uneven frequency response curve starting around 2kHz and up.

It's a beautiful example of how a particular reviewer (Art Dudley) took an idiosyncratic subjective interest and spun it into something which to this day still "graces" the memory of audiophilia.

Objectively it's far from ideal and subjectively I found it sounded fine but nothing special... But isn't being a "Recommended Component" an achievement to suggest special redeeming qualities found above the equipment's peers? Even if one believes that the standard objective measurements typically performed like noise floor, harmonic distortion, crosstalk, etc. are incomplete, how is it ever "good" to promote a device that can't do these basic parameters of accuracy well? And to even mention something like this in 2014!? I might as well happily recommend my <$100 JVC 5-disk CD changer bought at Costco in 2000 over the PS1 in every way I can imagine - including having cleaner sound quality and the option to hook up a DAC through TosLink. 

More recently, consider the 'promotion' of something like the Lector Strumenti Digitube S-192 as a Class A Digital Processor. Well, at least they didn't list it as A+! But how is this a "good" DAC when objectively it's a fact that this thing can't even reproduce down to the 16th bit accurately? That "192" in the product name implies that it's capable of 192kHz "high res", but what's the point when the output noise level is so high? If this was 1995, then maybe it'd be competitive with other DACs; but in 2014, isn't this a bit of a joke? Just because again, a certainly reviewer (Art Dudley) seems to like this type of inaccurate sound? (Oh, pardon me... Music reproduced with this kind of sound.)

As others on the forum post had suggested regarding the Recommended Components list, I agree that it represents a form of vacuous entertainment (I see the word "porn" offered). While I of course agree that many of the A+ components are excellent, there's clearly much that's questionable and I surely hope few readers take these lists seriously!

In cases like the Strumenti, I wished Stereophile took the approach of saying that the objective measurements supersede the subjective opinion because the facts say so (oooohhh... scary thought...). I know Mr. Dudley is well known, has worked in the industry for years and has heard a lot of good quality gear... But I know nothing of how well he hears at his age, and whether he should hold a Golden Ears certificate. Nor do I agree with the philosophy that subjective reviewers somehow have the task/responsibility of tapping into and reporting on "musicality". Please, let the artist do his/her thing, let the gear be accurate, and let the listener judge if what the artist did sounds musical or not. As discussed previously, purely subjective reviews I believe have limited utility once equipment is tested with objective scrutiny in regard to audio quality. This should not be surprising.

Don't get me started on the Cables or many of these "Miscellaneous" recommendations :-).

Despite my criticisms, I still think Stereophile is the best audio publication these days. The fact that they are the only ones in North America (with wide circulation) to attempt balance is to their credit. And the fact that it irks me enough to bother writing this obviously also means I care enough to wish that it could get better.

Here's a thought. In my opinion, change the list to "Recommended Current Components" to identify that this list is meant to contain equipment currently available or reviewed over the last few years. The PS1 should really not be there. Then create a supplemental list of "Recommended Vintage Components" which contains a running list of all the gear previously recommended over the years. Forgo the paragraph blurb in the Vintage list but identify which past issue it was reviewed; maybe create a link to a $1 PDF for purchase of the review... Might as well make a few bucks and I for one probably would be happy to purchase a few at that price point which I think is very reasonable considering how cheap an electronic subscription costs!

PS: Speaking of using the PS1 as a music player, here's a cool DIY site.


This brings me to some final observations and parting thoughts for the week. I'm definitely into major speculative musings here.

I think the tide towards "more objectivism" has started. The forces of change are many, some of which have been highlighted by AudioPhil's personal journey. I suspect his trajectory isn't all that uncommon; a shift over time from the grasp of the so-called "high end" of subjective hype and superficial reputation / appearance, into a realization that "good sound" these days should not be determined by a fascia made of aeronautical milled aluminum nor has anything to do with extravagant cost.

The rationale I believe is fourfold:

1. Technology has advanced and engineering has easily reached a level where affordable equipment can surpass human auditory acuity. This has been the case for more than a decade now where reasonably well engineered devices can achieve >16-bit resolution as a concrete example. The cost of a device that can objectively achieve this should be <$500. A simple DAC like the <$200 AudioEngine D3 or my AUNE X1 DAC (<$300) are examples of this at low price points. That's just plain reality. Good, accurate sound should be a pre-requisite for "recommended" gear by default, and if one is recommending based on a "colored" sound (tube sound, NOS DAC sound), just say so.

