Saturday, 12 August 2017

MUSINGS: The 3 Main Home Computers 2017 (Workstation, Server, Gaming) & Thoughts on Gaming Consoles (like the upcoming Xbox One X)...

In the heat of summer, it is nice to get some time off to fix up around the house and do something that I typically take no pleasure in - rebuilding computers and reinstalling the OS & software! It requires a level of "Zen and the Art of Computer Maintenance" that I can only muster up every few years :-).

If you're like me, at home, you might have a little cadre of computers for work and personal purposes. As painful as it is, every few years, I'll update the OS, maybe tweak the hardware here and there (everything from cleaning up cables, vacuuming out dust, updating motherboard firmware and drivers, and the occasional refreshing of the heatsink compound). Updating a less "mission critical" machine like a HTPC or game machine (such as previously discussed) is not a big deal because in my view, that won't affect the others. However when I update the powerful main Workstation, I try to reuse the parts for some of my "lesser" machines; can't let perfectly good high speed CPU, RAM, and motherboard go to waste.

Saturday, 5 August 2017


SMSL A6 Integrated Amp - playing through USB 24/352.8kHz signal. Notice the matte/satin finish of the aluminum case. Probably need to wipe it down once awhile if dusty.
As I mentioned last week with the initial review of the SMSL A6 integrated amp, this is a versatile device. It features an AK4452 DAC first released in 2015 which though not "top of the line", does perform very well with a potential 115dB SNR and is part of the "Velvet Sound Architecture" range of "Premium" DACs. For those keeping track, currently, the flagship DAC from AKM is the AK4497, capable of 5-channels and rated at 128dB SNR; they call this series the "Verita" which competes with the best of the ESS DACs like the ES9038Pro previously discussed in the Oppo Sonica DAC measurements and review. By the way, another claim to fame of the AK4497 is that it has a "volume bypass" mode which allows the DSD data to bypass the internal delta-sigma modulator; a more direct processing path... As usual with new features in otherwise mature technologies, whether this is audibly better is probably up for debate.

Today, what I wanted to test out with the SMSL A6 are the RCA and headphone outputs from this device. As usual, along the way we'll have a peek at jitter results, the antialiasing filter being used, and check out the various inputs - USB compared to the S/PDIF variants of TosLink and coaxial.

Saturday, 29 July 2017

REVIEW: SMSL A6 integrated amplifier - Part I: Overview and Subjective Listening (and briefly about USB cables)

SMSL A6 at home in my living room system with Tannoy Mercury Mx2 speakers. Doug MacLeod's Break The Chain (2017, Reference Recordings 24/176.4 downsampled to 88.2kHz, DR16) playing over Logitech Media Server.
For many years, my father's audio system consisted of various CD players, a Sony turntable and vintage pre-amplifiers. This then fed a tube pre-amp which then sent the signal to either a tube-based Onyx SP3 Melody amplifier or vintage solid state Pioneer amplifier to feed his Klipsch Forte speakers which have been cleaned and refurbished with new crossover parts over the years.

In the last 5 years, I've supplemented his system with various DACs for the CD player, and most recently got him a streaming connection with my Logitech Media Server based out of my home server using a Logitech/Squeezebox Touch.

This set-up sounds very good. The classic Klipsch speakers really do throw up a fantastic soundstage, have quite a smooth sonic signature (though a little mellow for my taste), is extremely sensitive, thus easily powered by low-wattage amps.

He has gradually transitioned to almost exclusively digital streaming, finding the convenience indispensable compared to spinning disks (whether of the polycarbonate or vinyl variety). As much as the tube and large integrated amps sound great, over time some of those components have needed maintenance and I figured it would be nice for him to try out something much simpler than manually turning on/off multiple devices every time he wants to hear good sounding audio. Thus, the purchase of the SMSL A6 integrated DAC/amp.

Saturday, 22 July 2017

MEASUREMENTS: The AudioQuest Dragonfly Black MQA filter set...

Good movie from the 90's!

A few weeks ago I posted on the Dragonfly Black and the MQA filter impulse responses. I noted that based on Måns Rullgård's work, although there are potentially 32 filters available when "Rendering" with upsampling to 192+kHz, I only showed 0-8 in that previous post.

Well, using the same kind of impulse response diagram previously (captured using my Focusrite Forte 24/192 ADC), here's the AudioQuest Dragonfly Black "full monty" of impulses...

