Archimago's Musings: Terms & Conditions, Privacy Policy

Sites need to comply with General Data Protection and Regulation (GPDR) policies if there are visitors from the EU, so for transparency, here are some broad Terms and Conditions as well as Privacy Policy statements for this blog as we enter 2024.

Basically this: I trust we're here to learn, enjoy the hobby, debate sometimes, as generally anonymous participants, acting like decent persons online. The purpose here is not to sell stuff or make money even though I don't mind getting a little "tip" if folks buy stuff for example off Amazon links or if the ads work out for you. I have no interest in soliciting funding from anyone such as with Patreon and the like; my day job pays just fine.

Be mindful that public comments are public so don't say anything private unless you want it known broadly. No doubt in the days ahead there will be all kinds of bots and increasingly sophisticated autonomous agents reviewing the information and scraping the data. Consider how this might have an impact on you and the comments made.

Cookies and IP addresses are sent to browsers routinely so feel free to decline sharing cookies, use "incognito" browser mode, perhaps connect through a VPN if you don't want to be tracked especially on a public network (here's one I use). Google Analytics, AdSense, maybe a widget on the blog might use some of the cookie or IP info.

If you're responding to one of my surveys, blind tests, or contacting me by E-mail, unless you choose to do so, I will not have any need for your private information unless we get to know each other or plan to meet up, etc.

Otherwise, Happy 2024! May your life be free from scammers, spammers, identity hackers, snake-oil salesmen, and general crooks in the coming years! Peace.😌

Merry Christmas & Happy 2024! A year in review, final MQA sales, and have a very Spatial Christmas. 🎅

Hey everyone, I want to post a holiday greeting and retrospective as we end off 2023 and as I wander off for some R&R down south. This has been an interesting year I think in the world of audio. In my journeys through audiophilia, it's the year I'll remember as one of continued evolution in the fidelity of various components and further maturation of technologies available to consumers at very reasonable prices - specifically amplifiers.

2023 also marks the point of crossing 10M hits to this blog according to Google's analytics which is I think a significant numerical milestone. Not bad I think given my pace of sub-weekly posts, dealing primarily with topics that attract a relatively small group of hobbyists. While some of these technically-oriented articles probably are a bit beyond the interest of many audiophiles, I do hope that in time, the "average" hobbyist will see them as presenting some foundational knowledge that we should all know about the technologies we buy, and expressing a worldview that those who assess the audiophile hobby more objectively would tend to focus on.

Let's have a little recap of some articles and ideas shared over the last 12 months...

MUSINGS: On the duplicity of hi-fi audio anti-measurers? The John DeVore example.

The Hall of Measurement Devices.

"When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind: it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be." --- Lord Kelvin, Popular Lectures and Addresses vol. 1 (1889) ‘Electrical Units of Measurement’, delivered 3 May 1883

"What is measured, improves." --- Peter Drucker (from The Effective Executive) 

"When performance is measured, performance improves. When performance is measured and reported back, the rate of improvement accelerates." --- Karl Pearson

A longstanding debate over the years in the audiophile pursuit sadly is that of whether measurements are important in audio. Obviously, to me, and I think the vast majority of the world, the answer is "Of course it does!". One does not need to be a scientist of Lord Kelvin's stature or a statistician like Pearson, or a management consultant like Drucker to see the wisdom of such a basic idea which probably is one of the founding principles giving rise to our modern technologically sophisticated world.

Can you think of a single technological pursuit where the use of measurement instruments of some sort isn't beneficial to help gauge the effectiveness, efficiency, or value of a device which has been invented, produced, or manufactured? Is this not doubly important if that devices is supposedly built to a high "standard", reportedly made with quality and care? Typically at a higher cost like the things of "high end" audio?

Well, apparently, there are supposedly respected people in the audiophile world, designers even, who seem to think otherwise about the importance of measurements...

Do bit-perfect digital sources affect a USB DAC's sound quality? [2023 Edition - phone, Raspberry Pi, MiniPC, laptop]

In the image above, we see embedded some pictures of contemporary, expensive (>US$10k) 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 $10k streamer lying around here, but a $1000 phone could be different from a sub-$100 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.

MUSINGS: Beyond "High Resolution" recordings. Into "Immersive" and "High Reality" content.

The other day, I was reading this interesting article about someone upgrading his computer gaming gear to the latest and greatest, only to find that it ultimately made no meaningful difference for today's games that he's playing. No surprise? (As discussed a couple months back, I upgraded to the nVidia RTX 4090 but not for gaming.)

As tech hobbyists, it's important not just to be aware of what we could buy, but more importantly, what is it that buying the hardware would achieve.

Human sensory systems are not infinite - whether it's the angular resolution of vision, or how many frames per second we need for gaming before it's no longer noticeable (upper limit I've seen maybe 75fps?). So too, there's only so much audio frequency bandwidth or dBs of dynamic range we need to more than saturate our auditory limits.

To me, it's not good enough to just be fed information from the usual magazines or advertisers or reviewers, it's more important to understand what it is that the technology is able to do and by doing so, we understand what we really need, and have a chance to anticipate what we might be looking for ahead instead of being unduly externally influenced.

In this spirit, let's take some time to consider the road ahead. After all these years, where is progress to come from? Let's think about this...

How-To: Resurrecting bad BIOS update with CH341 USB EEPROM Programmer (AMD AM4 motherboard, 1.8V flash example).

Let's do a quickie post this week.

