MEASUREMENTS: Intel NUC [6i5SYH] (and Audio)

Packaged contents of the NUC - mounting screw, universal power jack attachments in the bubble wrap, metal VESA mount plate under the power supply, basic instructions.

Like most of my computer upgrades lately, it's not because I need the speed, or expect much power saving, or necessarily to silence a noisy machine... Speed, efficiency, and quietness have been achieved to the level I'm satisfied with for years now! No... It's because I wanted to upgrade my work computer to something that handles 4K resolution :-). As discussed here and here, over the last year, I've been transitioning to what I think is going to be the target resolution for the foreseeable future (in a way very much like how audio CD resolution has been completely fine for decades). Beyond 4K, the reasons for even higher resolutions drop off exponentially based on the physical limitations of vision. (Of course, beyond spatial resolution, HDR color range and contrast ratios are important and those are catching up nicely.)

A few months ago, I decided to upgrade an aging 24" Dell monitor with a new ASUS PB287Q - quite a nice reasonably priced 28" 4K unit. (If I were to buy today, I would take a good look at the LG 27UD88 or consider the 21:9 LG 34UC98.) Alas, for the last while, I've been running the monitor at 1200p resolution with the current work computer. Though the upscaling doesn't look bad, it's noticeably compromised compared to actual native resolution of course.

As a simple way to upgrade instead of buying all the parts and assembling a new computer, I decided to go with the current generation Skylake NUC "Next Unit of Computing" - the Intel NUC6i5SYH which houses the Core i5-6260U processor with the Iris Graphics 540 integrated GPU. This NUC case allows for a 2.5" SSD/HD and M.2 SSD. If you want an even smaller, flatter unit, consider the similarly-priced NUC6i5SYK, the same innards but with a smaller case removing the 2.5" bay so the internal SSD will have to be an M.2 card.

A Response RE: MQA, "blocking" of Meridian's responses, and A/B Tests...

Just a quick note (remember... I'm on summer holiday and all!). Someone passed along to me this article from Hi-Fi+. It's an interview with Bob Stuart and Morten Lindberg (2L) apparently conducted in May. I'm bringing this up because the first Q&A is about "detractors" and there's this curious response:

BS: We’ve had some detractors, but frankly where we sit, we’ve been actually rather pleased how few. We’ve come in with an inconvenient truth – digital audio hasn’t been done right – so we thought the community might attack us. And one person put up a long blog about MQA that was just inaccurate, but blocked all our replies. As we say in England, “That’s not cricket!”

Now I don't know if this is definitely in reference to this blog and specifically to posts here and here but over the last few months I have heard this claimed... That somehow Meridian tried to post a response but the message was "blocked" (presumably by me) and that presumably the message would have contained corrections and answers to the issues raised.

MEASUREMENTS: Focusrite Forte USB Audio Interface (ADC & DAC) + Summer Musings

Product shot from here.

A few weeks back, I mentioned that I grabbed one of these Focusrite Forte USB2 audio interface units for some home recording projects I wanted to do. Beyond using it as a measurement device, my old Creative E-MU 0404USB was being used for some of these recordings and I figured it was time to upgrade to something new since a couple of the analogue pots were getting a little scratchy and I figured an all-digital device like this would allow me to more accurately adjust the volume on the microphone pre-amps (indeed it has worked out very well!).

A size comparison.

MUSINGS: Digital Interpolation Filters and Ringing (plus other Nyquist discussions and "proof" of High-Resolution Audio audibility)

A couple weeks ago, Whackamus posed this interesting comment and question which I thought would be a good topic to discuss and explore in greater detail and with some examples/samples:

"I've been reading your blog for years. Or for almost four years, at any rate. I have to thank you for doing what you do. I've likewise always wanted to ask you a question, too, but I don't know how the bleep to to contact you. In any case, since I've been fretting over it afresh, I thought I'd just post it here. If you ever do decide to get to/address it, that'd be great. If not -- hey, no sweat. :)

In any case, I read the following (tonight) on the Stereophile forums:

"I personally think that MQA has some noble goals, in terms of getting as close to the original master as possible, but I think that is far less important than the elimination of the damaging pre-ringing distortion. This has been the bane of digital playback for 30 years, and over-sampling and various filter techniques have tried to deal with it, with limited success."

