SMSL D400 Pro Balanced DAC Review

[Roland68]

Sorry to disturb your rest on a weekend Roland68.
I'd like to ask you something, not only about the D400 PRO, but in general: do you believe that Hi-Fi components DO need a break in time?
I do. I own a Chinese copy of the now discontinued EAR 834P tube Phono preamp since 2017. I've tried new production tubes until I moved to NOS Telefunken ECC83'S (the European equivalent/nomenclatura of US 12AX7) and with either new and NOS tubes, I can positively say that vaccum tubes DO need a break in period.
Around a month and half I changed my ancient B&W DM601's, first series from 1996 (I got their filters changed in 2018) and a new pair of KEF Q-550 and the first impression about their sound couldn't be worse. After a couple of weeks or so and some hours of use, I very much like the sound of these, at least for the kind of music I listen to (Hard Rock, I love Van Halen, movie soundtracks and some Classical an 80's Pop music), and I think the sound of the KEF's is much better, or I least I like them best, that the one of the old B&W. But out of the box I thought their sound was flat and lifeless. Break in I think made the change.

This is not a useful topic here in the forum and I have already written something about it. To put it briefly, there is a billion-dollar industry worldwide for pre-aged components, which is nothing other than burn-in. These are used in industry, the military, aviation, aerospace, measurement technology, medicine, high-availability electronics, etc. The reason is that components do not have stable operating points at the beginning of their service life. This does not necessarily have to have audible effects, but it can.
You can try this with your tubes. Buy 2 new sets, listen to both briefly to see if they are the same. Put one set aside for a year and then compare again.
With loudspeakers you have 2 to 3 moving materials whose properties change through movement. There are enough studies in the industry on this topic in relation to membranes and changes over the service life. The same and similar materials, the same and similar functions. Here too, this does not have to have audible effects, but it can.

 

[Kiko1974]

This is not a useful topic here in the forum and I have already written something about it. To put it briefly, there is a billion-dollar industry worldwide for pre-aged components, which is nothing other than burn-in. These are used in industry, the military, aviation, aerospace, measurement technology, medicine, high-availability electronics, etc. The reason is that components do not have stable operating points at the beginning of their service life. This does not necessarily have to have audible effects, but it can.
You can try this with your tubes. Buy 2 new sets, listen to both briefly to see if they are the same. Put one set aside for a year and then compare again.
With loudspeakers you have 2 to 3 moving materials whose properties change through movement. There are enough studies in the industry on this topic in relation to membranes and changes over the service life. The same and similar materials, the same and similar functions. Here too, this does not have to have audible effects, but it can.

Thanks. I couldn't agree with you more.
I think a device that has a number of components, resistors, capacitores, IC's, power supplies etc DO need a time for this components to settle in and work together properly as a whole.
The test you sugests with tube,s I'd done It. Get six Telefunken ECC83 (my Phono uses three of these), tests them all, combining the six of them together to check all of them work properly. I then left three on my Phono preamp for daily use and put the other six aside for around six months. After this time, I swapped the tubes and put in the set of the three unused ECC83'S. The unused ECC83'S sounded different, one could say they sounded worse, than the three that had over six months of use.
So I think break in IS reality and a fact, just my 0.03$.

 

[staticV3]

I think a device that has a number of components, resistors, capacitores, IC's, power supplies etc DO need a time for this components to settle in and work together properly as a whole.

Facts and evidence do not support this.

 

[Kiko1974]

Facts and evidence do not support this.

Please, provide those facts.

 

[staticV3]

Please, provide those facts.

MEASUREMENTS: Does "Burn-In" / "Break-In" Happen for Audio DACs?

A blog for audiophiles about more objective topics. Measurements of audio gear. Reasonable, realistic, no snakeoil assessment of sound, and equipment.

archimago.blogspot.com

DAC burn-in/break-in? My Gustard X16 measurements

This is a post copied from my other thread at https://www.audiosciencereview.com/forum/index.php?threads/phase-shift-and-echo-trails-length-illusion.20618/post-684254. When I first got my X16 into my stereo setup, my first impression was E30 have better highs. Because I did voltages...

www.audiosciencereview.com

Equipment Performance During Warm Up

@ENIGMA raised an interesting question regarding the performance of DACs during warm up and their long term stability. So, I am performing a test using a Topping DX7pro DAC to investigate. The DAC is playing a 1kHz tone at full scale and an FFT is taken at time periods to measure its signal level...

www.stereonet.com

 

[Kiko1974]

Another question I have regarding the combination of AK4191 plus AK4499EX is oversampling of DSD.
With DACS using this chipset there's a nondefeateble function called Sound Color with four flavours of It.
Sound Color 1 &2 state they make the D/A converter work at 5.6 MHz, and Sound Color 3 & 4 make the Converter work at 11.2 MHz. That's 128 x and 256 x oversampling.
That works with DSD too even if the "fixed outputs DSD un processed" is on.
Does this mean that by oversampling DSD to x128 or x256 gets DSD ultrasonic Noise shifted far out of the audio range further than if DSD was played without oversampling?