2. I believe the Music Industry will start "objectivisation" of music further. As much as I feel it is misguided (vis-à-vis the 16-bit vs. 24-bit test) to sell more remasters in the form of a veiled attempt at promoting sound quality, the marketing departments are gradually "educating" the masses about lossy vs. lossless vs. hi-res. And they're doing it using the lowest common denominator - promoting the parameters of the file container (simplistic idealization of high bit depth and samplerate while demonizing MP3/AAC). Look at how Pono idealizes "24-bits!" and "192kHz sampling rate!". I believe soon, digital equipment reviewers will need to prove that indeed the piece of gear is capable of benefiting from the greater bit-depth - the only way would be at least a partial acceptance that measurements are necessary. This isn't all bad since it will promote more accurate devices. In time, I believe purely subjective reviews will ultimately lose readership; essentially becoming an extension of the advertisement arm of the Industry. (I believe those glossy picture-filled audio magazines are already there.) Depending on the desperation of the industry to promote the high resolution digital meme, there will be continued push towards a (again misguided) comparison with vinyl in order to sway those who have special reverence towards all things analogue. There might even be increased animosity between the two camps to gain market share.

3. In the big picture, generational dynamics will IMO strike a blow against subjectivism. As the Baby Boomers age, diminish in societal influence, and depart, those that come after will take up the audio hobby in their own way with their own values. The so-called Gen X and Gen Y (Millennials) are without question more technologically savvy. Raised in an environment witnessing the rise of digital in all areas of communication and media since a young age (and noting benefits of the digital age without undue fear or sentimentality), the new generation will gradually dilute analogue biases and practices. Something as simple as lossless file formats being free from multi-generational copies or that the sound of FLAC is no different than WAV/AIFF (this seems to be lost on folks like Cookie Marenco) will be as obvious as swiping a touch screen. In any other area of digital gear evaluation, it is well accepted to use objective measurements (is that SSD faster than HDDs? How much faster is USB3 vs. USB2? Does the Retina iPad Mini display look clearer than the new Galaxy Tab? So how good is the color space rendition of that new monitor?). For decades now, computing sites like AnandTech or Tom's Hardware have done reviews demonstrating objective ability. Look around your local bookstore, at least around here, gone are the 'generic' thick monthly computer magazines like PCWorld and in its place are either enthusiast magazines like Computer Power User (chock with reviews using objective measurements) or the various "iPad for Seniors" special editions. There is no reason audio hardware should be spared from a greater level of scrutiny. Of course, I do believe subjective opinions have their place and would be valued when it comes to usability, look & feel, verification that the sound isn't unexpectedly awry, some music recommendations, interesting anecdotes, and of course general entertainment value.

4. With generational changes as big as what we are likely to witness with the Boomers,  there will come societal changes in terms of wealth and values (among a myriad of other issues like health care entitlement, debt obligations, environmental concerns, even the fabric of societal morality). For example, I think most of us would not argue with the idea that there's something wrong with how things are going with the economy. Disparities and inconsistencies appear the norm rather than the exception all over the place. It will not be a surprise to see a shift in the appetite of debt and consumerism to one of saving and maintaining wealth in the decades ahead. This will change our values and attitudes about luxury goods and what really is "good". Although a miniscule piece of the big picture, tides of change will not spare the "high end" audio industry. These are massive issues and not ones I can fathom discussing with any sense of justice to the topics in this humble blog.

No, I don't expect these themes to take hold overnight. Fundamental shifts almost never change quickly (sometimes they do during times of revolution of course) but these are some of the trends I'll certainly be looking for in the days ahead. Hey, maybe in 10 years I'll come back to this post and review the scoreboard assuming I care about audio hardware at that point!

Until then (2024), get a nice seat in front of your favourite audio set-up. Put on some good tunes. Enjoy the music. :-)

Friday 19 September 2014

MUSINGS: Vinyl Paraphernalia & Good Old (Free) Vinyl :-)

As I mentioned before, I've been going through the bargain bins at the local LP stores and it has been great finding stuff I hadn't listened to for years! Tonight, as I'm typing this I'm getting reacquainted with Henry Lee Summer's I've Got Everything album for example [recent article on Summer]. It indeed has been decades since I've heard "Hey Baby"...

