Archimago's Musings

Back in 2019 I wrote the article "Why We Should Use Software Volume Control / Management" which not only addressed about intersample overs, but also floating point induced clipping which cannot be solved by having intersample headroom in the DAC. (For a quick listening test, try the files in this thread on ASR). However it seems that some people are still not happy with the proposed solutions (e.g. ReplayGain) and resort to some other methods. For example in some of the recent blog comments someone mentioned about BitShiftGain.

Here is a snippet from the BitShiftGain website:

Digital audio is like some crystalline structure: it’s fragile, brittle, and suffers tiny fractures at the tiniest alterations. There’s almost nothing you can do in digital audio that’s not going to cause some damage. But as long as you stick to 6 dB steps and rigidly control the implementation (BitShiftGain doesn’t even store the audio in a temporary variable!), you can chip away at that least significant bit, and the whole minutes-or-hours-long crystalline structure of digital bits can remain perfectly intact above it.

Preamble: In this article, I'll clearly be supportive of multichannel/Atmos music playback for audiophiles. This in no way should be seen as disparaging to those who feel that 2-channel stereo is completely adequate if not optimal for their listening! Simplicity, space considerations, availability of content, budgetary factors, perceived artistic intent, subjective preferences always play into the personal choices we make.

After 25 years of collecting multichannel content since the early days of DVD(-A) and SACD, currently about 15% of the albums on my music server are 3.0+ multichannel. With hopes that this continues to grow, of course!

Every once awhile I'll look over some of the posts I've made over the years to see if there's anything substantial I might revise or provide an addendum for. Most of the time, it's just for historical review to consider my thoughts back then, but sometimes, I'm encouraged to see how nicely things have changed over the ensuing years. Such has been the case for multichannel audio, so I thought I'd make this post as a review and pointer to the topic of multichannel music as an audiophile.

The first time I wrote a post titled "multichannel and the audiophile" was back in 2019, also during the summer - "SUMMER MUSINGS: Multichannel and the audiophile. MCh streaming with a TV Box. And Thoughts on the Future... "

Let's finish up with the last installment of the review/measurements for the Topping DX9 "15th Anniversary" DAC (see Part I, and Part II previously). As we have seen up to this point, it's quite a unique looking DAC and the initial PCM measurements over USB2.0 look great as a modern hi-resolution converter. In Part II I noted that there was an issue with the 176.4/192kHz frequency response that Topping was able to correct quickly with a firmware update. I'll be using the latest firmware 1.23 for the measurements here.

Let's continue then to dive in and explore the objective performance with some of the other main features for this DAC.

Continuing with the discussion in Part I, let's proceed with Part II of our look at the Topping DX9 "15th Anniversary" DAC as we wade into some of the technical capabilities and performance of this device.

As I discussed the other week, my belief is that for relatively "simple" devices like DACs where what we want is as-accurate-as-possible conversion of the audio data into the analog voltages, measurements are really all we need to characterize the accuracy, the transparency of the device using modern tests and instruments that are capable of capturing details beyond the ability of human hearing. The capability for any device to achieve transparency of course does not guarantee that we'll be able to enjoy the sound or the music which are determined by individual subjective psychological factors.

With that, let's jump into some PCM measurements of this Topping flagship product.

As many audiophiles will remember, the well-known DAC chip maker Asahi Kasei Microdevices (AKM) suffered a massive fire at their factory back on October 20, 2020 in Miyazaki Prefecture, Japan. This resulted in a shortage of their chips for awhile until they rebuilt the plant and started offering devices again by the end of 2021.

In June 2021, AKM issued a "last time buy" notification for final stock of a number of their products. This included their top-of-the-line DAC chip, the AKM AK4499EQ which was initially released in January 2019 and had made its way into a number of devices over the ensuing couple of years. By later 2021, some devices like the HiFi Rose RS150 had to transition to ESS. With 4 channels, a published THD+N of -124dB (mono mode), 137dB SNR in stereo (140dB mono), DSD "direct" (volume bypass), this chip remains a formidable converter even in 2025 with newer generations of AKM and ESS chip DACs. While audiophiles and manufacturers like to talk about discreet DACs like R2R stuff or custom "Ring" DACs, or DSD-processing DACs (like Meitner products or Playback Designs), while I'm sure they sound great, there is no evidence that these are capable of achieving better objective resolution than state-of-the-art converter chips from semiconductor companies with significant R&D resources.

