Part III: Topping DX9 "15th Anniversary" Limited Edition DAC & Headphone Amplifier - DSD, S/PDIF inputs, headphone out, pre-out, and AMPT. And the desire beyond Perceptibly Perfect.

With Raspberry Pi 'Touch' streamer showing album art running RoPieee, and the Topping DX9 VU meters playing, this looks quite nice in the audio rack!

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.

Camera upgrade: Sony (Alpha) α6700 mirrorless camera with 18-135mm f/3.5-6.5 OSS kit lens. 🙂

Hey guys and gals, just thought I'd throw in a little something this week not related to audio as I finish some further measurements on the Topping DX9 DAC I've been talking about over the last couple weeks. As I noted last time, I found an unexpected 192kHz frequency response anomaly with the DAC and I know Topping are looking into it. So I figure I'd give it a bit more time to see if they can get an updated fix out before I publish Part III. Always good I think to publish the "freshest" data.

So, this week, let's do a little show-and-tell for my new travel camera - the Sony α6700 APS-C mirrorless camera with its 18-135mm/f3.5-5.6 kit lens (~US$1400 body only, US$1800 with lens).

Part II: Topping DX9 "15th Anniversary" Limited Edition DAC & Headphone Amplifier - PCM Filters, Frequency Response & DAC Resolution. (And Trump's ongoing oblivious narcissistic tariff buffoonery.) [Firmware 1.23 Update]

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.

Part I: Topping DX9 "15th Anniversary" Limited Edition DAC & Headphone Amplifier - build, features, listening impressions & subjective luxury.

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 (US$1299, CAD$1900, depending on tariffs you might do better ordering from China through AliExpress):

This is Topping's flagship DAC, released in late 2023. It's said to be limited edition due to the restricted number of DAC chips; I connected with Topping and was told in total they made about 1800 units.

I bought this unit from the usual retail channels and have no affiliation with the company.

Multichannel/Atmos 3D Audio Walkthrough. The idea that DACs sound about the same. Countercultural & honest audiophiles?

Hey audiophiles, I've been wanting to do this for awhile now. Back in 2021 when I wrote about "Spatial Audio" music streaming on Apple Music, in the back of my mind I was thinking it would be pretty cool to not just listen to the music and consider whether this kind of content is worthy of audiophile exploration, but to actually fire up a DAW (digital audio workstation) and play around with Dolby Atmos myself to create a little something that I can also use as a demo or to help with set-up in my own room.

Nothing too fancy of course since the intent is to demo spatial capability rather than wow the listener with overly complex sounds or movements. It's also a fun way for me to learn how to use the software and to go a bit deeper into 3D audio - beyond just expressing opinions on the consumption side.

So, over the Spring Break with a little more time available, I bought a copy of DaVinci Resolve Studio 19 (currently US$300) and got to work on figuring out how to author some 3D audio content. The price is very reasonable for such a powerful piece of software which I plan to use in other audio/video projects. Other packages that allow Atmos audio mastering include Avid's ProTools, Steinberg's Nuendo and Cubase, Ableton Live, Apple's Logic Pro and Final Cut Pro.

Once I figured out how the Fairlight "audio console" module in DaVinci Resolve worked and got the immersive pieces authored, a friend who works in audio professionally helped with the Dolby Media Encoder (US$400/year subscription) side to bring the track over to Dolby Digital Plus / EAC3-JOC, TrueHD-Atmos, and AC-4 IMS.