As per the discussions last time, I've been doing some computer upgrades here at home and at one point a few weeks back, I was updating the BIOS on my AM4 MSI X370 SLI Plus motherboard but accidentally disrupted the power in the middle of the flash!

This basically "bricked" the machine because this particular board only has one BIOS bank and there are no facilities to reflash. Since my AMD Ryzen 7 1700 CPU is still a very reasonable 8-core processor that can still be used for many applications these days, I looked for an inexpensive way to fix this BIOS mistake. The solution is the package shown above - a CH341 24 and 25-Series EEPROM Flash Programmer (less than US$15, this item on Amazon Canada).

Why not? 😉 AMD Ryzen 9 5950X Workstation & Ryzen 7 5700X Gaming CPU upgrades. Slowing pace of obsolescence & hardware waste for Windows 11 compatibility?

Although typically I write about audio stuff on these blog pages, not infrequently I'll talk about my computer updates as well. Looking back, this has allowed me to review the journey along the way over the last decade. As we enter into the Christmas season this year, I think this is a good time to be looking at computer parts as prices of things like SSD drives and DRAM in particular seem to be very attractive with DDR4 and DDR5 memory trending down, M.2 SSD likewise appearing to be bottoming over the last 18 months perhaps as the cost of basic necessities (food, housing, gas) have risen and disposable income reduced. I would not be surprised if inflation starts to drop in 2024 while the electronics parts rise in price again.

Who knows exactly what the future brings, but this looks like one of the best time to grab something like a 2TB M.2 SSD or some RAM:

The trend isn't as obvious with CPU prices. However, I upgraded my Workstation computer recently to the AMD Ryzen 9 5950X CPU - 16-cores, 32-threads I found at a decent price. And since it has been ages, I also updated my Gaming PC in the living room for the heck of it to the Ryzen 7 5700X.

MUSINGS: Multichannel mixes are more dynamic than 2-channel, stereo releases. (Going beyond 2-channel stereo legacy.)

Last week, in the Part II review of the Topping PA5II+ amplifier, I talked about a few albums like The Rolling Stones' Hackney Diamonds and the sound quality of the album. For years now, I'm been unhappy with the status quo of ubiquitous Loudness War, dynamic compressed albums. We've even explored using DSP to artificially improve the content for example.

A complaint I have with the Stones album is that the dynamic range of the CD is poor at DR6; and yes, this is an audible limitation. However, if you like this album, I recommend listening to the multichannel/Atmos stream or grabbing the limited edition BluRay import box with 7.1 TrueHD-Atmos mix which is much less compressed, with album dynamics averaging DR12!

[For simplicity, I'll stick with the DR "crest factor" result due to familiarity for many of us. These days we can talk about LUFS, EBU R128, etc. as discussed before as measurements of volume and for normalization. Check out the DR Database for results from many albums.]

In the last few years, I think some of us will have noticed this pattern of much more gentle use of dynamic compression in multichannel content. This is why a few months ago, I suggested that multichannel streaming simply sounds better than standard stereo 2.0 to my ears (this possibility was also suggested back in late 2022 and discussing this Steve Wilson multichannel mix).

Let's have a look at some examples.

Part II: Topping PA5 Mk II Plus (PA5II+) Class D amplifier review. Power, Distortion, the Subjective and on Hi-Res amplification.

I mentioned previously that this is a very unobtrusive amp. With the shipped plastic protector off, notice the low contrast of the lettering with the black front makes it even less obtrusive! This was why I left the plastic protector on to take the photos last time to better show the labels for the switches.

I introduced the Topping PA5 Mk II Plus last time in Part I with some initial measurements. This time let's keep going as we explore the power capabilities of this little audio amplifier, examine playback fidelity, and discuss a bit of the subjective performance.

Unless otherwise specified, these measurements were done with the amplifier connected to standard 4Ω and 8Ω power resistors as load, both channels driven, 20Hz-20kHz bandwidth for distortion measurements, unweighted. The Linear Audio AutoRanger allowed automatic gain/attenuation to keep the signal from getting too "hot". Signal from the AutoRanger is fed to the prototype Cosmos Scaler as a preamp for the E1DA Cosmos ADC operating in mono mode. High resolution signal generator DAC is the SMSL DO100 connected to Intona USB isolator. No special cabling, the 3' female XLR-to-TRS balanced cable was just something decent and generic like this, likewise generic RCA was totally fine. Seriously audiophiles, that's all we need for hi-fi sound quality.

Let's get to it!

Part I: Topping PA5 Mk II Plus (PA5II+) Class D amplifier review. (And RME ADI-2 Remote, "cultural pressure" for subjectivist audiophile reviews to include measurements?)

Over the last few months, I've been exploring the performance of the TI TPA3255 Class D chip amps including the AIYIMA A08 Pro, Fosi Audio TB10D, and AOSHIDA A7. Overall, we've seen very good results from these little amplifiers and I think they represent a level of low-distortion performance at a price point that is very attractive to many hi-fi hobbyists.

Depending on the power supply mated to the amplifier, measurements have been showing low output impedance up to 10kHz typically (<0.2Ω up to 10kHz), something like 80+W into 4Ω with less than 0.1% THD+N, and a -80dB Triple-Tone TD+N result at 1W into 4Ω which is excellent considering the prices of these little amps typically at less than US$150 depending on the features you want like Bluetooth input, VU meter, etc.!

