2018 Mar Update
* Part I: The art and goal of analog output and player design of Wave
From time to time, in the non-audiophile world, we often get this question: Why you will need a dedicated audio player since you have your smartphone? Even today, a lot of earbud passionate people still pair their $1000+ earbuds with their definitely not good sounding smartphone. Indeed, smartphone has its virtue. You will carry it all the time, it has all kinds of network connection. and you could use that to see Youtube music videos whenever you want.
Well, our design goal of an Audio Player is always dedicated to two things which are essential for the people who really care and would like to trouble themselves to bring another “device” with them besides a smartphone.
(1) A significant improvement on sound quality for all kinds of earbuds and headphones.
A usual smartphone has roughly less than $10 BOM cost on headphone functionality, or they’ll even just skip the analog headphone output at once.
Wave has dedicated super quiet power design, 8 layer PCB with great ground shielding, best headphone amplifier circuit and best quality passive components.
It can handle the super sensitive earbud, CIEM or 10+ balanced armature $5K+, to mega hit big cans like Utopia, LCD-4 or HD800s or many others you prefer.
We hope with Wave, you could hear a BIG difference.
In order to do that, we will need to get the following results:
(A) When Wave is driving earbuds, super sensitive one or any impedance under 32 Ohm, we need to have a super BLACK background, crazy low noise floor, and wonderful coherence from deep bass all the way up to more than 30K Hz.
(B) When Wave is driving the big cans, we need to have enough driving power and definitely kick-ass energy when called for because these guys need it. The slew rate of voltage and current changing ability needs to be super good, so you could get the true potential of these big guys.
In one sentence, our goal is making your earbud and headphone sound as good as it should be. Not less.
This update is about this goal and the current great results we have.
(2) A significant improvement on the digital part including music storage size and data transfer jitter.
This is another place where almost all smartphones fail. Regardless if you bought 256G or 128G smartphone with you, after applications, photos, videos, and tons of other stuff, most people may only have around 32G space for music, or even less?
Wave starts with 64G size all the way to 256G. Our Operation System and all other data will sit beside this space. This space is dedicated to music, and music only, with two full size SD cards, which is still an unique design in the market. This will give you a definitely nice space for your uncompressed and lossless high-def music.
"Jitter control" is where both popular iOS/Android system don't care. And smartphone's design is all innocently ignoring it in audio signal path.
We will show one graph here to display the result from Wave. We will leave the rest of good results about digital part in another update to prevent this update becoming too long.
This is the 1K Sine wave direct output. We use FFT on Audio Precision to show the result above. As you could see the 1K signal is straight up to -0dB and with ZERO side band around. The noise floor is nicely located at -120dB (!!) which is definitely not bad considering this is a space tighten portable audio device. The result is CLEAN and CLEAN. This board does have dual Femto clocks option there. But the whole great work was done not only by clocks, but also the buffer, clock distributors, I2S line, even PCB digital line layout.
When there is some jitter in audio signal path, usually you could see the graphics like the following. (This is a direct quote from Stereophile's test result of Rega DAC by admirable John Atkinson) https://www.stereophile.com/content/rega-dac-da-processor-measurements
For now, very very few portable audio player publishes their jitter test results. So we randomly picked one desktop DAC here. (P.S.: I loved Rega's product when I was 20)
Before we send these nice Wave boards out to software team for more integration, we are really excited to put some good analog related test results here. And without "adjectives", we hope solid numbers and real life test is the best!
1. Left of Larry is the very best Audio Precision machine which measures the noise, features, THD, etc.
2. Middle screens: firmware code, control power output, software integration, Gerber for the Wave in the middle.
3. Right hand side lower part: 10G scope for digital signals, and a solder station for any fixes necessary.
(A) The static noise when there is no "music" or signal
In our measurement, for the bandwidth from 20Hz to 20K Hz. The total accumulative noise in RMS is 32uV. Yes. That is 32 * 10 ^ -6 Volt. So every CIEM, super sensitive users could be very comfortable now. Pure black between every music note you hear.
(Condition: This test result was taken from the Wave board with the IEM configuration. We put tons of goodies there to make sure noise is totally gone.)