Yup, old memories of high school - Gen-X and proud of the 80's :-)

Okay, on to the main topic for this post.

I noticed over the last month how getting into vinyl resulted in an accumulation of "paraphernalia". I've got a little collection of "things" now on my music rack that wasn't there before. Plus I've got a compartment where I keep my albums for a few of these things. It's all part of the ritual of maintaining a clean LP collection. I suspect you can tell the "serious" vinyl audiophiles from the "casual" based on whether they have these items hanging around; many of which I would consider essential! I'm sure this is 'old hat' for you vinylphiles already, but for those curious, without further ado, let's have a peek at what I've accumulated:

I. Cleaning Supplies:

Without a doubt, this "class" of products is essential. There's just no way to experience decent LP sound unless it's clean.

For dry cleaning, I started with the Vinyl Styl anti-static carbon fiber brush. It's relatively cheap at $15 or so and good to brush off surface dust as the disk spins on the platter before dropping the needle. Often dust is just moved around and you end up with a "line" of dust unless you direct the dust off tangentially. I've also seen a demo where the brush is moved medially towards the spindle to touch the central metal part. Supposedly this discharges the brush allowing it to hang on to the dust particles. I personally have not found this consistently does the job.

There are of course many such brush products out there. I've heard of folks complain that carbon fiber brushes can leave "hairs" or micro-scratches on the LP. I have not had either of these problems. Just don't press down too hard when cleaning the vinyl surface.

To the left in the clear plastic box is the Nagaoka Rolling CL-1000. I got this off eBay for about $120 from Japan shipped. It's not cheap. Basically it's like a fancy sticky (elastomer) lint brush meant for dry LP cleaning. I have wondered if the cheap sticky roller from the local store would do the trick but too chicken to try :-). In any event, this thing works quite well. I don't know how deep in the groove it can get but the ability to lift dirt and dust off is better than the plain carbon fiber brush. I had noticed with the first usage that I saw a little bit of residue which was removed with a second round of cleaning and no problem thereafter - I think it may have come from the clear plastic protector wrapped around the elastomer that had to be peeled off. I usually will use this on new LPs just to remove the small amount of dust/particles rather than doing a wet clean. Static charge builds up when rolling so make sure the environment is clean - I often will do the rolling on top of an anti-static inner sleeve. (I've noticed some much cheaper ones like the Stop-a-Clicks; I presume this would be fine at a much lower price point.)

The yellow box is of course the Spin Clean. IMO wet cleaning is essential! There's no way I'm going to play the majority of my used purchases unless they've been through a wash cycle. The Spin Clean Mark II works great. I have had some albums cleaned at a local store with their VPI 16.5 machine and I thought the result was really quite similar so long as I took care with the Spin Clean. I have not had any issues with scratching or abrasions. A few observations / suggestions:

1. Use distilled water especially if your region has high mineral content 'hard' water (not really a problem here in Vancouver).

2. After the wash, hold the LP over the Spin Clean to let the residual water drip off the disk before drying for about 10 seconds. This reduces the amount of fluid to wipe off and noticeably less water spots after drying.

3. Buy some good, soft, absorbent microfiber cloths to use for drying. The Spin Clean kit comes with a couple of rather substandard drying wipes.

4. I never use much of the provided cleaning fluid. My formula: fill the Spin Clean up to 90% distilled water, 10% with isopropyl alcohol, and just 1 cap of the starter kit fluid (they recommend 3 cap fulls).

5. Don't let the reservoir fluid get too dirty... I usually wash less than 20 used albums before throwing the fluid out.

II. Needle / Stylus Cleaner:

Have to keep the stylus clean of course. On the right is the "free" stylus brush provided in the package with my Denon DL-110 cartridge. Does the job with very delicate fibers.

On the left is the Onzow ZeroDust. Removing the plastic cover reveals a piece of convex gelatinous substance you can gently "drop" the needle on, removing any dust or pieces of vinyl stuck on. I first saw one of these at AudioPhil's place and liked it - easy and quick.

III. Calibration Paraphernalia:

Then I got all this stuff:

Precision electronic VTF scale. Good down to +/-0.01g. The manual scale on the Technics SL-1200 standard tonearm counterbalance is quite accurate already down to about 0.1g from experience. It's nice to have this for confirmation though plus it's not expensive (~$20).

