• 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 M400 Balanced USB MQA DAC Review

mrjayviper

Member
Joined
Jun 27, 2022
Messages
85
Likes
2
Q1 the signal/volume gets lower once the signal gets above 20000hz some filters the volume falls away very quickly at high levels. Different filter settings adjust how quickly.

if that's the case. shouldn't 3, 4 and 5 be the "ideal" situation where there's no loss of volume as the frequency goes up? Thanks again
 

Mr.Ian

Member
Joined
Oct 12, 2021
Messages
18
Likes
11
Guess it depends on whether you can hear/feel/sense sound at these frequencies and if there is any usable musical information there. I suspect in most cases not so the steep fall off, brick wall filters that remove unnecessary noise might work better. But with switchable filters you have the choice
 

gvl

Major Contributor
Joined
Mar 16, 2018
Messages
3,427
Likes
3,982
Location
SoCal
if that's the case. shouldn't 3, 4 and 5 be the "ideal" situation where there's no loss of volume as the frequency goes up? Thanks again

No. The ideal filter will be vertical drop from 0dB to infinity at 22.05kHz as everything above that frequency cannot be in a digital signal at 44.1kHz sampling (lookup Nyquist theorem). This is difficult to achieve in practice, so the typical set of available filters represent various approximations to the ideal one with different tradeoffs.
 
Last edited:

Mr.Ian

Member
Joined
Oct 12, 2021
Messages
18
Likes
11
And for example some audio recording techniques for example only Sony SBM move noise ti higher frequencies ti make the core human hearing band better
 

gvl

Major Contributor
Joined
Mar 16, 2018
Messages
3,427
Likes
3,982
Location
SoCal
Of course that doesn't hold true with, 48k 96k 192k etc etc

The Nyquist theorem certainly holds true, but the desired filter cutoff frequency naturally moves up with the increased sampling rate.

As for noise shaping, I don’t think it has any bearing on the ideal filter.
 

comeli

New Member
Joined
Jul 27, 2022
Messages
1
Likes
0
Olá a todos, comprei recentemente um SMSL M400 e me deparei com ruídos no som, usando windows 11/10 na frequência de 384000khz
Alguém já teve esse tipo de problema. HW ver: 1.5 SW ver: 1.2 usb ver: 2.06 Usei o firmware disoinivel aqui e nada mudou. Mas o bluethooth parou de funcionar, conecta no aparelho mas não sai som.
 

mete

Member
Joined
Dec 31, 2021
Messages
11
Likes
1
+1 I would like confirmation from @SMSL-Mandy as well since I did a small trace and the I2S signal (from the HDMI connector) enters the Altera IC which should be doing the re-clocking. Maybe it's just for signal switching purposes, but maybe not.

Is this confirmed ?
 

formdissolve

Senior Member
Forum Donor
Joined
Jul 19, 2019
Messages
363
Likes
309
Location
USA
Does anyone know if the optical functionality has issues with LG tv's and some DVD/CD players like most new Topping DACs do?

Note: The issue with Topping DACs over optical is that it has frequent dropouts which render as clicks in playback.
 

sq225917

Major Contributor
Joined
Jun 23, 2019
Messages
1,361
Likes
1,613
The optical outs of many tv's are so bad dacs don't have the bandwidth to correct it. Some do.
 

formdissolve

Senior Member
Forum Donor
Joined
Jul 19, 2019
Messages
363
Likes
309
Location
USA
The optical outs of many tv's are so bad dacs don't have the bandwidth to correct it. Some do.
True, but I have basically zero issues when the optical from the TV is connected to my old Schiit Modi 3. Meanwhile, the Topping E50 I have drops out all the time over optical. The coax and USB have zero issues though.

My HDMI switch/extractor unfortunately only has optical out
 
Last edited:

FrankH72

New Member
Joined
Oct 8, 2022
Messages
1
Likes
0
On a more general topic: what audio measurement software/hardware is used here? As a newbie to the forum...
 

