MEASUREMENTS: A Look At HQPlayer 3.25; Filtering, Dithering and DSD Conversion.

Over the years, no doubt many computer audio users have heard or perhaps tried using HQPlayer Desktop from Signalyst for music playback. While there is a GUI for playback as well as a sophisticated network transport architecture, it's the upsampling and PCM-to-DSD features that are the program's claim to fame. There has been a good amount of talk about the sound quality of the upsampling algorithms and some swear by the sonic differences the program makes.

While admittedly I don't follow HQPlayer chatter closely, I don't recall reading about specific settings and what they do other than opinions about the sound quality. In this way, HQPlayer has been a bit of a mystery and I know some folks have had difficulty getting it running over the years. It has certainly been on my list of items to look into. In fact, back in early 2017 when I wrote about Roon 1.2, I mentioned installing HQPlayer but never got around to actually writing about it.

Well, after all these years, and now with the requisite pieces of hardware at my disposal for a more thorough evaluation (reasonably fast CPU/GPU system, ADC capable of >192kHz, DAC capable of DSD512), it's time to have a peek "under the hood" at what it does...

MUSINGS: Computer audio mythos? A comment on The Linear Solution's DS-1 Network Streamer.

Interesting... But in physical reality impossible of course! Perhaps like many audiophile opinions? [Info on art here...]

"Your desires and true beliefs have a way of playing blind man's bluff. You must corner the inner facts." 

--- David Seabury (1885-1960)

A few weeks ago, I read this "Quick Take" review of The Linear Solution DS-1 Network Streamer device published on Computer Audiophile (now Audiophile Style) by austinpop. Wow... I was impressed by how many computer audiophile "beliefs" were strung together all in one article! A good place to start and think about the "evolution" of computer audiophilia in 2019 perhaps.

MUSINGS: Why bother with 24-bit DACs? (With thoughts on dithering, digital volume control, normalization, streaming and LUFS.)

I've heard over the years some people wondering whether there really is a point to 24-bit DACs. After all, there is little if any evidence that "hi-res" 24-bit music actually sounds any better - in fact, you might recall that way back in 2014, here on the blog we ran a blind test and the results did not show significant audible benefit among respondents. More recently last year, even with Dr. AIX's "HD-Audio Challenge", very few people were able to experience benefits to "hi-res" audio (no surprise of course!).

INTERNET BLIND TEST: Do digital audio players sound different? (Playing 16/44.1 music.)

The other day, I was surfing the usual audiophile haunting grounds and came across this poll question on the Steve Hoffman Hardware Forum started a year ago. It reads: "Do You (Think) That Different CD Players Have Their Own Sonic Signature?"

Here are the results when I looked recently. I know it was closed last year, but it looks like it might be re-opened and still running into April if you want to cast a vote:

I thought it's worth spending some time to discuss this very simple question which of course is both understandable and asked frequently among newbies and longtime audiophiles alike. It's an important, and "core" question which can still be highly contentious after all these years! As suggested by the "blind test" title, by the end of this post, I will give you dear readers an opportunity to "cast your vote" and tell me what you think with a poll of our own using test samples to try (if you dare)!

 Let's make this our winter/spring research project...

MEASUREMENTS: Oppo UDP-205 DSD Playback (DSD64-DSD512), and PCM 768kHz. Plus CES2019 coverage thoughts...

Alright guys and gals, it has been months since I completed the set of measurements of the Oppo UDP-205 last year (here, here, and here).

In early December, David M wondered how the Oppo performed as a DSD player as I had neglected to measure that.

Over the years, I have measured DSD output performance but remember that this is a little bit of a pain :-). To obtain some results for comparison with PCM in RightMark, what I typically do is take the test signals (originating in 24-bit PCM), convert to DSD using software like Weiss Saracon, and then play back the DSD file through the DAC into the ADC which of course takes that analogue output resampled back into PCM for analysis. Doing this understandably adds other variables to the measurement system which should still be minuscule. Over the years, I have looked at things like PCM-to-DSD converters (here and here) to demonstrate that the conversion programs do have an effect as one would expect with different resampling and modulation algorithms.