Without question, the most arduous task with turntable setup is getting the cartridge aligned. A reflective alignment tool such as the ruler-like device to the right is helpful. However, with my Technics, the freely-available-to-print Baerwald Arc Protractor off Vinyl Engine is all I really need. Just make sure you print it out 100% with no print scaling to keep the dimensions accurate and punch the center spindle hole accurately.

I got one of these inexpensive ~400gm record clamps off eBay from Asia. I don't buy noticeably warped records so I don't use this much but there is a convenient spirit/bubble level on top to make sure the turntable is flat. The 50Hz stroboscope is useless for me here in 60Hz AC land.

Some people will use things like USB microscopes to check the Stylus Rake Angle (SRA) for VTA calibration. I haven't gone to this level of fine tuning yet (and possibly never will plus I really doubt it's all that important since slight warping is common yet I don't generally hear any difference when the needle tracks over those areas!). One idea has been to use a macro lens on my dSLR to take close up pictures using a well aligned tripod... I'll maybe give that a try.

IV. Sleeves:

After cleaning used vinyl, there's no way I'd put them back in the original old record inner sleeves. So far, I have found the Mobile Fidelity "Original Master Sleeves" a must have. They're soft, thin, and I have not had any problems with powder residue some have complained about. At about $20-25 for a pack of 50, they're not cheap though. One gripe I've had with a number of new 180g remasters (like my new Guns N' Roses Appetite For Destruction) is the shiny paper used without any soft inner lining. Often with the tight fit of thicker vinyl, the paper sleeve almost guarantees abrasions when putting the LP in or taking it out. Disappointing and all too common to take out a new LP for the first time feeling the resistance of the inner sleeve when pulling out and finding abrasions already on the vinyl.

Then there's the transparent outer sleeves which will keep the outer artwork safe from scratches. I've been able to find good 4 mil locally for about 25 cents a piece.


Well, that's not too long a list of paraphernalia I suppose... But it's certainly more than one ever needed for a CD collection (all I had was a soft microfiber cloth to wipe off smudges and a few extra jewel cases). Taken together, there's at least $300 of "stuff" purchased; not counting the extras for the sleeves and obviously I'm not buying anything extravagant here. Of course, not all of this is essential, but significant considering the price of my used Technics SL-1200 M3D (only around $500). Something to keep in mind for those getting into vinyl. However, the bargain used LPs (at least a lot of the 80's stuff I like) can be had for really cheap!

I'd love to hear what other items you've found useful with your LP rig... How much difference do you think a vacuum record cleaning machine makes compared to washing by hand or a relatively inexpensive system like the <$100 Spin Clean?


To end off this post, I remember awhile back reading one of Stephen Mejias articles in Stereophile where he observed that when others realize one has a record collection, friends and associated will start offering up LPs they don't listen to any more... Indeed, I was fortunate enough to have a friend offer the following:

Interesting early Beatles pressings from Asia purchased when first released - Abbey Road and Let It Be appear to be pressed in Hong Kong, With The Beatles from Malaysia, and Sgt. Pepper's from Singapore. I'm not sure about the Red and Blue compilations.

I have both an early Canada pressing of Abbey Road and later pressing of Let It Be from the mid-1970's for comparison. As best I can tell, the Asian Abbey Road sounded cleaner and Let It Be was about the same. I compared Abbey Road with the recent 180g LP remaster and not unexpectedly, these older pressings sound softer, and perhaps less detailed compared to the more compressed and digital remastered LPs. This is the same impression listening to an early Dutch pressing of Dark Side Of The Moon (thanks Ingemar!) compared to my new 180g remaster. It's subjective which mastering one prefers of course but there is something special to be said about holding and playing an album of historical importance physically created before I was even out of diapers. As I have noted before, these properties of a physical object add to the joys of vinyl collecting irrespective of sonic quality (obviously I'm not getting the same vibe with new digital remaster LPs).

Finally, I also received the following box:

The Beatles E.P. Collection of 45's in both original mono and stereo! Mint vinyl condition! Thanks Paul :-).

Have a great weekend and week ahead. Gotta run off to listen to some "classics" now...

Friday 12 September 2014

MEASUREMENTS: Microsoft Surface Pro 3 Audio.