Saturday, 15 July 2017

INTERNET BLIND TEST: MQA Core Decoding vs. Standard Hi-Res Audio


Well my friends, the time has come... Yes, it's another Internet Blind Test!

As a "more objective" hobbyist blog, within these pages I try to demonstrate facts, figures, and opinions as best I can with the hopes that it educates the typical "audiophile" out there who loves music and wants to at the same time understand the hardware and technologies used in the world of high-fidelity. I do this for fun with the hopes that in time, as a group we can be "more rational", each of us better able to adjudicate what makes sense, what works, and what ultimately has either very little worth or should even be considered worthless "voodoo".

Over the last few years, as you've no doubt noticed, a number of my posts have been looking at MQA and the claims made. I'm not going to rehash much of that here (feel free to start on this page and check out the links at the bottom accumulated over time). As we've come closer to understanding details like the filters used and how the "Rendering" works, there is one very important piece that remains rather nebulous.

This last piece has to do with claims of time domain "de-blurring". The idea that some kind of DSP has been used to affect the sound quality, ultimately "improving the analogue-to-analogue performance" from the studio to one's own DAC output (ostensibly using various techniques including measuring and aligning impulse responses of the devices used in production and playback). How this works is of course proprietary and hidden in the encoding system which we as end-users have no access to.

Saturday, 8 July 2017

MEASUREMENTS: MQA Filters on Mytek Brooklyn & Thoughts on USB Doohickeys

Hey folks... It's summer and I'm in and out of town doing a bit of R&R mixed with the day job.

I sent my friend with the Mytek Brooklyn and Fireface ADC a package of the MQA "Render" tagged files for testing. As you can see above, that's what the MQA filters look like with the Mytek Brooklyn serving as "Renderer" for the impulse responses. If you look at the top row, we see that the Brooklyn's standard digital filter at 24/96 is the same as what MQA uses for playing back 96kHz "original" unfolded PCM. This is different from the Dragonfly Black DAC presented a couple weeks back where the standard filter at 24/96 is a much sharper one and would shift to the weaker MQA filter only when it detects the MQA Render tagged data.

Saturday, 24 June 2017

MEASUREMENTS: AudioQuest Dragonfly Black 1.5 - PART 2 (On "MQA Rendering")

AudioQuest Dragonfly Black - "rendering" MQA playback. Dragonfly logo turns purplish...
For those keeping track, the story of MQA has slowly evolved over the last few years. Initially, it was supposed to be just a technology incorporated into DACs that would take an encoded file (typically 24/44 or 24/48) and almost "magically" transform this data into the "original" high resolution (equivalent to 24/192+) sound while maintaining standard PCM playback compatibility. This was the case with the first products like the Meridian Explorer 2. Over the years, it appears that concessions have been made. Software decoding rather suddenly was introduced in early 2017 with TIDAL's support for MQA; branded as "MQA Core". At around the same time, DACs were classified as either "MQA Decoders" for components that can handle these 24/44 or 24/48 files start to finish (Meridian, Mytek DACs), and "MQA Renderers" which require the computer software perform initial "unfolding" to high-res samplerates (88 or 96kHz) followed by some kind of final processing to the sound performed by the DAC presumably to allow the sound to be more "accurate" to the studio production, or "authentic" (whatever that means).

With the recent firmware upgrade to version 1.06, the Dragonfly Black DAC now belongs to this latter category of "Renderer". As far as I am aware, it is the first of these kinds of devices to be released without "Decoding" capability.

Saturday, 17 June 2017

MEASUREMENTS: Audioquest Dragonfly Black 1.5 - PART 1 (General)

Four USB mini-DAC's (back to front): Light Harmonic Geek Out V2, Audioquest Dragonfly Black, SMSL iDEA, AudioEngine D3.
As I showed a couple weeks ago, I have in my possession one of the Audioquest Dragonfly Black DACs for testing. I'm actually borrowing it from a friend so it's not going to be in my possession for long... Long enough for me to listen and run some objective testing to see what the "deal" is.

I think it's useful to show these test results on the Dragonfly because AudioQuest clearly has a healthy advertising budget and promotes it quite heavily on audiophile sites with ads in magazines as well; as such it's a bit of a "standard" even though a number of other alternatives exist. For example, a few weeks back, I showed the measurements for the SMSL iDEA which I thought performed objectively amazingly well for such a small device although I had some issues with seamless connectivity to Linux / Android. As you can see in the image above, I have tested a few others of these kinds of  DACs already including the AudioEngine D3 measured in 2014, Light Harmonic Geek Out V2 in 2015, and also the previous revision Dragonfly v1.2 in 2014 which I don't have on hand any more (it was given as a gift to a friend).