 

[Scytales]

To the best of my knowledge, I think not, because the spectrum of DSD64 in the frequency domain is "backed in the cake" and oversampling shouldn't modify it just by itself, just as oversample PCM does not change the frequency spectrum in the pass band just by itself. To change the HF noise spectrum of DSD64 requires a low pass filter. I may be stand corrected on this.

That being said, those two AKM chips are very complex and incorporate comprehensive options designers can choose from. From their respective datasheets, if I understand them correctly, it is possible to defeat any re-modulation (by a multilevel sigma-delta modulator) of the original DSD sampling rate, but DSD, whatever the original sampling rate is (from DSD64 to DSD512 in the AK4399 and DSD64 to DSD1024 in the AK4191) always passes through a digital low pass filter whose corner frequency is selectable and sampling rate dependant. This choice of low-pass filter is what is called "sound color selection" in the AK4399 datasheet. So, I assume that whatever choice has been made by the designer of left to the user, the HF noise content of DSD64 will be tamed downed by the chip digital low-pass filter if this HF noise is what bother you.

 

[Kiko1974]

One more surprised with the D400 PRO, than may also extend to most SMSL DAC's: the jitter reduction circuitry.
The SMSL D400 PRO, using the Chinese HDMI audio extractor that Amir revised several months ago, I get DSD channels inverted vía I2S output/input. This DAC has on the configuration menu and option to correct this, It actually has two, one for "general" I²S and a second one for DSD over I²S to invert channels in the case this happens because of different pin out configuration on the I²S/HDMI port. Well, this feature DOES work on the DO300 EX but It doesn't on the D400 PRO. I get, with my Chinese HDMI audio extractor DSD channels inverted.
So the only option to get the right DSD Channels is using DSD over PCM vía either S/PDIF of TosLink. At first I used the S/PDIF output of the Chinese HDMI audio extractor and got great results, sound was great.
But I wanted to have the S/PDIF output of my Sony UBP X-800 M2 player, which is my main digital source (the other one is an LG OLED TV set), connected directly to the S/PDIF input of the D400 PRO input, so the only option was to try something I was very reluctant: connecting the TosLink output of the Chinese HDMI audio extractor to the TosLink input of the D400 PRO.
I've never liked TosLink connection, the last time I used It was to Connect a Marantz CD67 CD player to a Sony Mini Disc deck, and that was back in the late 1990's.
TosLink is well known to be very jitter prone and be problematic with resolutions over 96/24.
I ended up connecting the TosLink output of the Chinese HDMI audio extractor to the TosLink input of the D400 PRO using an inexpensive KabelDirekt optical cable I had around with the right length I needed.
To my surprise the TosLink input on the D400 PRO sounds great, not only with DSD as DoP and also with HiRes PCM. I've never heard a TosLink connection sounding so good.
I guess this is because the jitter reduction circuitry on the D400 PRO (and other SMSL models), the Second order PLL and the "self developed CK-03 master clock". It seems to performs admirably well as jitter has always been the Aquilles Heel of TosLink connection.

 

[Kiko1974]

I contacted SMSL and explained them about the issue with the I²S connection and the configuration menu having a setting to inverse I²S channels, both for a general purpose and an specific one for DSD, and channel invertion for DSD doesn't work.
They sent me a firmware update that has two steps, first what It seems like a driver (I had XMOS driver installed already on my laptop, which I downloaded from SMSL's website), and a second step that seems to be the actual firmware update. The file that does the update doesn't work, It doesn't execute. I asked them for further instructions to guide me with the process and to send me the update file again just in case the first one is corrupted, but I doubt that as It was extracted with no problems. They did, I tried all the process again WITH THE ANTIVIRUS OFF, and same again, I'm able to install the same step, what It looks like a driver, but when I get to the second step, the file I have to execute, It doesn't work.
I've told them why they don't upload the update to their website, as they've done with some of their other products. But after two weeks trying to update my D400 PRO the update is not up on their website. I suspect this firmware update they sent me is an half cooked one.

 

[Bogrum]

Hello everyone! Please advise. I connected this DAC to a power amplifier (without a preamplifier). Does the sound quality drop when adjusting the volume on the DAC?
Message created with Google translate, sorry for the grammar.

 

[staticV3]

Hello everyone! Please advise. I connected this DAC to a power amplifier (without a preamplifier). Does the sound quality drop when adjusting the volume on the DAC?
Message created with Google translate, sorry for the grammar.

Hi @Bogrum! Welcome to ASR.

If you can hear the DAC's noise floor as hiss coming from your speakers, when listening from your usual listening position, then you're sacrificing sound quality and may be better served by an analog preamp between DAC and Amp.

If you cannot hear any hiss, then you're not losing sound quality, no matter how heavily you use the DAC's digital volume control.