Over the last couple years I have been using my ASUS Taichi ultrabook as my daily work/business traveller laptop. I've certainly appreciated the ultrabook form factor and speed! Although these little devices aren't cheap, there's no way for me to go back to anything larger these days in terms of a full function portable work machine...

"Unfortunately", I felt the need to upgrade the daily use machine as I was starting to run into headroom issues with 4GB RAM and needed something with substantially more battery life for the longer trips. Enter the newest member of the Microsoft Surface family with the Intel Haswell core - Surface Pro 3. Sure, I could wait another 6 months and get the Broadwell maybe in early 2015 but like anything in technology, you can't wait it out forever when there are true advances being made.

I got the i5, 8GB RAM, 256GB SSD model. I suspect this will be the most popular model of the i3/i5/i7 versions as a reasonable compromise between features and price. I was actually looking at trying the i7 model but I couldn't find any locally! I believe the i5 was released about a month and a half ago and the i7 just came out so demand was higher. In any event, the i5 should be more than adequate and I hope there will be some benefits to a less speedy model in terms of heat production, noise, and maybe improved battery life.

With blue Type Cover 3.
I'm not going to bother with a full review. You can find plenty on-line like AnandTech, or IBT. Overall I do agree with the reviews. It's certainly not the perfect tablet - too heavy and large still for casual browsing and media consumption. And it's not the perfect laptop/ultrabook for the price. It is however made very well with a nice magnesium case which is solid with a sturdy kickstand. It's certainly very easy to travel with, and the newest Type Cover 3 functions decently as a keyboard/trackpad. I actually was interested in the first Surface Pro when it came out in early 2013 but there were too many issues at the time with heat, battery life, and keyboard/mouse issues that I went with the ASUS Taichi then. With the improvements since, I thought I'd give this iteration a try.

Just a few quick comments:
1. The 3x2 screen is different. First time I've bought a non-widescreen (~16:9) computer/monitor in the last decade. For a small device like this, it works well. It's a little smaller than standard letter paper size. I love the screen contrast and 2160x1440 resolution - almost as high as my 27" main monitor! Note that some old software might not scale appropriately leading to ridiculously small fonts which might make it tough to use the touch screen accurately.

2. The digitizer pen feels good and works well. I started using OneNote more and can appreciate the capabilities. Seems to work well so far taking notes in meetings. Pressure sensitivity was good and allows some casual sketching (not that I'm much of an artist!). I find myself sometimes accidentally pressing the buttons on the pen which I need to get used to.

3. Mixed feelings about the kickstand and "floppy" keyboard. I'm actually typing fine on the Type Cover 3 keyboard - speed about the same as my previous ASUS ultrabook. The fact that there's no spacing between the keys increases the chance of inadvertent typos. What's different is the center of gravity and feel of the base. Normally the keyboard is the base of the laptop rather than the lower edge of the slate + the kickstand being the supports with the center of gravity pushed distally. It's not a big deal on a table since the kickstand is very stable; but feels initially strange and one has to be careful when placed on the lap - it can be easy to tip over with leg movement. This "lapability" issue is known and at least the kickstand can be adjusted further to improve balance but this also extends the front-to-back length.

4. Please Microsoft, consider two USB ports in future versions; I'd hate to carry around a hub. Sometimes it's nice to plug in my Logitech Unify receiver for an external mouse/keyboard and still have another USB for something like the Dragonfly or AudioEngine D3.

5. I'm glad they're using the DisplayPort for external monitor output. Easier and cheaper for analogue VGA adapters. Support for 4K, etc...

6. One beneficial result of the kickstand form factor is that it's cooler on the lap since there is no contact with the area around the CPU and heatsink. The fan is still audible with moderate to heavy computing but at least the heat is dissipated away from where there's physical contact.

On to the headphone sound...

For such a small device, the built-in speakers are fine and I do believe sounds better than the older ASUS Taichi. The first thing I noticed when looking at the sound playback settings is that the hardware is identified as "Realtek High Definition Audio" and the maximum samplerate possible is 24/48! I tried the latest Realtek HD Audio drivers here (R2.75) as well and still 24/48. It looks like previous versions could do 24/96. Though my preference would be at least 24/96 these days, I don't believe this is a problem; surprising nonetheless since almost all devices should be able to handle 24/96 by now. Perhaps the hardware is capable but there's something with the OS settings I haven't adjusted yet (using the current stock Windows 8.1 installation that came with the machine).

