• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

SMSL DO400 Fully Balanced Audio Decoder & Headphone Amplifier

Longfellow78

Member
Joined
Dec 18, 2023
Messages
27
Likes
0
Is this the best value right now? Struggling between this, the Loxjie D40 Pro, Fiio K9 and the Topping DX5.
I actually have the loxjie, not the smsl. The loxjie is the best value on the market if you can get it cheaper than than do400 and don't need the couple extra features of the do400, which apparently are the pre amp feature and that's about it. This thread states that the d40 pro has 9 op amps and the do400 has 11 but I saw another thread that said they both had 11 and the only difference was the brand of op amps. Don't know what's true. I personally think the loxjie is aesthetically much nicer and more retro/industrial and it also has physical buttons to control features without needing to use a remote or dial interface. The fiio and topping are overpriced vs the smsl and joxjie although the K9 has lots and lots of features but I believe it sounds worse.
 

Longfellow78

Member
Joined
Dec 18, 2023
Messages
27
Likes
0
Oh. I think do400 has Bluetooth 5.1 instead of 5.0 on loxjie which is no practical difference. I also read people saying something about the do400 being "upgradeable". No idea what or how that means.
 

iTuner

Member
Joined
Nov 17, 2023
Messages
6
Likes
4
I actually have the loxjie, not the smsl. The loxjie is the best value on the market if you can get it cheaper than than do400 and don't need the couple extra features of the do400, which apparently are the pre amp feature and that's about it. This thread states that the d40 pro has 9 op amps and the do400 has 11 but I saw another thread that said they both had 11 and the only difference was the brand of op amps. Don't know what's true. I personally think the loxjie is aesthetically much nicer and more retro/industrial and it also has physical buttons to control features without needing to use a remote or dial interface. The fiio and topping are overpriced vs the smsl and joxjie although the K9 has lots and lots of features but I believe it sounds worse.
DO400 and D40 Pro differ in capacitors, display, housings and firmware.
Both devices can be updated with firmware.

The differences are mostly in the interface.
However, the DO 400 can also be controlled from the front panel using an encoder.
The DO 400 can use both line outputs together.
 

Longfellow78

Member
Joined
Dec 18, 2023
Messages
27
Likes
0
DO400 and D40 Pro differ in capacitors, display, housings and firmware.
Both devices can be updated with firmware.

The differences are mostly in the interface.
However, the DO 400 can also be controlled from the front panel using an encoder.
The DO 400 can use both line outputs together.
Thank you for this information. You are right it was the capacitors of different brands not the op amps. Does different capacitors make any practical difference? Also could you tell me please I read that the do400 can act as a preamp and the d40 pro can't. Is that true? I am very new to all this and trying to underatand. Thank you.
 

iTuner

Member
Joined
Nov 17, 2023
Messages
6
Likes
4
The DO 400 uses higher quality capacitors, but I don't know how much this affects the sound of the device.
D40Pro always uses preamp mode. That is, the volume control is always on.
And I don’t know if they added the ability to use two line outputs at once for the D40Pro. There is no such option in the manual.
It is very convenient to be able to connect two amplifiers or an amplifier/active speakers plus subwoofer. The DO400 has such an option. And it is possible to fix the volume on the line outputs
 
Last edited:

David_M

Senior Member
Joined
Sep 10, 2019
Messages
300
Likes
191
Please can someone assist regarding the firmware update. Instructions reference using a "micro USB" where/what/how is this port please? I only see the normal USB B socket? Thanks.
Yeah, that micro USB thing threw me for a loop until i chanced to ignore it.
 

Longfellow78

Member
Joined
Dec 18, 2023
Messages
27
Likes
0
The DO 400 uses higher quality capacitors, but I don't know how much this affects the sound of the device.
D40Pro always uses preamp mode. That is, the volume control is always on.
And I don’t know if they added the ability to use two line outputs at once for the D40Pro. There is no such option in the manual.
It is very convenient to be able to connect two amplifiers or an amplifier/active speakers plus subwoofer. The DO400 has such an option. And it is possible to fix the volume on the line outputs
Thanks a lot. I visited my dad this weekend and found he had a mint condition quad 405 power amp. I remember it from being a kid but didn't know what it was. I was wondering if it could pair with the loxjie!
 

sailor2005

Active Member
Joined
Oct 8, 2020
Messages
121
Likes
168
Thanks a lot. I visited my dad this weekend and found he had a mint condition quad 405 power amp. I remember it from being a kid but didn't know what it was. I was wondering if it could pair with the loxjie!
You can. As long as you can find a DIN to RCA cable.
 