Given the track record of these TI devices so far, this time, let's look at another chip amp which is based on an undisclosed part, not the TPA3255, although I can confirm it is a TI TPA chip. In my discussions with John Yang at Topping, the intent is to allow audiophiles to judge the product based on sound quality merits rather than focus too much on exactly which Class D part was used since the design around the chip is very important. Fair enough, and that's exactly what we aim to do here anyways since even with the previous TPA3255 amps reviewed, there were objective differences to find even if subjectively, differences might not be as noticeable.

I bought this Topping PA5 Mk II Plus (which I'll abbreviate as PA5II+ for simplicity) myself from Amazon, currently around US$325 with the intent to use in my own system. Since I'm interested in "high-fidelity" (not merely "euphonia"), I was interested to see how well this would compete with the DIY Hypex nCore NC252MP we measured a few years back. I like the feature set that it offers. On paper, it should provide the power I need and if the hi-fidelity performance is excellent, it could certainly be a listening "reference" here even though to be honest, I still love the Hypex's capabilities and would have no issue with enjoying the music from the inexpensive TPA3255 devices either.

A Psychoacoustic Rationale for the Subjective Evaluation of Stereophonic Sound Systems by Reviewers and Audiophiles (Ralph Glasgal)

With the discussion of ambiophonics ("ambio") and crosstalk cancellation (XTC) last time, I came across a number of fascinating writings from Ralph Glasgal in the Ambiophonics Facebook group. The one below is one of them I think worth considering that I had not seen before, explicitly written as copyright-free. I've made some mild formatting edits and wording substitutions/additions for clarity as well as emphasis in areas I felt of importance. I trust this mildly edited version retains the full meaning and intent of the original found at the group above. A copy of this has been sent to Mr. Glasgal but I'm not sure if he's reviewing his E-mails or active in audio discussions these days in his 90s.

A Psychoacoustic Rationale for the Subjective Evaluation of Stereophonic Sound Systems by Reviewers and Audiophiles

By Ralph Glasgal, BEP, MSEE, AES, IEEE

glasgal@ambiophonics.org

(original text posted on Facebook - October 15, 2015)

The oft repeated assertion that high end components of stereo systems can only be truly evaluated by listening rather than by measurement or blind A/B testing by listening panels has been argued for decades now. The following text will, I believe, provide a psychoacoustic explanation of why this position is largely correct and not a question of practicing voodoo audio.

Very few audiophiles will want to read what follows since it is rather long, too technical, and not what they are used to reading in Stereophile or The Absolute Sound. But this article is for the record, for discussion forums, and to have it available for future debates. Anybody is free to use or forward this text. It is not copyrighted. Supporting technical references by a variety of authors are available at ambiophonics.org (mirrored).

Stereo Crosstalk Cancellation (XTC): A review by STC. And trying out uBACCH, ambeo.one, and AmbiophonicDSP VST plus Foobar foo_dsp_ambio plugins.

Hey everyone, it has been very busy as expected through September here at the Archimago household. As a result, I haven't been able to spend as much time on the audio hardware hobby (still very much enjoying the music of course!).

Over the years, you might have come across the term "crosstalk cancellation" (XTC) for speaker playback, words like "ambiophonics" or acronyms like "BACCH" may have passed by in your readings (for example great discussion on Reddit). For this blog post, let me ask an outspoken advocate of XTC to join for some guest content to discuss the reasons and techniques, and later on, we'll talk about a few DSPs one could try at home to experiment...

Take it away STC for Part I, I'll be back with STC for Part II, then I'll talk about trying some of the DSP options in Part III:

Part I: An introduction to XTC (by STC)

Crosstalk cancellation is an attempt to deliver stereo sound as it was meant to be played without the interaural crosstalk errors with loudspeakers (see Keele, 1986 for a technical exposition). Many listeners may not realize how much realism their high-end stereo hi-fi system is lacking until they hear a system with crosstalk-cancelled (or XTC for short) playback. It is like comparing a photo of a window with a view to an actual window looking out at the scenery. Or like watching Avatar in 2D versus 3D.

RIP MQA codec? (Yeah. On Lenbrook Group's acquisition of bankrupt MQA Ltd., and SCL6.)

Hey folks, it looks like the saga around MQA never ends, but I think they're just scraping the bottom of the barrel with one last crank of the hype machine with hopes that this is somehow face-saving as well. :-|

So as of yesterday (September 19, 2023) it appears that Canadian brand Lenbrook Group of Companies - NAD, PSB, Bluesound - has acquired the intellectual property for MQA. Let's talk about this.

As We Hear It: On requesting artists/albums to streaming services. (Plus adding more RAM and larger SSD to the computer workstation.)

Hey everyone, life's been very busy so not much time to think or work on audio stuff.

A few weeks back in my discussion of Qobuz in Canada, I said: "I'm curious, has anyone out there contacted their streaming service to request the addition of an artist or album? Were you able to get your requests included?"

Well, I received a number of responses, mostly from folks who were happy that Qobuz or TIDAL were able to oblige with putting their requests up. Here's a very well written one that I thought would be good to share with everyone... It brings up important points especially these days as we transition into more music lovers depending on the services to supply our music. Many, including myself these days are collecting more playlists than actual physical albums or spending the time to download anymore.

MUSINGS: nVidia's GeForce RTX 4090. Power Limited Overclock settings. On technological progress into cognitive domains.

For this post, I thought I'd explore technological progress in the computing space. While I speak mainly about audio topics in these pages, I hope this post gives you an idea of the broader technological progress happening around us.