Saturday, 10 June 2017

MEASUREMENTS: Oppo Sonica DAC (ESS Sabre ES9038Pro based device)

My Raspberry Pi 3 "Touch" on top of the Oppo Sonica DAC - notice the DAC can handle up to PCM 768kHz (and DSD512 / 22.4MHz).
A few weeks ago, I published the preview of the new Oppo Sonica DAC and noted some issues I ran into with unusual jitter and digital filter measurements. Thankfully, Oppo was able to correct the issues within a week with the beta firmware and I see that the official firmware incorporating the improvements is now out - Sonica-33-0511 on the support website (May 15, 2017 date).

With it becoming official, I figure it was time for me to run and post results of objective tests on the device. This should give us a taste of both the capabilities of this Oppo Sonica DAC as well as look at what the "latest and greatest" ESS Technology ES9038Pro 8-channel DAC chipset is capable of... Although I have not seen it specified anywhere, my assumption is that the stereo configuration in this device ties 4 of the DAC channels for each of the stereo pair.

Saturday, 3 June 2017

MUSINGS / MEASUREMENTS: Thoughts on Vinyl LP Fidelity... (And thoughts on Sgt. Pepper's 50th Anniversary Remix.)

Alright... Let's not get worked up about the cartoon :-).

I know, the debate between vinyl and CD (digital) remains one of the greatest "wars" of the audio world; not that it should be a big deal IMO... As usual in most audiophile conflicts, there are many words spilled about the topic, but it is rare to see "data" or actual direct comparisons. For example, look at Wikipedia's entry for "Comparison of analog and digital recording" and we see no actual illustration to demonstrate differences.

Years ago, I wrote a little about this here (and I think it's only fair that I have a digital-preferring Batman cartoon). As you know, over the years there are all kinds of vinyl evangelists going around touting the superiority of LPs over CDs and digital overall (and vice versa although I'm not sure the digital camp is as evangelistic). Here's a nice example of all the awesomeness that is vinyl based on someone's opinion.

As I've said before, I agree that there are some great qualities about having an LP collection. So long as you have the space for the non-biodegradable collection, the beauty of the artwork is wonderful. It's comforting and collectable memorabilia. And likewise the sound can be alluring in the same romantic way. For some, the ritualization of the playback process can bring with it that sense of security and physical engagement as well.

Saturday, 27 May 2017

MEASUREMENTS: SMSL iDEA USB DAC / Headphone Amp (ESS Sabre ES9018Q2C + XMOS XU208)

In 2015, ESS revealed its latest generation of DACs at the CES show. One of the interesting new products revealed was the SABRE9018Q2C, a tiny 5mm x 5mm SoC claiming very high audio quality out of an integrated DAC/headphone amp operating with low power along with the ability to decode a wide range of sample rates.

I was contacted by ZugZugOrc on Computer Audiophile to have a look at a recently released USB DAC he wanted to buy for some measurements based on the above chipset. So we made an arrangement where he sent the package to me to have a look at and subsequently after I'm done, I would send it off to him to use :-). Thanks Zug for the opportunity!

Here's the device - the SMSL iDEA (can be found on Amazon for ~US$86 currently), a mini USB powered "stick" based on the ES9018Q2C "audiophile-quality" mobile DAC capable of accepting up to 32/768 and DSD512!

SMSL stands for  "ShuangMuSanLin" Electronics Company based in Shenzhen, China. I was sent the black one, but the device is also available in red.

Saturday, 20 May 2017

MEASUREMENTS: Raspberry Pi 3 "Touch" music streamer

The music being played is the soundtrack from Japanese anime Your Name (Kimi No Na Wa). Saw it with the family last week - great flick!
A few weeks ago when I described the building of the Raspberry Pi 3-based music streamer with touchscreen (I'll just call it "Pi Touch" in this post), I promised that I was going to publish some measurement results.

Well... Let's have a look at those results! :-)

Saturday, 13 May 2017

MUSINGS: On Being an Audiophile, Rationality, and Respectability (Thoughts on the Hardware Audiophile Hobby)

For the post today, I thought it would be interesting to take a step back from my usual measurements and various objective explorations and spend some time thinking about the "audiophile" hobby; you know - the big picture.

