Detailed THD(+N) vs. Output Level Measurements of ESS ES9039Q2M. Balanced output quality from Hidizs AP80 PRO-X DAP. And Tekton's self-inflicted PR disaster.

Hey everyone, I wanted to post a follow-up of sorts to a couple of previous articles. First, the article "Hi-Res THD(+N) vs. Output Level Measurements (ESS "HyperStream" vs. AKM vs. TI/Burr-Brown). And a bonus R-2R!" was published back in the summer of 2022 showing an interesting sinusoidal pattern in the harmonic distortions with ESS DACs.

Since then, with the release of their newest ES9039 DACs which employ their latest "HyperStream IV" modulator, I thought it'd be cool to have another look...

Another follow-up is a look at the 2.5mm balanced output from the Hidizs AP80 PRO-X Music Player which was measured last year. At that time I didn't do the balanced output measurements so let's capture a few metrics and compare this with the single-ended 3.5mm output.

We can then end off with some audiophile social commentary from this week's drama.

EARLY LOOK (Part I): E1DA #9039S USB Balanced DAC/headphone amp - Super Hi-Res, Tiny Package! Also, let's tweak...

Hey everyone, it's time to have another look at a product from the engineering workshop of Ivan Khlyupin (IVX) at E1DA - the E1DA #9039S:

Notice balanced 2.5mm TRRS phono output.

As you can see, it's a prototype/preproduction (depending on whether the circuit could still change) unit with pen markings on the box for the number "9" to make sure the correct product was sent my way. 🙂

This is the latest iteration of E1DA's line of USB2.0 dongle DACs which includes the E1DA #9038D6K I had a look/listen to in late 2022. As you likely surmised, this update is based on the next generation of ESS Sabre DACs - the low-power, 2-channel, ES9039Q2M, using their sigma-delta Hyperstream IV modulator. The chip specifications list 130dB of dynamic range, -126dB THD and -120dB THD+N. We'll see in a little bit what Ivan has been able to "cook up" in his lab including some performance results. Back in 2022 with the #9038D6K DAC, he had already achieved -120dB THD+N (120dB SINAD) with single-ended output. How much better does it get!?*

As I sometimes do, due to time limitations, I'll split this write-up into 2 portions to present different roles/functions of the device. For today's Part I, let's just focus on the usual look-and-feel as well as using this device as a straight, unloaded balanced DAC. This will give us an idea of the performance capabilities of the ES9039Q2M in the hands of an experienced engineer. Next time we'll examine this device as a headphone amp.

The current anticipated price for this USB DAC/amp is presumably going to be less than US$150; I believe the exact number is still being crunched.

[* Asking how much better in terms of THD+N is of course a different question from "How much resolution does a person need for excellent high-fidelity reproduction?"!]

MEASUREMENTS: Review of AudioQuest JitterBug FMJ. (And on Milind Kunchur's recent RCA vs. XLR paper.)

Hmmm... What does "LESS DIGITAL NOISE" actually mean? After all, noise that's bad enough to affect digital data will result in errors. Obviously, that would be very bad!

Normally, I don't review stuff like this because there's simply little reason to believe these kind of things do anything of value.

I know, this comes across as highly biased right at the start of a review post! But I want to be honest and I wasn't born yesterday so I know there are all kinds of claims in the audiophile world that simply do not pan out. Furthermore, I've had experience with the AudioQuest company (see the Dragonfly Cobalt / Red / V1.2 DAC review a few years back) and know that they have made claims which turn out to be untrue when tested.

Another admission going into this is that I was introduced to the AQ JitterBug back in 2015, and over the years I have seen other tests like the Audio Science Review thread from 2019. Having said this, I am happy to be swayed if I truly hear a difference or measurements show me that I should change my mind.

So, when a local audiophile friend bought the new AudioQuest Jitterbug FMJ ["Full Metal Jacket" - cute] (~US$60, released mid-May 2021) and suggested I borrow it for a week as he went on vacation, I figured it would be fair to give it a try and see if I can run some measurements to provide data to audiophiles at large on this update to the product. I promised him that I would give him my honest opinion.

MEASUREMENTS: It's Balanced PonoPlayer Time...

As promised in my previous post on the PonoPlayer, I was going to be getting some 1/8" TRS-to-XLR balanced cables to try out with the PonoPlayer. Mainly I just wanted to see for myself the optimal level of functioning for this device... Already the unbalanced output is capable of respectably low noise and very reasonable distortion numbers especially with high samplerate material for a portable device. I therefore expect the balanced output to be better. As you see in the image above, those cables arrived; inexpensive ones off eBay at about $12USD for the two from China.