Saturday, 26 November 2016

MEASUREMENTS: On the value for ethernet "galvanic isolation"...


Ponderous. That's the adjective that comes to mind so often when I visit audiophile sites and come across yet another tweak suggestion. Over the years, there have been many such nuggets... Ideas like using a battery to power devices to make them "sound better" in supposedly very significant ways. Switching mode power supplies in general are said to be "bad". USB carries with it significant noise so we should to buy certain "filter" type devices (Audioquest Jitterbug, Uptone Regen, etc...). Server computers sounding different using the same high quality DAC when there's no DSP processing applied to the actual digital signal. OS optimization tweaks "reduces jitter" and again "sounds better"... The possibilities are endless!

On a few occasions, there are nuggets of truth in some of these ideas. For example, yes there is jitter to be found in some circumstances (small but measurable amounts like with S/PDIF and HDMI). Yes, sometimes you can detect noise from computers situated close to a DAC. Realize of course, many times the "solutions" advocated do not necessarily fix the problem. For example, I have yet to see a situation where a fancy passive piece of cable can fix jitter. And more often than not though, the subjective advocate/testifier/witness appears to magnify the purported effects to such extremes in the hopes of drumming up interest in what really should be rather insignificant issues. (Why folks would do this will be left to the reader to decipher... :-)

Which leads to today's topic... Ethernet galvanic isolation.

Saturday, 19 November 2016

Moving on to 4K: A look at the Sharp LC-75N8000U UHD "HDR" TV.


As you can see above, I made the move to a larger 75" screen 4K/UHD-TV from my 55" LG 55LW5600 purchased in 2011. Not sure if it's as appreciable in the image above, but the extra 20-inches diagonally make a huge difference in the movie watching experience from the sofa! (The camera focal length and perspective clearly makes a big difference in pictures...)

This is the Sharp LC-75N8000U. As I discussed recently, I've been looking around at 4K TV's for quite awhile. Admittedly, I just could not resist the price to give this a try at least (currently only ~US$2000 on Amazon)! With this post, let's have a look at this display and I'll throw out a few thoughts...

Wednesday, 2 November 2016

MEASUREMENTS: Crystal Cable CrystalConnect Micro 1m Interconnects... Differences vs. Generics???

Alright guys... As you know I've measured cables in the past - why audiophile magazines never seem to get around to this is anyone's guess :-). And as I summarized here, there really hasn't been evidence of a meaningful difference between various cables of all sorts.

Over the years, I have tried to measure cables which are considered "audiophile quality" when I can get my hands on them. You know, things like the Synergistic "Tesla" power cables, or these Kimber 8TC speaker cables. Note that obviously if I really wanted to, it's not like there aren't a selection of audiophile stores locally in Vancouver. Without evidence in my own subjective experience or reasonable theory that major differences are even possible, I'm obviously not going to go out of my way to test these things when there are so many other topics to learn about and explore! When I had the opportunity from a friend to hang on to these cables for awhile and test them out, well, why not? Especially since he's had these for years and they're well "broken in"! :-)

Behold, the Crystal Cable Micro; we're often reminded in reviews that Crystal Cable is based in The Netherlands (parent company International Audio Holdings which also owns Siltech):
Notice the small round "silver billets", all part of the typical Crystal Cable esthetic. New models have a more ovoid shape.

Saturday, 22 October 2016

MEASUREMENTS: HiFiBerry DAC+ Pro, PCM5122 digital filters & further thoughts on filtering...

A summary slide from this presentation slide set. Just a reminder of the general desirability of digital filters providing higher accuracy compared to analogue...
Thanks to Jim Ambras in the discussion of the measurements for the Raspberry Pi 3 & HiFiBerry DAC+ Pro for pointing me to some settings available! So in the "Wait! There's more..." department, there are some "advanced" settings available in Alsamixer for the DAC+ Pro I2S HAT board you might wish to experiment with. Let us have a look at the different digital filters built into this very affordable DAC and how it changes the sound objectively...

Friday, 14 October 2016

MUSINGS: Keeping it simple... MQA is a partially lossy CODEC.

Connoisseurs of French cuisine will know this guy...
In the last few days, I noticed my inbox containing a number of questions again about MQA... Presumably due to a combination of the last blog post with Agitater's comments and I guess some news on MQA after the recent Rocky Mountain Audio Fest 2016 where a number of companies were playing MQA and apparently allowing A/B comparisons of sorts.