A look at the oscilloscope graphs:
1kHz Sine 0dBFS at 16/44.

1kHz Square 0dBFS at 16/44.
Oscilloscope indicates that at 100% volume with 0dBFS signal, there's no clipping. Nice. Also, channel balance is excellent! Maximum output voltage is ~1.6V. Not capable of playing music as loud as the Dragonfly v1.2 or AudioEngine D3 so make sure to go for higher sensitivity, less power-hungry headphones.

The 16/44 impulse response looks like this:

As expected, standard symmetrical linear phase digital filter. Less than usual pre and post-ringing suggesting earlier roll-off in the frequency response.

Time for the RightMark 6 results. Here are the 16/44 results with a few other devices for comparison. I used the usual measurement chain:
Microsoft Surface 3 headphone out --> shielded phono-to-RCA --> E-MU 0404USB --> shielded USB --> Windows 7 laptop


The Surface Pro 3 is in the first column, followed by both the Dragonfly and AudioEngine D3. I then threw in my two compact portable devices the Nexus 5 phone and Nexus 7 tablet. Followed by the Transporter and Oppo BDP-105 as higher end devices. Apart from the stereo crosstalk being a bit "weak", we're seeing that 16/44 is not a problem for any of the devices these days. The defining factor likely would be the quality of the headphone outputs (eg. power, impedance characteristics) rather than accuracy of the DAC. As usual, a few graphs (click images to enlarge):
Frequency Response - Surface 3 slightly earlier high-frequency rolling off than others.
Noise Level
Stereo Crosstalk - unusually high for Surface Pro 3.
Since 48kHz is the highest samplerate supported, it's worth measuring since this would be the natural downsampling level for all the 96 and 192 kHz music. I don't do many measurements at 24/48 but I'll throw in the results from the Squeezebox Touch and Receiver from awhile back for comparison as well as 24/96 results from some laptops I had measured last year to show their 24-bit performance:

Noise level and dynamic range suggests that the Surface Pro 3's headphone output has about 17.25-bit dynamic range. With 24-bit data, the best devices I have like the Transporter will give me a measured result around -113dB (almost 19-bits) which is also likely a limitation of the measurements using the E-MU 0404USB. Distortion characteristics of the Surface 3 are comparable to the Touch, but again, we're seeing quite high stereo crosstalk of -66dB which is poor for digital devices.

Despite the 48 kHz limitation, it's nice to see that the Surface 3 is capable of better dynamic range than my old Acer Aspire 5552 laptop and ASUS Taichi ultrabook. From those tests last year, I was quite impressed by the Apple MacBook Pros and I see that the Surface 3 measures about the same as the old MacBook Pro from 2009 except for the poorer stereo crosstalk.

Again, a few graphs for completeness (only the 24/48 results):
Frequency Response
Noise Level
Stereo Crosstalk
Let's finish off the objective stuff with the jitter spectra - as usual, the Dunn J-Test; 16-bit and 24-bit versions:

While the 16-bit J-Test results aren't the cleanest nor does it look ideal, it'd be hard to make a case for jitter audibility. The 24-bit results looks very nice. Overall minimal "skirting" around the primary frequency.

I'm not going to spend much time on the subjective descriptions here... The fact is, when I'm traveling, I just don't see why I'd need the full high-fidelity experience. I'm only likely ever going to be listening with this machine for any length of time on plane flights where the background noise is high and I'm likely distracted anyhow doing work. Suffice it to say, in an atypical and wholly unrealistic situation for me sitting in the quiet of my home with my Sennheiser HD800 headphones plugged into the Surface Pro 3, the sound is excellent. It doesn't provide as much power as the recently measured Dragonfly v1.2 or AudioEngine D3 so don't expect it to play very loud. It does however convey the resolution I'm used to like Donald Fagen's immaculately produced "I.G.Y." from The Nightfly. I had a listen with the AKG Q701 as well which is one of my more inefficient headphones. Again, the detail was excellent but perhaps a bit bass shy and at maximum volume, it's just capable of slightly louder than my usual listening level. This volume level would be fine with my high sensitivity IEM headphones I usually bring on my travels though.

Although stereo crosstalk is high compared to other digital devices, subjectively I do not believe this is a problem. Remember that vinyl has stereo separation typically between 20-40dB only and it can still sound excellent. It's one of those things where technical specification strongly exceeds real-world necessity (I would still like to see "perfect" execution of course from an engineering perspective).