For some, the idea of "rational audiophilia" as suggested in the image above might sound oxymoronic. After all, anyone who spends thousands of dollars and hours upon hours of time on audio toys in an obsessional fashion is at the very least "neurotic" and somewhat irrational. One could spend his/her time working hard to make more money, spend time with family, read a good book, enjoy a play, take a vacation, go exercising... All of which depending on the situation potentially more worthwhile and healthier.

Saturday, 6 May 2017

PREVIEW: Oppo Sonica DAC (Thanks Oppo for making it right... On the rationale for technical perfection.)

Usually, I don't post many "preview" type articles, preferring to give you guys "the goods" when I've had an adequate amount of time with a device (usually at least a month or so) including measurements and such. I'll discuss why I'm posting this earlier as we go along...

Well, this is what showed up at my door last week:

That's of course the recently released Oppo Sonica DAC. A "hi-fi" USB, S/PDIF, ethernet, WiFi, Bluetooth digital player with DLNA streaming capability, part of the Oppo Sonica "family" of audio devices. The only other device with this moniker currently being the Sonica Wi-Fi Speaker, capable of 24/192 streaming. Coming later this year apparently is the larger Sonica Grand.

Let's have a peek inside the box...

Saturday, 29 April 2017

MEASUREMENTS: Windows 10 Creators Update USB Audio Class 2 Driver. (And a request of Neil Young / XStream.)


It has arrived... Finally... Microsoft's USB Audio Class 2 (UAC2) native Windows driver has been released with the recent Windows 10 Creators Update ("CU", version 1703, build 15063.138). I updated my home theater PC and when I plugged in my TEAC UD-501 DAC to the USB port (with no TEAC driver installed), Windows detected it and proceeded with the device set-up automatically.

Considering that Mac OS X and Linux have had "native" drivers for years, I guess it's about time that Microsoft finally got the job done. Remember, "UAC2" has been out since 2009 as an evolution of the "UAC1" standard from 1998.

Of course, this doesn't mean the Windows world has been deprived of high quality sound... Companies have been releasing their own drivers since the beginning.

Monday, 17 April 2017

RETRO-MEASURE: 2002 Lynx L22 PCI audio card in a ~2008 Intel Q6600 Computer. (On "computers are noisy!" for audio)

As many of you probably know, Mitch "Mitchco" Barnett is a regular contributor to the Computer Audiophile website with his articles. He's also the author of the book Accurate Sound Reproduction Using DSP (now available in paperback). A great guy who has logged many hours back in the day in the audio production world!

The cool thing is that Mitch doesn't live far from where I am and last year, we met up at the Vancouver Audio Show 2016 (which by the way appears to be running again this year June 24-25, 2017). We chatted a bit before the show about various topics both in life and audio. From those discussions, one of the questions we wondered about was this whole notion about electrically "noisy" computers and just how "bad" the inside of a typical PC is for high-fidelity computer audio. After all, these days we see all kinds of products claiming the importance of "noise isolation" from USB cards to power supply upgrades.

At the Audio Show, Mitch kindly lent me an old computer audio card he had at home in storage which he was no longer using (in part because he's up to date with his computers and no longer runs a machine with PCI slots :-). Here it is:

Behold, the Lynx L22 24/192-capable PCI "digital audio interface" designed circa 2002. Back in the day, this package had an MSRP of US$749. It filters the power supply, is said to have very clean ground planes, and utilizes high quality components (here's a review from 2003). At a time when probably many of us were rockin' with Creative Soundblaster Live! type sound cards, this is something meant for home studios and maybe some DVD audio production... At 15 years now since the design of this device, we had to wonder - how does this sound card measure and sound sitting in a "noisy" old computer enclosure with components dating back to the era of conventional PCI (not PCIe) slots?

Saturday, 15 April 2017

COMPARISON: MQA "Authentication" & Sound Quality? (Mytek Brooklyn & Meridian Explorer2)

You've probably heard or read the catch phrases from MQA over the years. "Revolutionary", "TAKE ME THERE"... "To the original performance..." Or how about using phrases like "end-to-end technology"?