I say "of sorts" above because it seems from descriptions the best comparisons were more along the lines of using the same file but with MQA decoding turned on/off "on the fly". Not an actual native 16/44 CD resolution file vs. MQA decoding in a volume controlled state using the same source mastering of course. Remember, the processing itself likely affects the sound quality (indeed, Meridian/MQA wants us to believe MQA processing will still benefit playback even without a decoder and folks testify about this as well). My little ABX test suggests small differences as well.

So, let's just keep it "simple" ("but not simpler" as per Einstein). Here's the bottom line for us consumers IMO...

Friday, 7 October 2016

An opinion about Audio & MQA by "Agitater"... (And a few words on DACs sounding similar.)




I suspect many of you hang out at the usual audio/audiophile message forum "watering holes" as I do. Among the chatter, every once awhile though, I run across something that a thoughtful poster obviously took time to compose and express such that I cannot but wish the message could be shared in a broader context beyond the individuals visiting the thread.

Last weekend, as I was reading the latest on Steve Hoffman's forum, I came across this opinion piece by "Agitater", a fellow Canadian out east in Toronto (I'm here in Vancouver on the west coast). Therefore, with permission to reproduce here, a comment from a fellow audiophile taken from a discussion on MQA (see page 12), but clearly going beyond into his views of the audiophile hobby and current state of affairs. So, in response to a comment about a recent article in The Absolute Sound and someone saying that Robert Harley (Editor-in-chief) is "one of the best in the industry", Agitater had this to add...

Sunday, 2 October 2016

MEASUREMENTS: Raspberry Pi 3 & HiFiBerry DAC+ Pro (Audio Streaming)


Last week in the preview, I introduced you to the Raspberry Pi 3 Model B with the HiFiBerry DAC+ Pro HAT board. You see above a picture of the boards assembled but in the "naked" state before installation in the case. As I mentioned it doesn't take much time to put this all together on the hardware side, and just a bit of tinkering with Volumio 2 was all that was needed afterwards to get the DLNA/UPnP streaming working over the wired ethernet (a little fiddling with the Volumio hotspot if you want to use WiFi - not recommended for hi-res audio). Since the software is still in development, I noticed that messing with network settings could lead to connection issues. But once it works, it has been stable.

As promised then, let us now put this device to the test and see how it performs objectively. What level of "high fidelity" does this streamer/DAC combination perform at?

Tuesday, 27 September 2016

PREVIEW / SET-UP: Raspberry Pi 3 Model B & HiFiBerry DAC+ Pro

As you know from discussions a few months ago, I'm a fan of the credit-card sized SBCs (Single Board Computers). I've already spent time discussing the inexpensive but powerful ODROID-C2 and the setup of this computer as a streamer to my TEAC UD-501 USB DAC using Volumio 2 including the excellent measurements one can get with this combination.

Today, let's talk about this very affordable combination:
Pi 3 Model B (left), HiFiBerry DAC+ Pro (right) boards.
What you see above are 3 items:
- Raspberry Pi 3 Model B - SBC computer, <US$40
- HiFiBerry DAC+ Pro - DAC "HAT" (Hardware Attached on Top) <US$60
- Inexpensive Raspberry Pi case with allowance for the HAT - ~US$10 - red to remind me I have a Raspberry in there :-) - here's a black version

Basically, we have here the hardware for a high-resolution audio streamer with integrated DAC for around the US$110 price point before taxes and shipping.

Assembled:

Tuesday, 20 September 2016

MUSINGS: 4K UHD TV, HFR, 3D, HDR, etc... Thoughts on video technology and the consumer.


As you saw a couple weeks back, when in China, I visited a number of electronics stores, especially the "big box" places in Beijing and Guangzhou. Many of these stores had on display a whole floor of 4K TVs made by all kinds of brands (many local China brands like TCL, Hisense, Skyworth, Changhong as well as the usual Samsung, LG, Sharp, Sony, etc...) and one could easily walk around and compare image quality. Of course, this is ultimately a limited comparison because the TVs are all displaying the manufacturer default settings and this usually means extremely bright, color saturated, extreme sharpness, and max'ed out contrast settings playing typically pristine demo videos so as to catch the consumer's gaze.

Even though this is primarily an audio blog, I see no need to confine ourselves to just one sensory modality... I've been wanting to upgrade to a 4K TV for awhile, certainly since my 4K computer monitor upgrade early last year. For today, I thought it would be good to think about the world of TVs and where the home visual technologies are leading us. Let's talk about some of the technology around visual quality and the parameters we should be keeping in mind, and perhaps even consider the future and what's down the pipeline. Perhaps most importantly, I like to think as a consumer in the big picture and even speculate a little bit about what might happen down the road.