I'm impressed by how much technology can be packed into a small package these days! As I write this last bit, I have been using the machine for close to a month now and it's performing very well. The small form factor is convenient and shaves a few ounces off my work briefcase compared to the previous ultrabook. As need for increasing CPU speed appears to be plateauing and monitor resolution really doesn't need to get any better for smaller devices, it is going to be the form factor, weight, and usability that matters. While not ideal at this point, the Surface Pro 3 is clearly taking a step closer.

As for the sonic measurements. Stereo crosstalk is high for a digital device and I'm surprised by the 48kHz sampling rate limit. It does handle 24-bit data with decent dynamic range rivaling the old Apple MacBook Pro I have. Compared to previous Windows laptops, despite the size, it does quite well keeping the noise level low.

To end off, a few thoughts over the last couple weeks:

1. Sometimes the darn 'Connected Standby' sleep feature on the Surface Pro 3 makes the machine not wake up! Look here for a thorough article on this issue. It happened to me twice in the 1st week of ownership. I turned off the Hyper-V feature and thereby disabling this "feature". I've since turned Hyper-V back on and have not noticed a problem in the last 10 days... Maybe there was some software update that fixed this.

2. Here's a serious question/suggestion for high-end DAC manufacturers. I know HDMI costs money to license yearly. How about using the DisplayPort as a standard for audio data transmission - a royalty-free VESA specification? I've always wanted a high-end multichannel DAC/streamer (attention paid to resolution, lower jitter, etc.) - something like the Transporter with robust server system that can handle *all* my music files - both stereo and multichannel (maybe even DSD stereo/multichannel but that's lower on my priority list). What I'm currently doing with sending multichannel via the computer's HDMI to the Onkyo NR-TX1009 receiver works and will get me multichannel sound. But the Onkyo DAC isn't the best, occasionally I will run into disconnections and I would love to see unification on the software side where something with the power of Logitech Media Server can be used to serve both stereo and multichannel! The DisplayPort has the capability for 24/192 multichannel no problem and presumably cheaper for manufacturers without worrying about the licensing costs.

3. There's a guy who claims to be able to ABX high-resolution audio files as well as ABX using the Bozza track from the 24-bit test. He claims to be successfully doing it with an HP Zbook 14 laptop and Etymotic ER-4P. Given what I have seen with measuring the laptop headphone outputs, I'd be very curious what that HP Zbook 14's output quality looks like to confirm that it is capable of >16-bit resolution. Furthermore, I have the Etymotic ER-4B (as discussed in the Dragonfly measurements) sporting higher 100-ohm impedance - it's good but I can't say I've ever considered it that good in conveying sonic detail. Not saying that the guy cannot tell the difference but I would be a bit cautious given the equipment used and posting a "successful" ABX log is easy; would have been better if he responded to the survey and got 3/3 in a blind test... Needless to say, in my 24-bit test, I specifically asked folks not to just use the computer motherboard/laptop headphone jack simply because it more than likely outputs compromised sound compared to something superior like even the inexpensive Dragonflies of this world (if not a fully external powered DAC) if one is serious about trying to listen to high resolution audio.

That's all for now.

Have a great weekend and week ahead everyone!

Thursday 4 September 2014

MEASUREMENTS: Digital Audio and the PlatterSpeed "Wow & Flutter" App

Shortly after my last post on the wow & flutter measurements with the Technics SL-1200 using the 7" test disk, Frans suggested in the comments a test using a CD to demonstrate what the results would look like using digital devices.

Great idea!

So, I whipped out good old Adobe Audition and generated a -10dBFS (same level as the Test LP signal) 3150Hz (for 33.3rpm) sine wave. I burned it on a standard Maxell CD-R - first time in a long time I've burned an audio CD!

To purposely not do anything special to reduce the "potential" for jitter (NB: I don't actually believe this anyway), the disk was burned at 48x on an older LiteOn iHAS DVD burner which I got either in late 2011 or early 2012. I did verify the burn to make sure the data was readable.  I used my electrically "noisy" quad-core home assembled i7 workstation to do the burn as well. Despite the strong temptation, I did not use any green "Stereophile recommended" StopLight pen to color the rim of the CD to improve the sound :-).