As I have said over the last few months, I don't like talking about MQA based on my general impression of what they're trying to do and the way they try to convey supposed "value" to the audiophile world through their advertisements and sponsored articles in the audiophile press. Nonetheless, sometimes it's just necessary to comment and more importantly to put some of the rhetoric to the test. There appears to be a remarkable schism between those who advocate and praise MQA and those who have concerns. I'm pretty sure there are many wishing that MQA would just go away instead of complicating music playback with yet another questionable variant.

Last week, when I wrote about the idea of MQA CD, I brought up the Pono experience as another example of failure in the recent history of the industry. For Pono, the failure was perhaps rather obvious for those of us who have been listening to 24-bit and >44.1kHz music for awhile, especially those of us who have ever bothered to try an A/B-test. It does not take a genius to realise that audible differences are really quite subtle (if even there in most cases of mainstream music) and that differences do not translate to "benefit". Without clear audible benefits, there really was no way that the promise of the Pono music store could ever excite the music-buying public... Certainly not in the way Neil Young portrayed it (sure, the hardware PonoPlayer is unique but with its own quirks of course).

Saturday, 8 April 2017

MEASUREMENTS: Oppo BDP-105 RCA, XLR, HDMI, and other stuff for the record (like MQA CDs?!)...

Recently, I was looking at my directory of audio measurement data and realized that I forgot to put up the measurements I had collected on the Oppo BDP-105 Blu-Ray player that I borrowed from a friend in late 2016. I believe the BDP-105 has been discontinued in anticipation of the next generation flagship. The last version of the 105 was the BDP-105D which added DarbeeVision DSP video processing. This would likely not affect the audio side which is what I explore in this article and I'll obviously leave it to the videophiles as to whether this processing is beneficial or not.

As you probably are aware, this device caused quite the stir in the audio and home theater communities back in 2013 when it was first released. For a reasonable price as a universal disk player, it was capable not only of the usual CD/DVD/(3D) Blu-Ray playback but also SACD, DVD-A, and even HDCD decoding. All with flexible digital input choices - USB, TosLink, coaxial, and HDMI. For analogue output, it has single-ended RCA (stereo and multichannel) and balanced XLR analogue (stereo only) connectors. Already in 2013, Oppo had gained a reputation as a good brand with their previous models, but I think this device really put them fully on the map for audiophiles and videophiles alike looking for a reasonably priced (~US$1200 at the time) device that neither sacrificed features nor quality.

For audiophiles, the high-resolution audio output is handled by the pair of ESS Sabre32 Reference ES9018 DAC chips inside. According to the BDP-105 Wiki for those curious: "In the BDP-105's stereo board design, the 4 pairs of DACs in the ESS9018 DAC are allocated as: 1 pair for the RCA outputs, 1 pair for the XLR outputs, and 2 pairs stacked for the headphone amplifier." The other ESS chip is used for the multichannel RCA output.

Years ago, I published some results for this player (along with a DSD followup) and showed that it is indeed a very competent high-resolution device. That was back in 2013 when I was just starting this blog. Over time, I have incorporated a few more measurement and I thought it would be fun to revisit the device. This time, with my newer ADC, have a look at the digital filter in greater detail, explore the difference between the use of RCA and balanced XLR cables, and see if digital input with the USB-B interface differs from HDMI, and the S/PDIF variants... I suspect many of us have heard the BDP-105 over the years, so this might provide a nice opportunity for objective-subjective cross-correlation.

Saturday, 1 April 2017

MUSINGS: Do we "need" those >20kHz ultrasonic frequencies for high-fidelity audio?

Recently I received this excellent question and link about ultrasonic frequencies from the Computer Audiophile site:
Hi, Archimago. Visit your blog frequently and find your posts enlightening and entertaining at times without the usual smoke and mirrors.
What caught my eye in the musings on MQA utilizing the Mytek Brooklyn DAC was the selection of a musical reference which had ultrasonic, specifically musical, content. After reading the paper by James Boyk <>, ; I have been interested in the subject of ultrasonics and their (potential) effect on the listening experience fully recognizing that these frequencies are well above the capability of human hearing. Included would be identification of recordings that have musical ultrasonic content.

Given that formats such as PCM (24/96 or higher) and DSD (2x or higher)
[Ed: remember that even DSD64 1x can go >20kHz] have the potential to capture musical content above 20kHz, I am intrigued by the possibilities. As with all HiRes formats, I understand that not only all components of the recording chain but also the reproduction chain must have frequency response greater than 20kHz to accomplish this. I do see where speakers are being offered which are spec'd to 40kHz and as high as 100kHz. There are also numerous add-on "supertweeters" being offered which have this capability as well.