Also, we’ll show you the FFT here.
A good flat line from 20 to 20K on average below -130dBrA here (we set the reference in 1V rms). You might ask: what is that little peak around 1.2 KHz below -105dB? Frankly, we are hunting that down too. Should be some signal interference out there. Or maybe after we put the chassis and shield there, it should be even better.
(B) THD+N ratio
One of the most important playback results index. The THD + N (Total Harmonic Distortion plus noise) ratio... We are happily at 0.001299%. Measure in 45K Hz bandwidth. (Be aware, it is our tradition to use 45K Hz bandwidth). If we use 20K Hz, the result would be even better.
Also, the test condition is on the load of 300 Ohm which is a classical BIG load for headphone amplifiers. (Yes, HD800 and HD800s users. Please be happy here)
(C) Frequency Response
This usually won't be a problem for a decent DAC or DAP. But we still put it here. And one thing we want to show: the low pass filter we used here is an "Analog" one. We didn't use DAC IC's internal upsampling to maintain the best BIT PERFECT! We already let software team add a switch in the menu, so to make sure if any user loves to use digital filter to filter out the high frequency side-band noise, we could let them do that too. And the default is OFF. This is also a good sounding tradition from our flagship DAC. We insist on Bit Perfect.
(D) DSD64 and DSD128 Playback
The rabbit is out. Yes. Wave can play the DSD file nicely. We use native DSD signal within our internal digital audio path. And ESS DAC directly receives from our 3 Layer Buffer of these DSD signals. Direct in, direct out. And I believe some of you would still remember, we only use ESS DAC as the best core and we do all the related digital process, buffering and IV conversion by ourselves. (Yes, this took more components and time and cost and a lot of stuff. But this is definitely worth it)
Let me put DSD128's (DSD 5.6M) FFT here. Our Audio Precision could show all bandwidth all the way to 1MHz (no kidding) and as you can see I use 10G scope all the time to trace down stuff. So our result here is quite amazing!
I put the scope upper limit to 50 KHz. Yes. All above even Sony’s Hi-Res golden sticker requirement. You could see all Wave player’s harmonics are lovely below -120dB to -110dB all the way up to 50K.
And some of you could see a minor raising up of noise floor from 40K. Why? Don’t worry. Nothing to worry about here. This noise floor raise up is very typical when you playback DSD files.
DSD128 will have the noise floor raising from around 44 KHz. DSD256 will start from around 88K Hz. Sadly, DSD64 (DSD 2.8M) will start that from 22 KHz.
Above graph is also hard evidence of Wave truly playing DSD file as NATIVE DSD! Because you could see the typical DSD playback noise floor raising character here.
I saw some people are always worried about if their DAP is truly treating DSD as the DSD. Or secretly converted into PCM in some process? When you use the FFT, you could see everything like an X ray. Super clear. Nothing could hide.
One final graph is Wave playback of DSD64 (DSD 2.8M)
*** Don’t get scared ***
Before 22 KHz, everything looks exactly the same like DSD128 file. But after 22K, you could clear see a raising up noise there. Again, don’t worry. That means FINE. We are playing a normal, bit perfect, DSD64 file ~
So since we already have a solid foundation of Wave hardware, with some minor screen light adjustment and battery charging speed need to adjust. What is next?
It would be the software integration, UI… and so on. We will get to that soon.
Next Wave update in 3 weeks (after software team testing)
We will send the boards to the software team this week
Next update will be related to goal number two previously mentioned: the digital stuff. Capacitance. Good jitter... WiFi test and so on.
Thanks for your support!
Larry and Team
PS: Another quick message here, please don’t use my objective and innocent test results of DSD playback to open the debate of “PCM vs DSD which is better” or “DSD64 is really not humanly acceptable or not”... The whole purpose here is to show the backers our milestone and solid process. That is all.
For me, I listen to native DSD music quite often. A lot of them sounds great. But I found if you want to convert DSD back to PCM, you need to use a decent algorithm and fast computing device. Each format should use its best way to decode. That is the principle we have in mind from almost ten years ago.