As per the image above, I've updated my workstation graphics card to a Gigabyte GeForce RTX 4090 Gaming OC. This card is truly a beast, covering 3.5 slots in the computer thanks to the extra vapor cooling chamber. [Related to this card is the slimmer Gigabyte GeForce RTX 4090 WindForce V2 that "just" takes up 3 slots.]

Years ago in 2017, I spoke about my GTX 1080 used in the game machine of that time. Since then, it's obvious that technology has moved forward very substantially! Every couple years has seen a new generation of graphics cards churned out by nVidia typically with AMD following suit and these days Intel making headway with their more budget-friendly ARC line.

With each iteration, we're seeing objective improvements in computational ability and physical characteristics like the shrinkage of the transistor "process" from 16nm for the GTX 1080 down to the 5nm (near limits of silicon) in the RTX 4090 today. With the ability to fit more transistors into a smaller area (higher density), the number of parallel computational cores has increased from 2560 shading cores (also known as CUDA cores) in the GTX 1080 to 16384 units in the RTX 4090, a 6.4x increase in this one metric alone; not to mention the addition of new features like the Tensor cores (high speed, mixed precision, high-dimensional matrix multiplications) released in the RTX 20*0 generation, important in deep-learning tasks.

Part II: Comparison of Bluetooth Fidelity - AAC encoder quality (Android 10 & 13, Windows 11, Apple iPhones & Mac)

Greeting everyone, time to jump into Part II of our assessment of lossy Bluetooth music transmission.

In Part I, we examined the use of an Android 10 device (Huawei P30 Pro) as audio transmitter showing the differences between the codecs as played back with the AIYIMA A08 PRO amplifier and its Qualcomm QCC5125 Bluetooth SoC. Please refer to that article for details about the methodology and comparison with the output from a high resolution Topping desktop DAC.

For this Part II, let's focus on the Advanced Audio Coding (AAC) codec which has become a very popular option. Other than the universal default SBC, AAC is probably the most common one for music transmission on account of the fact that the "elephant in the room" - Apple - uses this across its product lines as their standard codec running at 256kbps. Given the amount of use, this is basically a practical standard for quality music transmission over Bluetooth.

Given the broad range of computers/tablets/phones used among family members here, when I'm looking for wireless headphones, I would want to make sure the device supports AAC; probably more so than aptX or LDAC.

Note that there is actually a "family" of AAC profiles from the early Low Complexity AAC (LC-AAC) originating in 1997 up to later versions like Extended High Efficiency AAC (xHE-AAC) released in 2012. As end users, we're generally not privy to such details so I'll just use the generic term "AAC" in this article.

Part I: Comparison of Bluetooth Fidelity - SBC, aptX, AAC, LDAC (Android 10 source)

Blue ring around power/volume knob = Bluetooth input.

I've been wanting to do this for awhile. The last time I had a look at Bluetooth playback quality was way back in the days of the Oppo Sonica DAC in 2017.

Bluetooth has been our ubiquitous wireless audio transmission technology for more than 2 decades now; Bluetooth 1.0 was released in 1999 but it took a few years for the number of supported devices to grow and costs to come down. Since then, with subsequent versions, we have seen an increase in bandwidth, codecs, transmission range, and power efficiency.

Currently, we are at Bluetooth 5.X (version 5.0 standard released 2016) with the potential for up to 2Mbps transfer rate and distance maximally up to 240m (800ft)! These are clearly ideal numbers. Bluetooth transmits in the 2.4GHz bandwidth like WiFi but can "hop" (Frequency Hopping Spread Spectrum) between 79 channels, 1MHz wide, so there are usually no issues with coexistence. 

Given the 2Mbps limitation, lossless audio transmission would be a problem. Lossless 16/44.1 stereo is already just over 1.4Mbps uncompressed. Yes, we could losslessly compress but compression ratios are variable. Due to inevitable errors in transmission plus protocol overhead, in practice, at most we should think of Bluetooth 5 as operating around 1Mbps reliably under reasonable, if not close to ideal, conditions with transmitter/receiver nearby.

The Different Types of Subjectivisms in Audiophilia (And How to Get Rid of Them) - guest Taylor Christensen

By Taylor Christensen

I joined the audiophile hobby less than 10 years ago, and, as a person who relies heavily on understanding and applying scientific literature in my day job, I was baffled (pun intended) to discover the extent to which the culture of this hobby is shaped by “pseudosciency” beliefs and even frank scientific ignorance, especially when considering the high prevalence of the audiophile community being well educated and affluent.

Since then, I have thought a lot about this phenomenon. Whenever I am trying to make sense of the world, I find that exhaustive, mutually exclusive categorizations help a great deal, and I have come up with such a categorization that helps me organize and understand the strange things we see in this culture.

To communicate clearly, I need to explicitly define any words whose definitions may be ambiguous – in this case especially, because they sound very similar. Therefore, let me start with three definitions.

The first one, which I will be using frequently throughout this article, is "subjectivism," which I am defining as "any false belief in audibility".

Contrast that with the second word I want to define: "subjectivity," which relates to a person having a personal preference.

REVIEW / MEASUREMENTS: AIYIMA A08 PRO - TI TPA3255 Class D amp with AAC/LDAC/AptX Bluetooth input. On "giant killers" and "CHEAP" amps. Goodbye TIDAL MQA.

Over the last while it has been interesting checking out some TI TPA3255 "PurePath" chip Class D audio amplifiers such as the Fosi Audio TB10D [Upgraded] and AOSHIDA A7.

