SMSL DO400 Fully Balanced Audio Decoder & Headphone Amplifier

[nanook]

Edit:
Corrected comment for #8, Low Dispersion
Dirac measurement and spectrum at Fs=44100

Updated slides for PCM filter options.
According to my measurements the description of the PCM filters in the menu of the DO400 is wrong for several of the filter settings.
Since people experiment with these filter options and spend time and effort to hear differences, the information should be reliable.

--> Can someone confirm the measurement in the time domain (Dirac pulse)?

If my measurements are confirmed I would ask SMSL to issue a corrected FW.

 

[MicrosPL]

I tried, but the executable "ispV2.4.exe" does not start. It seems to start (visible in the task manager for a second or so.), but then nothing happens..
Windows defender does not complain, nor does anything else.
--> Has anyone an idea?

---------------- System ------------
Edition Windows 10 Pro
Version 22H2
Installiert am ‎04.‎12.‎2021
Betriebssystembuild 19045.4412
Leistung Windows Feature Experience Pack 1000.19056.1000.0

I have no idea. I suggest you try on another computer. In my case, the application ran correctly on a third computer with Windows 10 that had not been updated for 2 years.

 

[MicrosPL]

Updated slides for PCM filter options.
According to my measurements the description of the PCM filters in the menu of the DO400 is wrong for several of the filter settings.
Since people experiment with these filter options and spend time and effort to hear differences, the information should be reliable.

--> Can someone confirm the measurement in the time domain (Dirac pulse)?

If my measurements are confirmed I would ask SMSL to issue a corrected FW.

Interesting thing. Did you perform these measurements on firmware version Va3?

 

[RedEyeNinja]

I have a new set of sjy horizons connected via xlr to my DO400 and when selecting output to "Balanced", I get no sound. Is there something I'm doing wrong? I get sound when using "Headphones" as output.

 

[nanook]

Interesting thing. Did you perform these measurements on firmware version Va3?

Yes, I finally got the FW loader working and I even did a separate "verify" run (without writing the new FW) and I got a match.
-> I'm quite confident it's the V3 version.

To me it looks like the filters might be mixed up in the same manner as for D400ES. #6 (pink curve) e.g. is definitely not a fast roll-off.

SMSL D400ES DAC Review

This is a review and detailed measurements of the SMSL D400ES Balanced Stereo DAC with Bluetooth support. It was sent to me by the company and costs US $800. The D400ES is quite stylish especially if you look at it an angle where it exposes the black heatsinks. Alas, the rotary control is not...

www.audiosciencereview.com

For the D-6s it looks also quite different compared to what the manual says. But here it's just numbers, not names...
I will post that measurement when I find some time.

 

[nanook]

This is indeed weird.
For my DO400 this works as expected.

I did not try to activate XLR and RCA separately, but "all line out" and "headphone" was fine.

I have a new set of sjy horizons connected via xlr to my DO400 and when selecting output to "Balanced", I get no sound. Is there something I'm doing wrong? I get sound when using "Headphones" as output.

 

[MicrosPL]

Updated slides for PCM filter options.
According to my measurements the description of the PCM filters in the menu of the DO400 is wrong for several of the filter settings.
Since people experiment with these filter options and spend time and effort to hear differences, the information should be reliable.

--> Can someone confirm the measurement in the time domain (Dirac pulse)?

If my measurements are confirmed I would ask SMSL to issue a corrected FW.

@amirm are you able to confirm this measurements in the time domain? Reporting this to the manufacturer seems to be a very valuable idea.

 

[josiah]

Can anyone point me to headphone amp measurements? I just want to make sure their is the same or less noise than my current DX3 Pro+.

 

[Longfellow78]

Updated slides for PCM filter options.
According to my measurements the description of the PCM filters in the menu of the DO400 is wrong for several of the filter settings.
Since people experiment with these filter options and spend time and effort to hear differences, the information should be reliable.

--> Can someone confirm the measurement in the time domain (Dirac pulse)?