Longfellow78

Member
Joined
Dec 18, 2023
Messages
27
Likes
0
Can someone please tell me, if I were to connect this device to a dap via Bluetooth, and play a lossless flac file from the sd card or streamed from a media server, would the playback of the file on the dac be identical to being connected via coaxial cable? I.e. Is the Bluetooth transmission of the file compressed or lossless? Thank you.
 

derKoekje

Member
Joined
Jun 1, 2022
Messages
33
Likes
4
Can someone please tell me, if I were to connect this device to a dap via Bluetooth, and play a lossless flac file from the sd card or streamed from a media server, would the playback of the file on the dac be identical to being connected via coaxial cable? I.e. Is the Bluetooth transmission of the file compressed or lossless? Thank you.
Compressed doesn't mean lossless or lossy. It just means compressed. Bluetooth is lossy so no, the file wouldn't be 'the same'. You would want to connect some kind of streamer for that instead.
 

Longfellow78

Member
Joined
Dec 18, 2023
Messages
27
Likes
0
DO400 and D40 Pro differ in capacitors, display, housings and firmware.
Both devices can be updated with firmware.

The differences are mostly in the interface.
However, the DO 400 can also be controlled from the front panel using an encoder.
The DO 400 can use both line outputs together.
Thanks. I actually found the do400 on sale for only £15 more than the d40 pro so I sent the d40 back and ordered the do400. I think the loxjie looks cooler and more retro but the do400 was the better deal. Can I ask you about the PCM filters please? Are these worth using? I saw a reviewer to use the no filter option? Others saying use "1" or "3". I underatabd what they do, but wonder why they exist and if it's better to turn it off. Thanks.
 

pundel

Member
Joined
Sep 16, 2023
Messages
43
Likes
24
on different smsl devices, different filter settings, like most people, I use without a filter and the color of the sound standart all this from device to device that is, different quality and different settings
 

NexusOne

Member
Joined
Dec 20, 2021
Messages
63
Likes
7
Hello,

I am very interested in the DO400 and I have some questions. I wanted to buy a dac and amp but I think an all in one solution with a remote is better.

- Do you think it is strong enough for the HEK Stealth? Does it limit the sound of the headphone?
- Do you know better alternatives? Maybe Topping Dx9 or Aune S9c Pro?
 

David_M

Senior Member
Joined
Sep 10, 2019
Messages
300
Likes
191
Hello,

I am very interested in the DO400 and I have some questions. I wanted to buy a dac and amp but I think an all in one solution with a remote is better.

- Do you think it is strong enough for the HEK Stealth? Does it limit the sound of the headphone?
- Do you know better alternatives? Maybe Topping Dx9 or Aune S9c Pro?
1. What is the impedance of your headphones? The DO400 HA provides 6 Watts per channel into 32ohms at ultralow distortion. It can drive all headphones out there with ease.
2. The Do400 sounds excellent to me and the change in my setup was obvious. Hard to find a credible competitor at their price point that uses the latest ES9039 dac and USB formats.
 

doctor55

New Member
Joined
Jan 31, 2024
Messages
1
Likes
1
Good morning everyone, I recently bought the DO400 and I connected to the outputs in both balanced and unbalanced. I expected that in balanced the volume would be louder but to my surprise I did not notice any difference. any explanation? thank
 

David_M

Senior Member
Joined
Sep 10, 2019
Messages
300
Likes
191
Good morning everyone, I recently bought the DO400 and I connected to the outputs in both balanced and unbalanced. I expected that in balanced the volume would be louder but to my surprise I did not notice any difference. any explanation? thank
That explains why the THDN specs don't specify if they are measured from balanced or unbalanced outputs. But many audio devices have balanced outputs for mechanical convenience only.
 

sailor2005

Active Member
Joined
Oct 8, 2020
Messages
121
Likes
168
That explains why the THDN specs don't specify if they are measured from balanced or unbalanced outputs. But many audio devices have balanced outputs for mechanical convenience only.
Did you check the SMSL DO400 page? THD+N measurements are listed separately for XLR and RCA outputs. The person claiming the output was the same does not say what device the DAC was connected to. Some amps might set their input sensitivity according to the connection. Also we don't know the behavior of the connected device when using both XLR and RCA at the same time because we don't have any idea as to which amp or preamp is connected to the SMSL.

 

NexusOne

Member
Joined
Dec 20, 2021
Messages
63
Likes
7
But it is truly balanced? Do you think an upgrade to the Topping DX9 makes sense?
 

David_M

Senior Member
Joined
Sep 10, 2019
Messages
300
Likes
191
Did you check the SMSL DO400 page? THD+N measurements are listed separately for XLR and RCA outputs. The person claiming the output was the same does not say what device the DAC was connected to. Some amps might set their input sensitivity according to the connection. Also we don't know the behavior of the connected device when using both XLR and RCA at the same time because we don't have any idea as to which amp or preamp is connected to the SMSL.

Was thinking of HA specs, which aren't clear if they are for balanced or unbalanced HA output.
 
Top Bottom