As you can see in the image above, I've got another one to put on the test bench for a look and listen - the AIYIMA A08 PRO (currently <US$130). Depending who you read/listen/watch, you'll see supporters who like the amp, sometimes calling it a "giant killer" of sorts, such as this blog post, or there are detractors like Andrew Robinson who seem to think these kinds of amps are only good in the nearfield and below 60dB SPL (see from 10:30). We'll talk about this below. :-)

As usual, let's start with a peek at what you get for a low price...

Qobuz now in Canada. Finally, Roon integration and a taste of lossless multichannel streaming. Thoughts on the future of audio streaming.

Finally after all these years. Despite bugging them at least since RMAF2019, it has taken ages but at last as of April 2023, Qobuz is now available here in Canada. As you can see, price in Canadian dollars is reasonable at CDN$10.83/month yearly subscription or $13/month if you prefer month-to-month. I see a 60-day trial here; there are 3-month trials out there as well so look around for one that might apply to you.

With competition these days, the price is in line with other services offering up to 24/192 lossless hi-res content; here are the current prices in Canada:

Amazon Music HD - CDN$10.99/m ($8.99/m Prime members)
Apple Music Individual - CDN$10.99/m
Spotify Premium Individual (lossy Ogg Vorbis) - CDN$9.99/m
TIDAL HiFi (16/44.1) - CDN$9.99/m
TIDAL HiFi Plus (MQA, likely FLAC hi-res transition in August) - CDN$19.99/m.

Pacific Audio Fest 2023: Part III - Final show musings... On sponsorships, seminars, unique listening opportunities (DSD256 vinyl sounds great ;-), and suggestions.

Collected promo materials, PAF2023.

Having published on the products seen at PAF2023 in Parts I and II, I thought it would be interesting to take some time to chat about other experiences from this show and parting observations.

These observations might apply at other audiophile shows as well.

Pacific Audio Fest 2023: Part II - Hotel wing audio rooms. A few words on sound quality, and emotional connectedness.

 

Let's continue exploring Pacific Audio Fest 2023 beyond the main ballroom and larger rooms from last time. As you're probably aware, audio shows take place in hotels with companies renting out rooms to show off their gear. At PAF2023, we have 4 hotel "wings" to explore located on the first, second, and thirteenth floors.

Mercifully, PAF2023 isn't a big show which allowed me to enter each room and have a listen over the leisurely 3 days (Friday to Sunday) that I was in Seattle. Let's go for a stroll and see what each room had to offer. While I don't think I missed any of the rooms, I'll only highlight the ones that seemed most interesting...

Pacific Audio Fest 2023: Part I - Ballrooms, marketplaces, and the larger rooms... Thoughts on vinyl / LP at "hi-fi" demos.

At the time of publication, it will have been a week since the Pacific Audio Fest 2023 (June 23-25). Compared to last year, they held it about a month earlier. As usual, I took a number of photos at the show and figured it would be fun to do some reporting on what was seen and heard, offering impressions from my notes and memories of the time in Seattle.

To start, let me remind everyone that while audio shows are fun, they are definitely not the best places to listen for sound quality. This is better done at a local dealer showroom you might be familiar with or best in the comfort of home. Typically at shows, we're treated with unfamiliar music. Even if the song is familiar, they might be playing from a streaming remaster or off an unfamiliar LP. Room acoustics vary widely, and attendees are typically shifting in and out, chatting during the visit while you're trying to appreciate the music.

Nonetheless, there is something to be said about the importance of that first impression for attendees of what we hear. In an age where much of our purchasing habits come from online sources and web-based transactions, being in the presence of these devices, and the impressions they leave us with, are powerful in directing whether we're likely going to explore the brand or specific device. As such, if companies are going to attend audio shows, it is very important that they do it right.

REVIEW: Hidizs AP80 PRO-X Music Player - touchscreen, unbalanced and balanced headphone output, dual ESS ES9219C DAC. (And time for PAF 2023.)

Digital Audio Players (DAP) are not a class of components I've explored as thoroughly over here at the Musings. However, over the last few years, as smart phones have ditched their analogue headphone outputs opting for Bluetooth audio or (often cumbersome) DAC/headphone amp dongles, what's an audiophile to do when we want to listen to high-quality playback on the go? Perhaps a small DAP can satisfy this need.

Recently, the folks at Hidizs sent me one of their most recent Hidizs AP80 PRO-X (currently around US$200) for an honest review including objective testing of course. This is the 3rd evolution of the Hidizs DAP product line which started with the AP80 in 2018, followed by the AP80 Pro in 2020, and this newest AP80 PRO-X in 2022. As you can see with that picture of the device in my hand, it's a cute, flat, squarish music player measuring only 6.1x5.6x1.4cm, and weighs a mere 70g.

The aluminum and glass body, bright Samsung 480x360 2.45" touchscreen with good viewing angle, contrast and saturated colors, feels sturdy in the hand with convenient volume control knob, and 3 smaller physical buttons on the side.

Computer hardware thingies: Mediasonic Probox USB3.2 Gen 2 10Gbps enclosure, SODOLA 8-port 2.5GbE Switch, and if you need a good USB-C cable for DAC...

Hey there everyone, this week I thought I'd just put up some quicky comments/"reviews" of products I've found useful in the last while in my computer system and home network in case this might be of use to you. Nothing too fancy or necessarily even audiophile related for the most part.

First, there's this Mediasonic Probox 8-Drive USB3.2 Gen 2 10Gbps enclosure [H82-SU31C] (US$350). 