IF the topic were of interest to you and worthy of your time and consideration, I for one would be most interested in your musings on the subject.

My apologies for using this Musing as a portal for my inquiry but did not know how else to contact you with the proposal.

FWIW, given the potential of the existing HiRes formats to capture the musical experience if fully realized, I too am less than interested in MQA as the latest flavor-of-the-day.

Frank Zawacki
Connecticut Audio Society

Thank you Frank for the link, interesting discussion and question. I try to do what I can to collect information and synthesize posts to provide hopefully reasonable thoughts on these matters; mixed with some measurements and personal subjective impressions as appropriate.

Saturday, 25 March 2017

HOWTO: Building and Installing the Raspberry Pi 3 "Touch" Audio Streamer.

Raspberry Pi 3 + 7" Touchscreen (left) and Squeezebox Touch (right): for the Pi device, I still had the plastic screen protector on in the picture, hence the bottom left tab...
I showed you guys this picture last time of the Raspberry Pi 3-based Streamer device with official 7" touchscreen and HiFiBerry DAC+ Pro. As you can see from the image, it's very much capable of being a "clone" of the Squeezebox Touch. Furthermore, it's highly affordable with even more hi-res audio potential such as the capability to stream bitrates beyond 96kHz (remember, the stock Touch goes up to 96kHz, enhanced to 192kHz with Triode's EDO plugin).

In this post, let's have a closer look at the device and some instructions / suggestions to build one.

Tuesday, 14 March 2017

MUSINGS: Computer Audio Part II: The Basics & Suggestions

For many readers, I'm sure what I'm about to write here is relatively "old hat" by now... However, in the spirit of "Computer Audio Demystified" last week, let's talk about this powerful way of storing, categorizing, and playing our music by exploring some aspects of the foundation of computer audio in a way I hope newcomers will find reasonably accessible. I do make some assumptions in the writing that the reader has some basic knowledge of computer usage and networking. Let's consider the "architecture" of what someone might want to build, and a few reasonable options if we were to start from scratch with full disclosure of the price to build such systems.

I can imagine that some folks might need to overcome their phobia around computers. If you're motivated, just put in some time, a little patience and don't be afraid to "play" with it. More likely than not, once one has tasted the convenience and have found one's "groove", going back to only spinning physical media will likely feel archaic after a short while :-).

First, permit me to remind everyone about the two most important determinants of sound quality in a high fidelity audio system:
1. Put thought and money into good speakers, good pre-amp/amp(s), good DAC and a good sounding room.
2. Make sure the system is acoustically quiet; ideally silent.
Point 1 is obvious. The primary factors in sound quality (ie. "fidelity" achievable) are the room, speakers, and amps in that order - these are the prime candidates for sound distortion, not your computer or DAC (and certainly not stuff like cables). And Point 2 is an obvious corollary for any equipment we put in the room since we don't want the system itself to act detrimentally - this includes noisy computers, buzzy amp transformers, ground loops through the pre-amp, etc. Remember that the purpose of computer audio is simply about storing the audio library data reliably, making available a conveniently handy user interface, and the bits are being delivered in an accurate fashion to the DAC; whether internal to the computer audio device or say an external USB DAC. There is no mystery in how to come up with a solution to achieve these goals.

Saturday, 4 March 2017

MUSINGS: Computer Audio Part I: Demystifying "Computer Audio Demystified"

It's nice to see that some of the seminars at the Rocky Mountain Audio Fest (RMAF) 2016 have been posted on YouTube. It gives all of us who may have wanted to visit a chance to review the "latest and greatest" tips and updates...

Although the RMAF is hosted by the Colorado Audio Society, remember that much of the material comes from Industry; with of course the potential for vested interests influencing the content. I think many visitors to this blog would be interested in computer audio, so let's spend some time looking at the information disseminated... For your consideration, let us explore the one presented by Steve Silberman of AudioQuest - "Computer Audio Demystified" (RMAF 2016):

Feel free to watch the full 1.5 hours. For today's segment, we'll look at a bit of reality testing vs. myth vs. mysticism. You'll notice that the comments section for this video on YouTube has been turned off. Interesting. How else to discuss the contents then than in a blog post like this, right? :-)

Saturday, 25 February 2017

MEASUREMENTS: A look & listen to Roon Bridge - Raspberry Pi 3 Streaming (HiFiBerry DAC+ Pro & USB DAC)

Last time, I talked about Roon and discussed my experience with it using the NUC as the primary installation and playback. No doubt, you are aware that many people will use inexpensive devices like the Raspberry Pi 3 to handle playback distributed around one's home... And no doubt you've also come across much hyping about more expensive, low power devices when for around $100 and a little know-how, you can get it done quickly, easily and sounding great.