GUEST: Future Proofed (and didn't know it) - Adding Streaming to My Existing Hi-Fi.

Every once awhile, it's great to have a guest writer put up their thoughts on the Musings. I've always lived by the principle of "it really isn't what you got that matters, but how you make the best of it". I think Allan's post here is a nice example of that. These days, we have all kinds of products and technologies easily available at good prices, but when mixed with streaming services, sometimes one needs to do a bit of digging to get everything to work right the way one desires. One could spend countless dollars on things that might or might not really be of value. How we use what we have can take all kinds of forms and ultimately is a reflection of us taking control to satisfy our needs while reflecting understanding of how the products and services work... This Guest Post is a nice reminder of that!

Take it away, Allan...

GUEST POST

by Allan Folz

Introduction

Last spring on this humble blog I wrote a guest post reviewing the Sony HAP-S1. At the time I had a number of complaints with regard to the feature set. Indeed, I wasn't entirely sure I was going to keep it for the long-term. My biggest problem with the HAP-S1 was that I could not use it with any of my preferred Internet streaming services. The HAP-S1 has a pair of analog inputs and I bought it thinking I could use those with the headphone jack on my phone and laptop to be able to play back music streamed from the Internet. Also, while I knew when I purchased it that it didn't support Bluetooth, I had planned to get a Bluetooth to analog-out receiver that I could connect to its analog inputs. Unfortunately, after I received the unit I discovered there is a limitation in that the analog inputs can only be used to drive the HAP-S1's internal amplifier. Since I was using the line-out of the HAP-S1 to drive a pair of self-powered monitors, there was no way to get the signal from the analog inputs to the line-out. Instead, I'd have to move the monitor's input wires from the HAP-S1 to the phone or laptop each time I wanted to switch sources, which was a non-starter. (Or purchase a pre-amp, which was far more expense and space than I was interested in undertaking.)

A Look at the Oculus Rift Touch VR System! (And the Oppo UDP-20X gets a firmware upgrade for HDR10+.)

Happy 2019 everyone!!!

It looks like Archimago was a nice boy in 2018 :-). Look what Santa brought him under the Christmas tree:

The Oculus Rift + Touch VR Bundle runs very well on that Intel i7 / nVidia GTX 1080 computer I have in my sound room.

As I mentioned last time at the end of 2018, I don't use the "man cave" just for 2-channel music listening (I think instead of calling it a "sound room", I should rename it my "media technology room"). Today, I'll just share a few thoughts on this device. While this isn't the usual stuff I talk about around here, I think it's good to look outside the audio hobby regularly and consider all the things the modern media technology hobbyist can do that vie for one's attention and time! VR being one that's still IMO very much in its infancy...

MUSINGS: On this Blog, Motivations, and Recent Audiophile-Targeted Articles in the "Mainstream" Press. Holiday Edition!

Hey guys & gals, grab a coffee, maybe a hot cocoa! Winter is here, at least in the North, so settle into a comfy chair by the fireplace as we head into the last days of 2018. Let's chat.

Recently, I received this comment from Museatex which I thought was a good comment and deserved a bit more discussion as a post rather than just a response which would typically be lost in the usual chatter:

Museatex 5 December 2018 at 22:59 

"Now we add the 10-year old Energy C100 speaker pair to the receiver amp. The Energy sounds similar in tonality to the rear Paradigm Studio 80's. Perhaps not surprising since both are Canadian companies using research from the National Research Council and are not far apart in age."
I haven't had such a good laugh in a while. :)
BTW I do enjoy glancing at your measurements but I am somewhat puzzled as to why you started this blog. You invest money in new sound cards/adc and not in room treatment? $15 google chromecast audio sounds to you the same as logitech transporter so why not to spend money where you can measure a real difference such as room treatment? You room is dying for acoustic treatment while you are chasing minuscule differences in digital filters you cannot hear. Why waste money on monoblock amplifiers if it is irrelevant? I mean have you compared them to $300 receiver in properly setup double blind test? ;). Please continue on doing what you are doing as I do enjoy looking at graphs at someone's else expense, though I do not understand your motivation.