Box contents: IEC power cable, 8x plastic HDD handles and screws, 3' USB-C to USB-C cable.

In 2023, while we're getting there with high capacity "3D" and higher endurance SSD designs, we're not quite at par with the storage capacity afforded by multi-terabyte hard drives available at excellent prices. I'm sure most of us have been gathering our archive of digital memories and other media for years and have a need for all those terabytes at least backed up.

I've been using the older USB 3.0 + eSATA version (H82-SU3S2) of this device for >10 years already as a simple 3.5" HDD backup box which unfortunately went a bit flaky on me with occasional loss of connection in the last few months. Hence the upgrade to this newer model.

As per the description, this is a 10Gbps USB 3.2 Gen 2 device, the interface is USB-C; nothing else other than the power connector on the back and a few buttons and indicators up front. 

Beelink EQ12: Low power Intel N100-based Roon endpoint and Kodi 4K/HDR/60fps player, general Windows 11 computer. A few words on HDR10(+), Dolby Vision, AV1, and Kodi. And hilarious Transparent $$$ cables.

Beelink EQ12 MiniPC, some testing with the RME ADI-2 Pro FS R Black Edition.

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.

REVIEW: Beelink EQ12 Mini Computer - Intel N100 CPU (12th Gen, 4C/4T, 24EU iGPU), 8GB DDR5, 500GB NVMe. And on journalistic objectivity, truthfulness and non-neutrality.

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 US$250-300 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.

Retro DIY Headphone Amp - The Audio Amateur, Gary A. Galo design, built by Mitch Barnett circa 1991.

Every once awhile, I think it's fun to try something a little different!

While the vast majority of us audiophiles buy our stuff, as per all tech hobbies at one point, this began with hobbyists in their workshops, basements, and "caves" putting together electronics parts and enthusiast kits with soldering irons making their own stuff. I remember the days in the early '70s as a child when the hi-fi system at home was put together by my dad based on designs he found in the magazines. A time before commercialization of consumer electronics was anywhere like it is today.

With miniaturization and economy of scale, these days, it's more expensive to build one's own components (both time and money) and more than likely the sound quality would not be as good. Of course, there is an element of lasting pride in building something oneself which we can never really capture when purchased with a credit card. Major respect to the DIY guys and gals out there still designing and making their own gear.

So instead of a commercially available product, let's have a look at the device shown above. It's a home-made "prototype" headphone amp lent to me by Mitch Barnett (of Accurate Sound) built on a wooden board (I guess there might be some vibration control with that ;-). He built this something like 30 years ago based on a design published in The Audio Amateur (4/91, predecessor to today's AudioXpress) by Gary A. Galo. For a bit of background on The Audio Amateur, check out this thread and post from Palustris.

RESULTS: Internet Blind Test of 24-Bit vs. Dithered 16-Bit Part Deux - Daft Punk Edition

Well ladies and gentlemen, the time has come to reveal the results of the 2023 24-bit vs. 16-bit Internet Blind Test as laid out in the post: "Internet Blind Test: 24-Bit vs. Dithered 16-Bit Part Deux - Daft Punk Edition!".

This test was launched on March 4th and remained open to May 5, 2023; plenty of time I trust for folks who wanted to perform the test to listen and give me their results. As indicated in that invitation post, this test was created as a response to discussions on a message forum where it was said that 24-bit audio could be audibly differentiated from 16-bit files. It was offered in the discussions that the Daft Punk track "Giorgio by Moroder" from Random Access Memories, an album well-known to audiophiles, is an example of a well-produced, modern recording that benefits from 24-bits "high resolution". For years, it has been available for download at places like HDtracks, and Qobuz.

In this post, let's discuss how the test samples were created, reveal which sample is the high resolution version, and results from the respondents. Grab a drink, let's have a peek... ;-)

Audiophile Survey, early 2023: Who we are (including age and gender). What we use. How we think.

Well ladies and gentlemen, thanks to all who took the time to complete the information in the open "SURVEY: What audio playback system and/or streaming music service are you using in 2023?" post. The survey collected responses from February 11 to May 5, 2023 on this blog, and as usual, the responses came from audio lovers around the world, receiving in total 1330 entries with general information on demographics, broadly what kinds of systems are being used, multichannel playback, interest in masterings, and for those using streaming subscriptions, which ones.

As with any survey, we have to start with some context for the data. Obviously, the individuals who submitted results to me would have been primarily the viewers on this blog although I know the survey was advertised at various audiophile-related forums. I did not do any special advertising personally, other than mentioning it on a few forums I visited like Audiophile Style or Steve Hoffman Forum. I don't maintain much of a social media presence so basically just let the survey diffuse across the Internet.

Given the nature of this blog and its contents, I'd like to think that this survey will tell us about some of the characteristics of the subgroup of intelligent, reasonable, balanced, technically savvy, prudently skeptical, practical audiophiles around the world in the first half of 2023. ;-)

Musings & Meditations on the intersections between clinical care and audiophilia.

The "Monastery" of Petra (Jordan); carved out probably around 1st Century CE. Harder to get to, but I thought this was just as awe inspiring as the "Treasury" made famous in "Indiana Jones and the Last Crusade".