First, I just wanted to practically lay out a simple way to install Roon Bridge on the Pi 3 that worked for me and using which I will run a few tests to demonstrate the sonic output. Remember that the network protocol from the Roon "Core" (my Windows computer) to the Roon "Bridge" (Pi 3) is what's called RAAT (Roon Advanced Audio Transport). It's a protocol with a number of benefits as highlighted in the link.

Saturday, 18 February 2017

MEASUREMENTS: Roon 1.2 (with Intel NUC 6i5SYH)

NOTE: I know that just a couple weeks ago, version 1.3 of Roon has been released and I'll perhaps look into that a bit later once some of the initial bugs are stamped out and the system matures a little. Clearly 1.3 has a few new interesting features but the basic bit-perfect playback function I trust would be the same which is what I'm aiming at exploring in this article.

Over the last few years, I have already gradually made my way across the different audio ecosystems that most audiophiles find themselves interested in. Starting with the venerable Squeezebox / Logitech Music Server system (eg. Touch, Transporter), to standard Windows PC and Mac OS X playback, to questionable software (like JPLAY and the JPLAY update), to even just as questionable OS tweaks (eg. Fidelizer), to more recently looking at DLNA streaming using low power devices like the Raspberry Pi 3 and ODROID-C2.

For today and the next few weeks (let's see how this goes), let's spend some time on Roon, another computer audio system much lauded in the audiophile press and see if we can make a few measurements and comment on some observations and thoughts...

Saturday, 11 February 2017

MUSINGS: Discussion on the MQA filter (and filters in general)... [Update: Including a look at the classic "Apodizing" filter.]

Here's an interesting comment from the post last week...

Excellent article but I have one query. On Sound on Sound they say "MQA claim that the total impulse-response duration is reduced to about 50µs (from around 500µs for a standard 24/192 system), and that the leading-edge uncertainty of transients comes down to just 4µs (from roughly 250µs in a 24/192 system)." In that case wouldn't you need an ADC with higher resolution than the RME Fireface 802 in order to see any real differences between the Reference and Hardware MQA decode?
As I said... Dammit CBee! Now you've made me post another blog entry on MQA :-).

Saturday, 4 February 2017

COMPARISON: Hardware-Decoded MQA (using Mytek Brooklyn DAC)

As promised in my last blog post about software MQA decoding, I have been wanting to have a peek and listen to hardware decoding. Due to the proprietary nature of the MQA firmware as well as the fact that we don't have access to MQA encoder software, there is only so much we can do to explore the effect on an audio signal. Ideally, encoding a test signal and then decoding would be the best way to explore the effects and limits of how this all works...

I don't have an MQA-capable DAC myself (and honestly owning one is not high on my list of priorities), but a friend does happen to have the Mytek Brooklyn which is fully MQA-native and has the ability to decode all the way to 24/384. Furthermore, he has the use of a professional ADC of fantastic quality - the RME Fireface to make some recordings of the output from the DAC.

Image from Mytek. Obviously very capable DAC!
With the combination of the excellent DAC and ADC, we should be able to examine the output and make some comparisons. The main questions being:

1. Can we show that hardware-decoded MQA is closer to an original signal beyond the 88/96kHz decoding already done in software?

2. Can we compare the hardware decoder with the output from the software decoder? How much difference is there between the two?

Saturday, 28 January 2017

QUICKIE POST: Yes, cables matter... (for HDMI 2.0/4K/60fps/HDR...)

Well, of course cables matter! Without them there would be no sound or image! The key of course is to be wise enough to have a concept of what is needed, and how much difference the cables/wires can make.

Just a reminder, if you have not seen it yet, here is my summary of tests and thoughts on audio cables over the years if you're wondering about that.

As for today, given that time is limited this week, I just wanted to put up a "quickie" post mainly about some 4K HDMI cables I tried over the last couple months in setting up my 4K TV (a Vizio P75-C1).