I won't say that I've never heard ringing -- because I probably have -- but I will say that I've never explicitly said: "Aha! Eureka! Thar be ringing!" Because -- outside of maybe a blurring during transients? -- I have no idea what it sounds like. But my question is less about MY having heard ringing than about the AUDIBILITY of ringing -- pre, post, or otherwise. In a quality DAC (which I've got to assume most of the folks posting on Stereophile.com have access to), how audible are ringing effects? Or, rather, how COMMON are they? I kind of imagine that the Meitners, Lavrys, Levinsons, Stuarts, etc. of the audio world take great care to minimize (pre-/post-)ringing effects and to eliminate ringing in the audible realm. I likewise imagine that both such things are doable, inasmuch as most of us have been enjoying digital audio for decades now. But the Stereophile poster makes it seem as if ringing is the apodeictic bane of digital audio. What am I missing?"

The Vancouver Audio Show 2016 (June 25): Pictorial & Comments (the MQA Demo, and Show Musings)

As I mentioned a few weeks back, the folks at the Chester Group have put on the Vancouver Audio Show again this year at the Hilton Metrotown (in Burnaby). I must admit, it's not the ideal weekend for an audio show. Summer holidays starting, weather getting better, this is also the opening weekend for the Vancouver International Jazz Festival... I guess the "music lovers" can enjoy the great outdoors while "audiophiles" can hang out indoors checking out the gear :-). Last year, they had it in May which probably makes more sense.

I spent most of Saturday at the show. It was a blast meeting up with Mitch (aka Mitchco on Computer Audiophile, recent eBook on the use of DSP in the listening environment) and wandering the hallways through the various showrooms with my buddy Phil and catching up with my dad who was there as well. As I mentioned before, I think Vancouver has the luxury of a decent selection of "high end audio" stores already but it's certainly nice to be able to come to one place to check out the gear and listen to what's new.

MEASUREMENTS: Gigabyte GA-Z170X-Gaming 7 (Creative Recon3Di) - Motherboard DAC / Audio Output

A number of months back, I rebuilt my HTPC set-up to run the new Skylake i5 processor. I thought it might be interesting to measure the motherboard audio output of the Gigabyte GA-Z170X-Gaming 7 to have a peek at what a typical modern "gaming" motherboard's audio output performs like. Here's the back panel and a picture of the MoBo:

Rear panel - note the blue TosLink cable, beside it the analogue phono plug for stereo out...

As I described in that article, the Gigabyte motherboard forms the foundation for the the new build. Technologies built into the new "consumer performance" Intel Z170 chipset includes compatibility with the new Skylake processors of course, more PCI-E lanes, up to 10 USB3.0 ports, up to 3 M.2 interfaces for SSD storage, etc. As I mentioned previously, this motherboard also has HDMI 2.0 + HDCP 2.2 capability (firmware upgrade available now and ready to go), plus there's Thunderbolt 3 out from that little USB 3.1-Type C port - very cool.

If you look at the Gigabyte literature on the website, you see that they're also hyping up the audio output somewhat. Upgradable opamp, Creative Sound Core3D quad-core processor (for 3D positional sound), high-end capacitors (Nichicon MUSE MW "Acoustic Series"). After installation, the audio device is identified as the "Sound Blaster Recon3Di" [presumably the 'i' indicates "integrated"].

How good is the analogue output from a modern computer motherboard like this?

MISCELLANY: Vancouver Audio Show, Focusrite Forte Ahead, HEVC, Surround Audio CODECs...

Hey there guys, life and work is busy so I thought the post this week would be to cover a few miscellaneous thoughts from the last few weeks.