In the last month, I had the pleasure of travelling through Jordan and Israel. As I pondered on some of the sights and sounds of the ancient civilizations, I wondered among other things, perhaps not surprisingly, on the audiophile pursuit for the purposes on this blog. :-)

Regardless of culture, we as humans share the same universal hopes, fears, and desires as we carve out a place in this world for our families and ourselves. Whether it's with a street vendor in Amman or some guy in a Shanghai night market, haggling over the best price for a souvenir T-shirt is essentially the same process. Nobody wants a bad deal, or items below expected quality.

We can discuss academically about the mechanisms of price discovery, study the complex verbal and nonverbal negotiation techniques, or explore macroeconomic determinants of supply and demand. Whether it’s getting a decent T-shirt or purchasing "high-fidelity" audio products, as consumers, value is always a core consideration as I've discussed many times over the years as a recurring theme (including here, here and here).

Coincidentally, a few weeks prior to leaving on vacation, I had a discussion on Audiophile Style with Andrew Quint who writes for The Absolute Sound. Like him, I work as a doctor and engage in the art and science of clinical care of and with people every day while pursuing the audiophile hobby in my free time. Over the years, I have virtually met some of you on forums and through E-mails also coming from clinical backgrounds whether as pharmacist, psychologists, therapists, nurses, etc. This article germinated during my travels as I thought about the complexity of clinical care and likewise some of the complexities that arise in audiophile discussions. Thankfully, related themes are nowhere as complicated or potentially perilous for us audiophiles and the epistemological debates among us seem safely parabolical of more significant ideological differences beyond just this little hobby sandbox

Since clinical care is a huge topic, permit me to talk somewhat loosely about some points of intersection since I think these factors have affected my attitudes toward the audiophile hobby and informed the judgments I make when reviewing products contained in these pages. These ideas may resonate with your own thinking as an audiophile.

(Along the way in this article, let me show you some pictures I took during the vacation!)

MEASUREMENTS: Fosi Audio TB10D [Upgraded Version] stereo amplifier (TI TPA3255 Class D). Ethernet is inherently "isolated".

 

Not much time this week to play with the toys as I'll be heading off on vacation for a few weeks. However, I did receive the Fosi Audio TB10D [Updated Version] (<US$80) above recently that I wanted to use as an inexpensive "utility" amplifier for various measurements and experiments. It's also based on the TI TPA3255 Class D chip amplifier; same as the AOSHIDA A7 recently reviewed.

As you can see in the unboxed picture above, there are no frills, just the amplifier and a 32V/5A power supply (same specs as AOSHIDA).

This is the "Updated Version" with improvements as discussed by the Cheap Audio Man back in late 2022. Presumably this update was released around September or October 2022. I see ASR measured this amplifier in September 2022 - not sure which version that was. I purchased this amp from the usual retail channels.

Due to the time constraints, I'll focus more on "core" measurements and compare especially to the AOSHIDA.

As We Hear It: Innomaker HiFi DAC Pro HAT review by Doug Gardner. And MQA is bankrupt; the end is here.

Arch,

I’ve been following along with your experiments using the Cosmos ADC and APU to test a variety of gear and I’ve put together a similar setup to do some measurements too. I’m sharing some results from testing I’ve done of the Innomaker HiFi DAC Pro HAT for the Raspberry Pi. I bought the DAC for US$89 directly from Innomaker for use in my home office.

My home office system is headphones only using the Drop THX-789 headphone amplifier fed by a Khadas Tone1 (Tone Board Generic Edition) DAC connected via USB to a Raspberry Pi 4 with display running RopieeeXL. Music playback software is Roon with Drop+Dan Clark Aeon X, Aeon Noire, or Drop x Sennheiser HD6XX headphones with PEQ settings from Oratory1990 to make the physical sounds. This setup gives me a clean and compact footprint with a touch screen for ease of use and objectively good fidelity per the measurements and reviews performed by you here on your blog and by Amir over at Audio Science Review. A drawback to this setup is that the Tone1, sitting in a separate box and with the USB and unbalanced audio cables, makes for additional clutter on the desk.

The Innomaker HiFi DAC Pro uses the same DAC chip, ESS 9038Q2M, as the Khadas Tone1 but, unlike the Tone1 Generic, is HAT compatible and has both balanced and unbalanced output. Balanced output is via two 3.5mm headphone jacks and unbalanced through a single 3.5mm output that can also serve as headphone out. I chose to use the balanced outputs. I assembled 3.5mm to XLR cables from spare Amazon cables I had on hand. No need for anything flashy on the cable front. If you don’t want to roll your own then you can buy 3.5mm to XLR cables from Innomaker’s Amazon store. It should sound like the Tone1, right?

MEASUREMENTS: Topping HS02 USB 2.0 isolator. (This works with the E1DA Cosmos ADC; and the Topping + Intona "double isolation" of DAC and ADC.)

Hey guys and gals, I must be a sucker for relatively inexpensive USB galvanic isolators. To be honest, this is mostly because I look for ways to lower noise on my measurement testbench, not that I'm concerned with the actual audiophile sound system these days! ;-)

Today, let's have a look at the recently released Topping HS02 USB2.0 isolator (currently ~US$100). This is an update to the previously reviewed HS01 last year. As you can see from the picture and specs, the box now has selectable USB-A/B connectors or USB-C. Isolation is not just applied to the in/out USB data connectors, but also the auxiliary power input with filtering which means the device could stay free of noise even if we plug in a power source with some noise in it. As usual, be mindful of power-hungry USB-powered devices which will require auxiliary power input.

Furthermore, Topping has improved compatibility now with the ability to negotiate USB2.0 low (1.5Mbps)/full (12Mbps)/high speeds (480Mbps). I can confirm that my low speed wireless keyboard dongle works fine.