If my measurements are confirmed I would ask SMSL to issue a corrected FW.

Hello. I have this amp and was not aware this was an issue. I never messed with the PCM filters and left it on standard but was told that linear fast was preferred. however according to your post this might now be correct anyway. Any advise for what to set it to until/if they create a new firmware? I listen to EVERYthing. Thanks.

 

[nanook]

Any advise for what to set it to until/if they create a new firmware?

Looking at my measurements I would choose #3 (Menu: "Apodizing") which is steep and rolls-off early, so it provides good attenuation at Fs. My guess is that this actually is the one ESS labelled "Linear phase fast roll-off" in their datasheet. It is the only steep filter that rolls-off earlier than all of the others.

In case this one rolls off too early to your taste, #4 (Menu: "Linear Fast") would be an alternative. It also rolls off steep but at a bit higher frequency.

If you prefer minimum phase filters (no pre-ringing, more post ringing) #2 (Menu: "Minimum Phase) or #7 (Menu: "Minimum Slow") would be an option. They provide a steep roll-off and similar attenuation as #4

The attenuation at Fs is not really readable in my measurements due to the large frequency span and the log scale. I was hoping to identify the filters comparing them to the frequency- and impulse- response given in the datasheet, but some of them appear to be quite similar.
What's also weird is that many of the filters they show in the datasheet have a steep roll-off down to -60dB only, whereas I measured a steep roll-off down to ca. -100dB.
(I'm referring to the datasheet version ES9039MPRO_ES9039PRO_v0.2.1.pdf)

I'm actually not optimistic they will build new firmware...

 

[RedEyeNinja]

What do you guys think about feeding xlr from the DO400 to a SP400?

 

[Roland68]

What do you guys think about feeding xlr from the DO400 to a SP400?

What should we think of this?
It is the best way to connect the two devices.

 

[nanook]

What do you guys think about feeding xlr from the DO400 to a SP400?

XLR is the best way in case you have these on both sides.

You want to use the (analog) volume control of the SP400 for some amplifier or active speakers? The DO400 does have a quite capable HPA.

 

[RedEyeNinja]

XLR is the best way in case you have these on both sides.

You want to use the (analog) volume control of the SP400 for some amplifier or active speakers? The DO400 does have a quite capable HPA.

I mean... On paper the SP400 has double the power output of the DO400 and I wonder what you guys think of the additional headroom it may provide to harder to drive magnetic planars, which I am listening to on the DO400, with high gain between -10 to - 5 dB.

 

[nanook]

Ok. .... I'm actually having the contrary problem with my 12 Ohm In-Ears even though they are connected to the single-ended jack- socket. I have to attenuate the DO400 a lot even with low-gain setting.

In the end 2x power just makes 3dB more SPL, so this will probably not make a huge difference.
But I agree, the SP400 is a high performance stand-alone HPA and not an add-on like the one in the DO400 (which is quite powerful already), so I wouldn't wonder if the SP400 could handle a difficult load with more ease compared to the DO400.
It's a lot of money in the end - your decision.

--> In case you give it a try, let us know how the SP400 compares to the DO400

 

[Roland68]

I mean... On paper the SP400 has double the power output of the DO400 and I wonder what you guys think of the additional headroom it may provide to harder to drive magnetic planars, which I am listening to on the DO400, with high gain between -10 to - 5 dB.

The SP400 is not more powerful than the HPA in the DO400.
The DO400 is identical to the Loxjie D40 Pro, which Amirm has already tested, just like the SP400. You can compare the measured power in the two tests. Both are just over 4 watts at maximum.
The DO400 also has more powerful power supplies installed.
I don't think the SP400 would give you an advantage, not even in terms of sound.
I have both the SP400 and the DO400 here. When I get the chance, I'll compare them with the HE6SE V2 in the next few days.

The next more powerful HPA would be the Topping L70 with around 7 watts.