First, as you can see in the picture above, it's coming again this year! I guess the Vancouver Audio Show went well enough last year that we're going to see a repeat performance with the Show this year... Nice. I remember that there was no mention of the Show at the usual audiophile websites so I figure I'd let everyone know it's coming. Thankfully here in Vancouver we do have a few audiophile stores with good showrooms. Plus with the city (as well as much of the West Coast of North America) being a place where rich Asian investors like to park their cash (just look at the housing market!), it's a nice place to show off the goods... Of course, it also doesn't hurt given the relative strength of the US dollar to attract a few Americans up from nearby Seattle.

MUSINGS / ANALYSIS: Is there any value to 176.4 and 192kHz Hi-Res audio files? A practical evaluation...

Check out this article from 1998 written by the founder of Earthworks, David E. Blackmer (1927-2002).
 
Although I believe some of the contents in the article above are debatable, in the years since 1998, high-resolution, high samplerate audio has of course become common-day reality for audiophiles. As I expressed years ago, I do like the 2xCD samplerates like 88 and 96kHz. But as a result of realizing that 176.4 and 192kHz songs were not being streamed properly with my Logitech Media Server with BrutefirDRC set-up described a few months back, I started asking myself, what is it we would be missing if these albums were downsampled to 88.2 and 96kHz?

Put another way, we could ask "Is there something musical about the highest octave in these 4x samplerate files?" This highest octave for 176.4kHz files would be audio containing 44kHz to 88kHz, and in 192kHz files from 48kHz to 96kHz.

Updated Room MEASUREMENTS & MUSINGS on Importance of Sonic "Accuracy" and the Audiophile.

Chapter I: Another Round of Room Measurements...

Recently, I acquired some more LP's, got a few more IKEA Kallax storage units for said LP's and put up some art as well. Here are front and rear shots of the sound room the other day...

With the physical changes and reviewing my post from last year regarding the use of (((acourate))) along with suggestions made by Dr. Uli Brueggemann and Mitch Barnett (aka Mitchco), I decided that it was time to re-do the room measurements and see if I can incorporate the important suggestions - 48kHz sampling rate for the measurements, sweep range of 10-24kHz, and incorporation of the subsonic filtering at 15Hz. If you're wondering, the dimensions of the room are ~20' x 15' x 8' with a slight frontal tapering as shown; not a huge room by any means and not ideal dimensions but at least it's not squarish/cubish (here's a study on room dimensions and acoustics). It's in the basement of my house, built as a family media room with extra thick walls to reduce sound leakage when the kids are asleep at night (I pretty well can run the sub at reference levels with kids asleep upstairs at night so long as I close the door to the basement). The main speakers - Paradigm Signature S8v3's - are 7.5' apart up front, and the sweet spot is approximately 9' from the speakers arranged like an isosceles triangle. I make sure there is decent amount of space between the couch and the rear LP storage (>3'). [As you can see, I have the ~15-year old rear full-range Paradigm Studio 80v3's back there.]

MEASUREMENTS: ODROID-C2 with Volumio 2, and USB digital music streaming.

ODROID-C2 & unused "Fujifilm" 5V 1.0A wallwart ready for testing...

For those following along, you're recall back in March, I purchased a Hardkernel ODROID-C2 Linux-based credit-card sized single-board computer; the hardware described in my preview. I loaded up and customized the machine with Volumio 2 (RC1) a couple weeks back. And now as promised, I'll be showing some measurements using this machine with my TEAC UD-501 DAC. (Note that there has been a new Volumio image update since my last post. The current version is "VolumioRC1-fix-2016-05-03-odroidc2.zip" found here. Only fixed some boot issues apparently.)

Before I begin, let's discuss what we're trying to figure out objectively here... It has been claimed by some that the USB interface (which the ODROID will be streaming through to the DAC) can be "bad". Supposedly, it's electrically "noisy" (of course a noisy fan and spinning hard drives are also very bad). And, this is especially "bad" with computer audio because computers are electrically noisy devices and will end up polluting the output from your DAC. Hence, by this reckoning, a general-purpose computer isn't supposedly a good thing to have doing high-fidelity audio duties. Furthermore, it has been surmised by some that power supplies can be problematic. Specifically, an inexpensive switch-mode power supply (like the one in the picture above) can be noisy and again, will have deleterious effects on the sound quality.