The diagram showing the path of the data and power connections is relatively clear printed on top. Inside the box are a couple of pamphlets - the black one is the warranty card and Topping catalogue, and the white user manual. There's a short USB-A to USB-B cable in the plastic bag.

RETRO-AUTOPSY: Museatex Melior BS-1 Bitstream S/PDIF DAC (circa 1995?). A few words about external clocks for audiophiles. And a speaker cable blind test?

The company Museatex was formed around 1990 by Ed Meitner and John Wright based in Calgary, Alberta, Canada. Over the years, the brand was assumed under A/D/S which eventually closed in 2001. There's still a web page for information on Museatex products here. Ed Meitner has moved on these days to EMM Labs since 1998 and given his work with SACD, his name has been associated with "bitstream" type technologies since (some more info/video).

By the end of the 1980's, 1-bit Philips "Bitstream" PDM DAC chips started to show up in the market with the Philips SAA 7321 chip as one of the 1st generation devices (see Stereophile reporting back in 1989). Some of these chips were incorporated in CD players like the Meridian 208 that came out in early 1990, well-reviewed by Paul Miller in High Fidelity.

By 1991, the "second generation" Philips SAA 7350 "bitstream" DAC became available, capable of taking up to 20-bit PCM (from 16-53kHz sample rate) and upsampling to 1-bit SDM applying 3rd order noise shaping (some more history here). It is this DAC chip that's at the heart of the Museatex Melior Bitstream DAC, I believe first released in 1992. Here are the specs from the company.

The exact history of this particular unit I had access to has been shrouded in the sands of time, but was probably purchased around 1995. The original suggested price on one of these was US$899 which would be about equivalent to over US$1500 in 2023. Even to this day, I've seen comments from audiophiles who have a special affinity to the sound of this vintage DAC. Claims to fame included anti-jitter input circuitry (supposedly reducing "glare and harshness"), a custom digital filter allowing for "more accurate signal conversion", and high quality power supply with line noise filtering.

Thanks again to my friend linnrd for digging this unit out from his audio device archives. While externally it looks to be in very good shape, unfortunately, it didn't quite power up normally for me which sadly resulted in this article being more of an "autopsy" rather than actual measurements. I guess having a look inside is still better than nothing for historical documentation if nothing else.

REVIEW/MEASUREMENTS: AOSHIDA A7 Class D TI TPA3255 amplifier. Good sound. Good power. Economical.

Above, you see the small AOSHIDA A7 Class D amplifier which we'll go in depth with in this post. It's inexpensive and can be purchased for less than US$150 these days. This design is also sold as the Douk Audio H7 with a different color scheme, presumably the innards must be very similar if not identical. I preferred the look of the black AOSHIDA version with orange-ringed VU meter. I purchased this amplifier through the usual retail channels.

Over the years, it has been good to see the evolution of Class D designs and the inexpensive "chip" amplifiers. Internally, this is based on the TI TPA3255 "PurePath" chip (released in 2016) rated to provide up to 315Wpc into 4Ω stereo but at 10% THD when provided with adequate power (data sheet max is 53.5V). Notice the italics to emphasize that these numbers must be put into context. For audiophiles who want lower distortion in their amps (like <1% THD), we would be looking at much more conservative power figures than that 300+W being promoted for these amps.

(The chip also has a mono configuration that's spec'ed at up to 600W into 2Ω which would not apply for this review.)

The Audiophile Wisdom of ChatGPT (Feb 13, 2023 Version): Learnings from an artificial intellect on an esoteric hobby. (And on creativity?)

I'm sure none of us these days have escaped news about ChatGPT from OpenAI. Articles have been ubiquitous covering the implications of what this "chatbot" is able to do. No doubt, there will be deep implications stemming from this technology already being debated through the halls of academia on how it will affect everything from education, to work, to legal ramifications. As with any likely transformative technology, there will be promise and fear.

Already, I've seen many articles out there including in our little corner of the universe with Stereophile's "As We See It" in February referencing ChatGPT.

As you're likely aware, ChatGPT achieves its remarkable abilities based on Generative Pre-trained Transformer (GPT-3.5) "large language model", a sophisticated "self-supervised" general AI model based on >175B parameters combed through 570GB of data as text off the Internet, books, and Wikipedia. Yes, human feedback is part of the training process and data continues to be gathered from users to improve the model. At the time of this article, the openly available online ChatGPT has been trained with data up until September 2021 as can be seen here:

Arch: Who won the Superbowl in 2023?

ChatGPT: I'm sorry, but I am not capable of predicting future events as I am a machine learning model trained on historical data. As of my knowledge cutoff date, which is in September 2021, the most recent Super Bowl was Super Bowl LVII and it has not happened yet. It is scheduled to take place on February 5, 2023, so we won't know the winner until the game is played.

Given the level of knowledge ChatGPT has access to, I wondered how would it perform currently in March 2023 if asked about broad audiophile topics. I think this is interesting because the answers it gives must be an integration of all those hundreds of gigabytes of texts fed into the system. What does all that information teach the machine about the current understanding of audiophile topics? Are the answers reasonable, and relatively free of errors? Do the answers show "common sense" or even a level of "wisdom" one might wish to receive when talking to a knowledgeable audiophile friend requesting advice?

Let's dive into a Q&A discussion and see what ChatGPT can tell us about this niche audiophile hobby... (Grab a warm beverage by the fireside friends, we go deep and broad.)