For comparison, based on company specs, the current premium DAC chips are ESS's ES9039PRO rated at -122dB THD+N mono, and 140dB SNR mono. And AKM's current flagship, the 2-channel AK4499EX DAC released in 2021 listed as THD+N -124dB and SNR 135dB stereo (138dB mono). The AK4499EQ as a 4-channel DAC is a much more complicated chip than 2 AK4499EX's because it also incorporates the sigma-delta modulator internally while the AK4499EX needs to be fed 7-bit modulator data at 5.64/11.29MHz from a separate source like the AK4191EQ ΔΣ Modulator!

So, basically, as a single chip, the discontinued AK4499EQ after only about 1.5 years in production, remains the highest performing device among its peers after all these years; on paper at least.

And that's why I bought one of these for my system - the Topping DX9 "15th Anniversary" Limited Edition DAC & headphone amplifier (US1299,ドル CAD1900ドル, depending on tariffs you might do better ordering from China through AliExpress):

Today's blog post was inspired by Mister MB in a comment he made on the post last week (about GR-Research, and the hype around passive crossover components):

Hey Arch,

Slightly unrelated, but I thought you'd be interested in this recent video about CDs vs Streaming by Guido of Anadialog:

https://www.youtube.com/watch?v=pY8PeMpT2DE

What do you think? ...

Thanks for the link MB. I've come across the ANA[DIA]LOG YouTube channel but admittedly haven't spent much time watching the contents. I certainly appreciate the host, Guido's, passion and energy! I see the content caters more to physical music media, especially tapes and LPs. As you probably know, for me, subjective preferences aside, analog media represent lower-resolution sound; no offence to vinyl/tape lovers, it's just a statement of fact (especially with LP/vinyl) given the much higher resolution capabilities of modern digital ADC and DACs, achieved with less hassle.

Good to hear about the interest around CDs these days. I guess what's old eventually becomes new (maybe even trendy) again at some point after a couple of generations! Although I have a feeling Edison's wax cylinders might have a tougher time staging a comeback. 🙂

Okay, let's continue with our exploration of the fanless HUNSN/CWWK i3-N305 computer discussed last week. This time, we'll focus on what I did here to get it running as my music end-point (for Roon), in particular creating multiple output options for multichannel, stereo crosstalk cancellation (XTC) DSP, and also for those times when I want the highest 2-channel resolution playback to the USB DAC.

Most of the time this computer will be running "headless" although it is connected to my TV and I will on occasion watch movies using Kodi. And since the machine is quite powerful (>100GFLOPS on Linpack stock), I turned down the power utilization for my purposes which in turn will keep the fanless solution cooler.

Let's get going!

Another year, another upgrade to the sound room MiniPC! 😁 Honestly, for audio streaming purposes, I could easily just use the very low power MeLE Quieter2Q as a Roon endpoint with multichannel capability discussed in 2022. As usual, "Bits Are Bits" so this upgrade is not about sound quality, just fanlessness, and higher processing speed on tap.

Recently, I saw this interesting article for an Intel i3-N305 MiniPC and thought it might be fun to try a fanless low-power but reasonably fast machine. The i3-N305 CPU consists of 8 Intel 10nm 12th Generation Efficient-cores (E-cores) with a 32 Execution Units (EU) iGPU; significantly faster than the last miniPC I reviewed which was the Beelink EQ12 with Intel N100 CPU - 4-core, 24EU.

So to give this a try, I bought the HUNSN RJ36  off Amazon, standard retail "barebones" unit since I figure I could buy the DDR5 RAM and M.2 SSD drive myself. Current price about US375ドル before RAM and SSD.

The OEM company who makes these computers is CWWK. Similar computers can be found with the Topton brand name. There's no logo or name on the box itself which to me is fine - brand names are not important to me for many tech products so long as performance, build quality and reliability (which can only be determined over time) are adequate.

In the image above, we see embedded some pictures of contemporary, expensive (>US10ドルk) digital audio devices. Each one of these are just streaming or server boxes that can take data over your network or internal storage and pass them along to a DAC with no actual conversion. Typically, these "high end" audiophile products (for example some featured here) are not asked to perform DSP, thus passing the data in a "bit-perfect" fashion. Furthermore, these expensive devices do not include an internal CD/DVD/SACD/BluRay mechanical reader. They're basically computers with hard drives or SSD storage and software to index and manage your music library. You'll typically be connecting them to your favourite external DAC most popularly through USB although proprietary interfaces (eg. Wadax's optical), ethernet, S/PDIF coax/optical, and i2S could be other options.

