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...

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...

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...

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?