For the graphs, remember to look at the scale on the left to get a sense of the magnitude of frequency variation. I've aimed at measuring over the course of ~60 seconds.

To start, let me just show what the results look like with my network devices streaming off my server computer before I throw the CD into a few spinners:

Logitech Transporter - balanced analogue output, wired ethernet connection to music server (main soundroom system with Paradigm Signature S8 speakers):

Logitech Squeezebox 3 (Classic) - RCA analogue output, wired ethernet connection to music server (living room Tannoy MX2 bookshelf speakers):

Logitech Boom - wireless connection to music server at 30% signal strength 2 floors apart (built-in speakers):

Home Theatre PC to TEAC UD-501 DAC via USB using JRiver Media Center 19 to stream the shared file off my server machine in another room in the house (essentially the typical PC-DAC setup):

Alright, enough with the streaming devices... Time for some CD spinners now playing the burned Maxell CD-R...

Panasonic Blu-Ray DMP-BDT220 player (2012 model) in soundroom connected via HDMI to Onkyo TX-NR1009 receiver with Paradigm Signature S8 speakers:

Windows 8.1 Intel i7 computer with CD played off LiteOn iHAS DVD burner to ASUS Xonar Essence One DAC (USB) with desktop AudioEngine A2 speakers. To make this even more "challenging", I have 8 computing threads running doing WAV --> FLAC compression just to create 100% CPU load with heavy hard drive activity:

"Lo-Fi" Sony CFD-S05: Finally, my lowest fidelity device that plays a CD; an all-in-one cassette / CD / radio. About $70 and worth every penny just to play the occasional cassette tape :-).

So, what can we say looking at the above graphs and numerical summary? Exactly what the jitter measurements over the last year or so suggests. Timing anomalies as can be detected in frequency shifts are minuscule in the digital world compared to what is seen with a turntable set-up. Dunn J-Test utilizes detailed FFT analysis to look for tiny sideband distortions which typically show up below -100dB with most decent DACs these days. There is a world of difference between what's found with the J-Test compared to the timing errors with typical turntable measurements as reported by tests like PlatterSpeed.

Looking at the mean frequency (remember, target exactly 3150Hz), every one of the devices achieved essentially perfect scores except for the inexpensive "lo-fi" Sony all-in-one (average 3153.7 Hz). Even with the Sony, my guess would be that this is due to the low fidelity speakers or "defective by design" (remember the poor frequency response) rather than an underlying digital timing inaccuracy.

If we look at the "raw" frequency graphs, we see that the major variation is at the end when I press the STOP button and the iPad is picking up the "click". Otherwise, other than the Logitech Boom and the i7 computer connected to the ASUS Essence One with very low levels of frequency undulation (I've seen this with the Essence One before with the USB interface but not with SPDIF inputs), the rest of the plots are flat lines. I am impressed by the iPad and PlatterSpeed app for being able to pick up tiny <1Hz variations.

As for the numerical analysis... Frequency fluctuation results are essentially perfect across the board and better than any turntable set-up; this includes the inexpensive Sony all-in-one CD player. The small deviations are for the most part just the bits of ambient noise or that "click" at the end being detected.

Is any of this surprising? Of course not. It doesn't negate the fact that a good turntable system can sound very good, but is a reminder of the technical limitation of a physically spinning turntable and of human hearing (ie. a non-specialized "instrument" like the iPad can pick up imperfections easily, more so than the threshold of hearing that would interfere with enjoyment of music). In fact, we might even hypothesize that a small amount of wow and flutter using a turntable adds to the "texture" of the sound, making it less "digital" sounding perhaps.

No matter how one views it, these results are a reminder for those who aspire for "high fidelity" as synonymous with "high accuracy" that digital is clearly superior (at least in the time domain as per this discussion). I was frankly surprised how well the little Sony "lo-fi" fared, actually!


Well, it was a blast zip-lining and white water rafting over the Labour Day long weekend! It's September so time to get back to work full swing... Hope everyone had great summer months in the northern hemisphere :-).

As the rainy and cool months approach here in Vancouver, I'm looking forward to some quality listening in the 'man cave'... Enjoy the tunes, everyone...

PS: Back to School question of the week - in 500 words or less, why would anyone want to buy the 24/96 version of Maroon 5's "V" on HDTracks for $22.98? Please provide plenty of subjective descriptions :-).