Hello Museatex, good comment and in fact, it's good to discuss the big picture and motivations once awhile. To be honest, there isn't one motivation. Perhaps back in the day when I started this blog, there was a more specific intent - which at that time was just to start an online blind test to see if audiophiles could reliably hear a difference between high bitrate MP3 versus lossless FLAC compression. But remember, this is a blog. It is by nature an "online journal" of what myself and a few contributors over the years have thought worthwhile to share.

MEASUREMENTS: Intel i7 PC and Raspberry Pi 3 B+ Audio Streamer - XLR / RCA, Noise and Jitter. Do digital transports / streamers really make a difference? Do USB cables?

This is a picture of the corner of the room where I performed the measurements for the post last week. Notice that Intel i7-3770K computer in the left corner I use for gaming? Within that box are 16GB DDR3 RAM, both a SanDisk Ultra II SSD and a recent 2TB Firecuda drive, plus a rather powerful nVidia GTX 1080 graphics processor which is what is driving the display on the 4K TV. Inside the case, it's all powered by a 6-year-old Antec 650W switching computer power supply these days. The computer is about 6 feet away from the TEAC UD-501 DAC.

Suppose I take a 16' USB cable and connected this computer to the DAC and compared the measurements with the low-power Raspberry Pi 3 B+ streamer... What do you think the result would be from the perspective of distortion and noise?

MEASUREMENTS: Raspberry Pi 3 B+ as streamer - switching power supply, battery, WiFi, touchscreen noise??? (32GB RAM, MI: Fallout and The Beatles' 2018 "White Album")

Battery-powered Raspberry Pi 3 B+ with JustBoom Digi. Bohemian Rhapsody soundtrack.

Remember that within audiophile circles, there are often all kinds of claims about noise affecting streaming devices; especially computer-based devices. I already touched on this last week when referencing the videos by Innuos. Over the years, I had addressed software playback, different OS's, lossless formats, "need" for ethernet galvanic isolation, and explored the lack of difference between machines used for playback. In a similar way this post will also explore some "received wisdom" which seem so common among mainstream industry-supported audiophile websites.

Since I had my set-up running for last week's evaluation of the JustBoom Digi, I figure I might as well do a few more tests to demonstrate for myself (and you, fellow readers) whether these beliefs hold any truth.

MEASUREMENTS: JustBoom Digi S/PDIF HAT for Raspberry Pi. (Plus "Why isn’t digital audio 'just ones and zeroes'?" anxiety...)

I mentioned a few months back in September that I updated my Raspberry Pi 3 B+ Touch device with the JustBoom Digi HAT for S/PDIF coaxial and TosLink digital audio output. Over the last few months, I've been using it more regularly for my nightly music listening.

As I noted previously, this device is essentially a 1-chip solution featuring the Cirrus/Wolfson WM8804 transceiver with jitter attenuating PLL (rated intrinsic jitter of ~50ps RMS) released in 2009. It also uses the Murata DA101JC isolation transformer for the coaxial output.

The device is rather plain otherwise as you can see. It does sound good and is capable of up to 24/192 with both coaxial and TosLink outputs. And at <US$40, it's also very affordable. Let's see how well it measures!

NOS vs. Digital Filtering DACs: Exploring filtering turned off, implications, fidelity and subjective audibility. (Recent BorderPatrol DAC chatter...)

Hmmm... Non-OverSampled waveforms - "accurate", "high fidelity"?

The waveforms above were captured with my RME ADI-2 Pro FS ADC at 384kHz. As you can see, on the left side, we see the waveform from the TEAC UD-501 DAC with the digital filter turned off (Non-OverSampling - NOS mode). In the middle, we have the TEAC's "Sharp" oversampling filter engaged. And on the right, we see the same waveforms captured from an old 16-bit Philips TDA1543 x 4 DAC with chips in parallel (supposedly improves noise level), a multi-bit NOS chip, without any oversampling.

Here's the TDA1543 x 4 DAC board. Typically fed with a 12V DC power supply.