The other day, a family member was in need of a replacement phone so I gave them my Huawei P30 Pro which I've been using since 2019 and got a Google Pixel 8 Pro. After transferring the apps and data over, I figured I'd try to see if USB Audio Player PRO on the Pixel 8 Pro would work with the very high resolution Sabaj A20d 2022 DAC (ES9038PRO converter) which the Huawei phone previously did not. It worked, reminding me that Android USB hardware and drivers can result in different levels of USB DAC compatibility.

With the phone connected to the DAC, and given that it has been awhile since I've put together a "shootout", let's see if there's any evidence now in the 2020's of potentially audible differences between source devices playing to a very high-resolution USB DAC. Not that I have a 10ドルk streamer lying around here, but a 1000ドル phone could be different from a sub-100ドル Raspberry Pi, right? 😉

[FYI: years ago, I did a test similar to this using various mostly S/PDIF outputs connected to the same ASUS Essence One DAC.]

Let's look at some data.

Since around 2004, I've been using various computer systems for music playback, initially starting with ripped files on PCs and then quickly transitioning to server-endpoint "distributed" playback by something like 2006/2007 when I bought my first Slim Devices Squeezebox 3. I've never really looked back since, as this is IMO the superior way to manage music with a central home server repository and distributing the music around the home. It has been more than a decade since I've cared to use a CD transport other than to rip music and there's no reason why CDs would sound better anyways ("bit perfect" and all that).

Of course back in the day, especially prior to 2010, putting a computer in the sound room was likely going to be fraught with noise issues. In the 2nd decade of the 21st Century now, with much lower CPU/memory/motherboard power demands while capable of excellent speed, silent SSD drives, and small form factor MiniPCs, it's actually rather trivial these days to maintain cool and quiet, unobtrusive computers that perform well as AV "appliances". These machines will not contribute to acoustic or electrical noise pollution in listening rooms even with low ambient noise levels provided the hobbyist approaches device selection and optimization with some basic care.

Today, let's convert that little Beelink EQ12 Intel N100-based computer (discussed/reviewed last time) into something I would use as a Windows audio streamer and movie player in my media room. Let's talk about some BIOS settings, Windows set-up suggestions to consider, and computational potential.

For more than a year now, since the MeLE Quieter2Q, I've transitioned media playback away from the Raspberry Pi system in my main sound room as I've explored options in the MiniPC world. This is the result of technological progress as x86/x64 processors have become significantly more energy-efficient, available in smaller packages, with increasing processing speed, access to the huge library of PC software, and capabilities including support for multichannel HDMI audio output and 4K video decoding.

Yes, we could easily build massive "He-Man" computers these days sucking hundreds of watts to power fast CPUs and modern discrete GPUs, even as "audiophile computers", I believe these are clearly inelegant solutions for AV playback or even as a media server.

Today, let's look at a new entry - the Beelink EQ12 (currently just around US250ドル-300 depending on deals, with 8GB of DDR5 RAM, 500GB NVMe storage as tested). This machine uses the latest 12th Generation 10nm "Alder Lake" quad-core Intel N100 low-power processor running at up to 3.4GHz turbo. With this new generation, Intel has moved away from names like "Celeron" and "Pentium". While the specs say TDP of 6W for the part, in real life the computer does suck up more power.

For audiophiles thinking of using HQPlayer, these new processors feature the AVX2 instruction set; opening the doors for using the new versions of that software under Windows again should you desire. For the record, this machine was purchased through the usual retail channels.

Let's have a look today at this hardware, and evaluate the speed compared to previous reviewed machines on this blog.

Hey there gals and guys. I've been busy over the last while getting some things at work going, so this means it's time for a survey to hear from you ;-).

It's always good to know what audio lovers are doing out there and this could of course help me look at interesting topics to examine in the future. The last time I did this was back in 2019, looking at adoption of streaming services and lossy vs. lossless among the readership - much has changed since then!

These days, if we look around most homes, I think we'll see all kinds of computers used for different purposes in the rooms. I've talked about my main Workstation, the Server machine, even my Gaming rig a number of years back (much of that upgraded since). And a few months ago, we talked about the very low power fanless Celeron MeLE Quieter2Q which functions as a very stable stereo/multichannel streamer for Roon.