Saturday, 21 January 2017

MUSINGS: On the ongoing push for high resolution audio... and the virtualization of media.

Thanks Sony for this BS diagram... Except for the most primitive non-oversampling (NOS) DAC's out there, more likely than not, DACs these days utilizing antialiasing filters of course do not output their analogue like these stair-stepped waves. Sadly, these kinds of diagrams often become the marketing material used to push hi-res! Can good outcomes result from marketing with dubious claims? (Didn't seem to help Pono, did it?)
I didn't have much time this week for any experiments/measurements. Alas, will be busy for a little while still. Which means it's a good time to put up a "MUSINGS" post based on comments and questions. Always fun to take some time to think and hopefully flesh out ideas a little more. In the post last week, I found these interesting comments worth spending some time on:

Saturday, 14 January 2017

COMPARISON: TIDAL / MQA stream & high-resolution downloads; impressions & thoughts...

As I mentioned last week, and I'm sure you've seen all over the audiophile news, TIDAL has started streaming MQA audio and has embedded a software decoder into the Windows/Mac desktop player. It will basically take a 24-bit 44kHz or 48kHz stream that's encoded by MQA and spit out an 88kHz or 96kHz data stream to send out to your DAC; whether the internal one in your laptop, or a fancy external DAC with options for "Exclusive" mode which allows changes to the appropriate samplerate (I know this works well on the PC, have not tried the Mac).

If you're not using "Exclusive" mode, you can tick "Force volume" to set it to 100% volume so the internal mixer/dither routine hopefully doesn't mess with it. "Passthrough MQA" should be ticked only if you have an MQA enabled DAC or want to purposely hear MQA undecoded (I'll say it now that this is not recommended). My assumption is that if you do have one of these MQA DACs and passthrough is on, you should either make sure "Exclusive" mode is ticked or if not, manually make sure the OS samplerate is correct (ie. 44kHz or 48kHz at 24-bit depth) and that the volume is 100% (either with "Force volume" or making sure the computer volume slider is 100%). Otherwise, it will not be "bit-perfect" and the DAC will not recognize the MQA encoding. I suspect this could be confusing for some.

Saturday, 7 January 2017

MEASUREMENTS: Raspberry Pi 3 as USB Audio Streamer (with recommended CRAAP config & TIDAL/MQA arrives)

A few weeks ago, I got this question from Josh Xaborus in my previous post on the Raspberry Pi 3 + HiFiBerry DAC+ Pro measurements:
Have you measured the USB output from the RPI3 to a USB DAC to see if it's "clean" like the ODROID?
Good question Josh, and perceptive as well. I had not posted anything on the Raspberry Pi 3 specifically, whether there was any difference to be found streaming to the same USB DAC as compared to say the ODROID-C2. Let's have a good look at this and see if we can arrive at some facts and come to some conclusions...

Sunday, 1 January 2017

MUSINGS: On the Digital Music Collection, Metadata Tagging, and Hygiene...

Happy New Year everyone! I hope the holidays went well and you're ready to take on 2017.

Today, I thought I'd spend some time talking about something extremely important and one which I'm surprised I don't hear more about looking around forums and audiophile watering holes... It's the topic of how one creates a collection of music. The difference between a collection and just plain hoarding is of course the discipline of organization involved in the collector's hobby. The collector knows what he/she has. The collector has mastery over the collection. Though responses may be variable, I believe a friend or even complete stranger would be able to appreciate the time and dedication that a collector has put into achieving this mastery as opposed to a sense of revulsion when faced with the hoarder (this is honestly the feeling I get when looking at this "collection").

Over the years, I have seen a handful of articles like this one which also introduces one to Picard, the free MusicBrainz software that will do the job in an automated fashion. If I were to start putting a new collection fresh today, I'll probably do something like this and grow from there, adding customizations, and checking accuracy along the way. However, I have been collecting CD's since the 1980's and over the years, especially after 2004, I have migrated all the "physical" music over to my music server. Through the years, although I have gone through multiple hardware servers, the data from the music collection really has not. It has been essentially rip once into a lossless format, and the CDs packed up in storage thereafter. As the years go on, I suppose like every collector, one develops a unique way to archive the albums, manage the directory structure, and a way to tag the files in a fashion that "works" for oneself.

Let's start the new year with a look at one way to manage the music collection (my idiosyncratic way :-). It has served me well and maybe some of what I do will resonate with you as well...