It has been said that devices like the recently released Sonore microRendu among more fancy audio streamers like the Auralic Aries line of devices can "sound" better because they reportedly take into account the various sources of noise and supposedly have optimized hardware/software. True or not, the price of such "audiophile" grade devices can be rather substantial especially when it's a device without internal storage and acts as a digital conduit to feed a DAC.

MEASUREMENTS: Music servers possibly using UDP packets? Issues for music streaming?

Original from Obaida's Blog.

Qmax last week raised an interesting question about UDP (User Datagram Protocol) and DLNA/UPnP servers, one of the basic "Transport Layer" protocols for data transmissions used for Internet communications. We are likely very familiar with TCP (Transmission Control Protocol) in our day-to-day lives. This is the transport protocol that carries data off our NAS drives, transmits the web pages we read, and ensures integrity of our E-mail data...

What we might not be as familiar with is this other UDP protocol of communication. Whereas TCP is "connection-oriented" and "unicast" sending data between a server and a client through handshaking, UDP is a "connectionless" system where data is "streamed" across the network with potentially multiple destination addresses ("multicast") but without a need for bidirectional communications to address re-transmission in the event of errors detected in the stream. UDP is typically used in broadcast streams like Internet radio, streaming video, VOIP telephony, and multiplayer video gaming because the occasional data error is acceptable and doesn't require re-transmission. Or in the situation with video games, it's all happening in real-time and it's actually preferable to drop a packet here and there than waste time re-transmitting and potentially causing a deterioration in the action. Another use for UDP is with DNS service using small packets. It's faster, and uses less data bandwidth across the worldwide network overall.

SET-UP: Low Power Linux Audio Player (ODROID-C2 & Volumio 2)

As you know from a few weeks back, I got myself one of these little single-board computers (SBC) - the Hardkernel ODROID-C2 - and posted a PREVIEW on it. As described in that article, I had flashed a copy of Volumio 2 "Release Candidate" (0.861RC1) to my SDHC card and have been streaming music to my TEAC UD-501 DAC in the music room for the last while.

Originally, I was going to publish both the contents in this post as well as measurements but it quickly became obvious that this was going to be too unwieldy (plus the day job got very busy)! As such, let me talk about the basics of the setup here today along with a few changes you might want to try if you're streaming from one of these Linux-based network machines. Then later, we'll get to the measurements...

Note that although I'll obviously be specifically addressing the ODROID-C2 I have here, the software is portable and at present, the good folks at Volumio have software images for many low-power computers including: Raspberry Pi, Beaglebone Black, Cubox, ODROID-C1+, etc... Just check their site to see if your machine is supported with a ready-to-use OS/app image. I've been informed that RuneAudio will also have ODROID-C2 support ahead (maybe as early as this weekend), so keep an eye on that one as well!

RETRO-MEASURE: 1994 Sony MDP-750 LaserDisc / CD Player [and further thoughts on the importance of objectivity]

Okay everyone... For this week, let's go old skool! Feast your eyes on this baby:

Notice the microphone input to the right - karaoke, of course...

That, friends, is the Sony MDP-750, a "vintage" LaserDisc (LD) player manufactured in February 1994 "Made in Japan" according to the label on the back. My dad bought this unit when I was still in university.

In 1994, S. Africa held interracial elections and Mandela won. The IRA declared a cease-fire in Northern Ireland. Kurt Cobain committed suicide. ER and Friends debuts on TV. Doom became a hit videogame launching many future FPS's. W3C (World Wide Web Consortium) was founded. Netscape was founded. Yahoo was launched. The Pentium was found to have some flaws in math calculations! Of course, who can forget? O.J. Simpson gets arrested for murder charges after driving around L.A. in his white Bronco. My, how time flies!