 

[nanook]

I have both the SP400 and the DO400 here. When I get the chance, I'll compare them with the HE6SE V2 in the next few days.

@Roland68 Did you have a chance to compare these?

According to Amir's measurements, the D40 Pro HPA starts to have some distortion for load impedance below 300 Ohms. At 12 Ohms they are still below ca. 95dB - clearly below audibility to my opinion.
Technically this surely is avoidable with more care given to the PCB artwork.

 

[Roland68]

@Roland68 Did you have a chance to compare these?

According to Amir's measurements, the D40 Pro HPA starts to have some distortion for load impedance below 300 Ohms. At 12 Ohms they are still below ca. 95dB - clearly below audibility to my opinion.
Technically this surely is avoidable with more care given to the PCB artwork.

Unfortunately, I won't be able to do it until the weekend and will post it then.
I hadn't seen the distortion thing yet, but now I'm influenced by you and will hear this distortion all the time....

But it's not the same board and it wouldn't be the first time that Loxjie has had worse readings due to the layout or parts used.

 

[arrow0309]

Looking at my measurements I would choose #3 (Menu: "Apodizing") which is steep and rolls-off early, so it provides good attenuation at Fs. My guess is that this actually is the one ESS labelled "Linear phase fast roll-off" in their datasheet. It is the only steep filter that rolls-off earlier than all of the others.

In case this one rolls off too early to your taste, #4 (Menu: "Linear Fast") would be an alternative. It also rolls off steep but at a bit higher frequency.

If you prefer minimum phase filters (no pre-ringing, more post ringing) #2 (Menu: "Minimum Phase) or #7 (Menu: "Minimum Slow") would be an option. They provide a steep roll-off and similar attenuation as #4

The attenuation at Fs is not really readable in my measurements due to the large frequency span and the log scale. I was hoping to identify the filters comparing them to the frequency- and impulse- response given in the datasheet, but some of them appear to be quite similar.
What's also weird is that many of the filters they show in the datasheet have a steep roll-off down to -60dB only, whereas I measured a steep roll-off down to ca. -100dB.
(I'm referring to the datasheet version ES9039MPRO_ES9039PRO_v0.2.1.pdf)

I'm actually not optimistic they will build new firmware...

Hi I have this dac for a few days only, just tried now to switch to a PCM filter (it was on Filter off) so I used the Apodising (also tried the second and the Linear Fast).
The volume lowers though, I'm on low gain with the Ananda v3.

BTW.
Tried to apply the firmware downloaded a couple of days from their site but it won't start. Power off, keep pressing the volume knob for another 5 sec (or less, or more), it won't show connected on the utility window.

 

[nanook]

Hi I have this dac for a few days only, just tried now to switch to a PCM filter (it was on Filter off) so I used the Apodising (also tried the second and the Linear Fast).
The volume lowers though, I'm on low gain with the Ananda v3.

Filter off is only to be used with heavy upsampling upstream in software. If you look at the frequency response graphs when measured with 48kS/s you get an impression why "filter off" does not make sense without the adequate stream.

Tried to apply the firmware downloaded a couple of days from their site but it won't start. Power off, keep pressing the volume knob for another 5 sec (or less, or more), it won't show connected on the utility window.

For some reason the v3 firmware has disappeared from the SMSL website:

SMSL Audio Official -Professional audio product manufacturer

Foshan ShuangMuSanLin electronics Co., LTD. founded in 2009 which located in Shenzhen, China. And our branch company VMV Technology(HK) Company Limited registered in HK in 2013. Our company is specialized in the audio DAC, stereo headphone amplifier, power amplifier, and with own R&D...

www.smsl-audio.com

Either this is good news (are they preparing a v4?) or what's the idea of removing the latest firmware.
(I did have problems with the loader that did depend on which RAR unpacking program I was using (https://audiosciencereview.com/foru...ecoder-headphone-amplifier.47766/post-1980330). I reported this to SMSL and suggested to use the far more common zip packing format in future.
Maybe there's something on the way?)