[BTW, there is an upgraded MeLE Quieter3Q now which is faster by ~30-40% featuring the Celeron N5105 processor for a few more dollars, but still no AVX2 if you're thinking about Windows HQPlayer as discussed here.]

Recently, I've been wanting to upgrade my 2016 Intel NUC 6i5SYH which in the last few years has been the heart of the audio measurements rig. Over time, as my measurement regimen has become more detailed, often using larger FFTs parameters, once awhile, I've started noticing that the old i5 CPU isn't keeping up with the processing needs and this shows up as glitches in the data such as when running multichannel REW "stepped sine" captures. Obviously, this will not do. ;-)

To remedy the situation, I got one of these Beelink SER4 Ryzen 7 4700U-based MiniPCs (8-core, 8-threads, currently less than US450ドル for the 16GB RAM/512GB M.2 SSD model). There is also a more expensive SER4 with faster 4800U processor (8-core, 16-threads) if you need that extra speed.

This machine was purchased from standard retail channels; this review was not sponsored in any way.

I like a good challenge ;-). A few weeks ago, in my post on the E1DA Cosmos APU, in the comments, MG discussed achieving THD -155dB on the Victor's Oscillator! In my original post, I showed a picture of -141dB. Subsequently, I then fiddled around with the set-up and achieved around -148dB.

Well, on one of my lazy afternoons, I thought I might as well give this another try. The aim - at least THD of -150dB. So I packed up some parts I needed and moved it into the quietest room (electrically and acoustically) in my house. Bits and pieces laid out on my ottoman where I place drinks on late night listening sessions. ;-)

Clearly this would have to be run off battery power to remove any mains hum. I went with my trusty RME ADI-2 Pro FS ADC, powered by a 12V/8300mAh TalentCell lithium battery pack for convenience in case I needed to fool around with input voltage settings. The E1DA Cosmos APU was powered with a 5V battery pack.

Hey folks, a few weeks ago, I mentioned that I've got the little MeLE Quieter2Q Windows 10/11 computer in my sound room these days used as a low-power (<10W) Roon streamer capable of 2.0 and 5.1 multichannel. The computer is relatively powerful for just an audio device handling Roon streams; 8GB DDR4 RAM, a 2.0+GHz turbo Celeron J4125 quad-core CPU is certainly much more than needed just to basically get data from the gigabit ethernet and shove it to USB or HDMI for playback!

It works fantastically also as a little fanless HTPC for movies with 4K video and audio bitstreaming. A tip: K-Lite Codec Pack works very well, it can even play MKV/MKA files with lossless TrueHD-Atmos like the 2019 Beatles Abbey Road BluRay rip which I know will trip up some HDMI hardware.

I mentioned in the previous article that it might be fun to consider utilizing the processing power of the little fanless box for audio. For many Roon users, one way of taking advantage of processing power is by using HQPlayer from Signalyst for high-quality upsampling with digital filtering, and possibly even PCM-to-DSD conversion. 

Over the last number of years, I've been a Roon user (lifetime membership, no I have not been subsidized in any way by the company). Although not perfect, it works well for me and I've certainly enjoyed the bountiful metadata this interface provides. The Roon software has unified control and access to my music library through Roon Core running on my Windows Server machine. In doing so, this has brought all the hardware playback systems in my home under the same "umbrella" whether it's my Workstation PC (listening to music writing these blog posts), on my phone using Bluetooth headphones while doing housework, or casually streaming Internet radio to the Chromecast Audio - Roon serves them all. The main item on my wish-list is for Roon to support streaming from the library remotely such as from the office.

For those who have read this blog over the years, you'll know that I like multichannel audio playback (discussed here, and here among elsewhere). No, I am definitely not one who thinks 2-channel is somehow "audiophile" territory and that multichannel is the domain of the "home theater guys". Audiophiles IMO should be greedy; we want it all because the love of music and the experience of great sound quality do not end the moment we go beyond 2.0 or 2.1 channel layouts! Some of the best sonic experiences I have had are with multichannel content and hardware.

As you likely know, I've been an advocate for Raspberry Pi devices, like the Pi 3B+ "Touch" and Pi 4 "Touch" builds discussed over the years. I still use these when I run my DAC tests given the convenience of the touchscreen and of course the price represents great value. However, there is a feature which still eludes the Raspberry Pi boards - I want easy multichannel Roon streaming in my main soundroom.