Although my family had owned a couple other CD players before this device, all the previous optical media machines have since died. This machine is built like a tank (weighing in at >21lbs) and still plays LaserDiscs like a champ! I opened it up to check on the gears and cleaned up some dust accumulated over the years.

PREVIEW: ODROID-C2 Single-Board Computer... [And an obligatory MQA addendum.]

Over the last year, every once awhile someone will come and ask me when I was going to try out a Raspberry Pi as a streaming replacement for my Squeezebox systems... Certainly I've been looking around and while I was relaxing in Puerto Vallarta a few weeks back, I decided to leisurely check online the varieties of these low-cost single-board computers (SBCs). Here's a pretty good list of recent SBCs on the market to get a feel of what's out there in early 2016.

Without a doubt, the Raspberry Pi computers are the current reigning champions in popularity. They announced 5 million units sold back in early 2015. The recently released Raspberry Pi 3 looks excellent. Plenty of support, reasonably fast quad-core Broadcom BCM2837 64-bit ARMv8 1.2GHz, decent but not impressive 1GB RAM, OK 10/100Mbps ethernet, and convenient wireless 802.11n WiFi with Bluetooth 4.1. The list price should only be about US$35 for one of these but due to worldwide shortage, there's a bit of a markup currently (very common supply-demand issue of course).

But looking around, another little computer caught my attention - the US$40 ODROID-C2 from Hardkernel, a South Korean company. This was just released in March 2016. I was able to get it here in Canada from Diigiit Robotics but I see that they're now out of stock and like the Pi 3, prices have become elevated. Here's the block diagram for the C2:

All technical details including schematics can be found here.

As you can see, it's a reasonably powerful little unit which easily can outrace the Pi 3 computationally (some benchmarks here compared to Pi 3). Quad-core Amlogic S905 CPU with 64-bit Cortex-A53's running at 2GHz, 2GB of DDR3 RAM, Gigabit ethernet, and a video subsystem capable of HDMI 2.0 4K/60fps output and hardware decoding for H.265 (750MHz Mali-450 "pentacore" GPU). Unlike the Pi 3, this unit does not have built-in wireless communications. Micro-SD card (supports UHS-1 speed) can be used or faster e.MMC 5.0 (400MB/s interface) module for flash storage. There's also an IR receiver built-in for remote control of features like volume adjustment.

So I figured... Why not? Let's get one of these little guys with the goal being to run a simple Volumio streamer out of it (I think we'll be seeing RuneAudio on this device soon also). Here's what I got:

The ODROID-C2 with clear plastic case. Note how small this computer is - about the form factor of my Costco card :-). Around the same size for the Raspberry Pi...

MUSINGS: USB Audio Gremlins Exposed: Beyond 1s and 0s? - Analysis of Industry Content

Fear, Uncertainty and Doubt in digital audio...

[This article has been modified over the years with reduction in the quotes from an article that appeared back in 2016! Even though AudioStream has been dead for years, I suspect iFi really doesn't like this article. I've received a number of claims that this article has been in "violation" of some kind of terms reported to Google. To be honest, I'm not sure what's the problem since free speech does allow me to quote from published articles and ads for the sake of voicing my own commentary. --- December 2023]

Oh my... Run for the hills folks! Didn't you hear? USB is a horrible interface for audio purposes!

Hmmm... At least that's the kind of interpretation one might be tempted to consider after reading this "truthy scientific" article on AudioStream ("USB Audio Gremlins Exposed: Beyond 1s and 0s, by iFi Audio")! What can I say? Brutal! Nice example of content from Industry to instill some measure of concern among susceptible audiophiles.

Okay, let me first say that I'm not claiming that USB is perfect - nothing is... You could run into issues. But the fact really is that these days, with a decent asynchronous DAC (what decent audiophile USB DAC these days isn't asynchronous?), one should not be concerned with data errors, jitter issues, and I have yet to come across noise pollution from a computer other than atypical situations like what I demonstrated a year back.

A typical $10 USB cable made to appropriate specifications by a reputable brand is fine.

With that said, let's delve into this short "article" and consider truth and fiction (delusion?)...