HiFindingnemo

Member
Joined
Feb 25, 2022
Messages
19
Likes
21
Hey all - I'm looking into buying a used SMSL M400 or D1se. Do folks still like their M400s here a few years later? Any issues to be aware of with MQA playback or quality control? Anyone have experience with both the M400 and D1se and care to share your impressions?
 

HiFindingnemo

Member
Joined
Feb 25, 2022
Messages
19
Likes
21
Well 'Ok' but ShiZo is talking about the original v1 M400 which showed a non-oversampling kind of 6db+ roll-off on the RCA output (a deliberate effect SMSL first said but then they fixed it, new units have a sticker that indicates that).
Hey - I'm looking into purchasing a used M400. What does the sticker look like/where is it located that indicates it's a newer unit with fixed rca?
 

Veri

Master Contributor
Joined
Feb 6, 2018
Messages
9,596
Likes
12,036
Hey - I'm looking into purchasing a used M400. What does the sticker look like/where is it located that indicates it's a newer unit with fixed rca?
It's a long time ago but the box had a sticker like 'Fixed' or 'New version' or something very clear like that.
 

formdissolve

Senior Member
Forum Donor
Joined
Jul 19, 2019
Messages
363
Likes
309
Location
USA
As far as I'm aware, all units shipped had the RCA fix. If you go to their site there is NO new firmware to download, so there would be no way for people to update. I think the RCA issue was noticed on pre-released units?

Edit: I just checked the box (I bought one new a month ago), and I see no reference to "new" or "fixed" on the box
 
Last edited:

Veri

Master Contributor
Joined
Feb 6, 2018
Messages
9,596
Likes
12,036
As far as I'm aware, all units shipped had the RCA fix. If you go to their site there is NO new firmware to download, so there would be no way for people to update. I think the RCA issue was noticed on pre-released units?
That's just wrong, the first batch or batches had a problem that was revised in hardware, not firmware. No one mentioned firmware. Anyway, it's all here in this thread in the first so many pages, just have to read through it..

 

formdissolve

Senior Member
Forum Donor
Joined
Jul 19, 2019
Messages
363
Likes
309
Location
USA
That's just wrong, the first batch or batches had a problem that was revised in hardware, not firmware. No one mentioned firmware. Anyway, it's all here in this thread in the first so many pages, just have to read through it..

Well, my friend Vincent, have a good time trying to find very early hardware with any RCA problems, because it most likely doesn't exist in the wild anymore - if it does, it will be updated, or returned to the manufacturer. You do know that hardware on these units can be updated, right? And that there is no firmware update, hence - all units shipped are good? No one should worry. Time to move on.
 

Veri

Master Contributor
Joined
Feb 6, 2018
Messages
9,596
Likes
12,036
Well, my friend Vincent, have a good time trying to find very early hardware with any RCA problems, because it most likely doesn't exist in the wild anymore - if it does, it will be updated, or returned to the manufacturer. You do know that hardware on these units can be updated, right? And that there is no firmware update, hence - all units shipped are good?
Why are you so stubborn? There was at least one but probably multiple early batches that show a roll-off problem on the RCA outputs, there is no way you can assume "all units shipped" were good. That's just wishful thinking. @HiFindingnemo mentioned wanting to buy used. So I would at least be cautious of early serial numbers. That's just rational thinking.
 

sq225917

Major Contributor
Joined
Jun 23, 2019
Messages
1,361
Likes
1,613
Just so wrong headed. That units shipped before the fix, reached loads of places including many retailers. It was likely many hundreds if not 1000's of units. It wasn't just the first shipment.

Certainly they reached the uk via Amazon and euro via Audiphonics.

Please don't give wrong Information out. The first few months production was affected, smsl could provide numbers if they wanted.

That said, local hifi buddy has one, it's not an issue.
 
Top Bottom