SMSL M3 with measurements

[bravomail]

SMSL M3 got good measurements on DAC and AMP: https://reference-audio-analyzer.pro/en/report/dac/smsl-m3.php https://reference-audio-analyzer.pro/en/report/amp/smsl-m3.php
Also Stalker has its review on youtube with measurements and DIY mod

In headphone path there are 2 capacitors which drive weaker bass (aka rolled off). DAC has no issues. Capacitors in amp path can be shortened (DIY mod), that solves rolled off bass.
Now on massdrop for ~60. cheap thrills!
If you only need DAC - there is SMSL M2, even cheaper!

 

[KR8NUX]

Someone help decipher the measurements please.

 

[bravomail]

I see SINAD ~112dB from video (DAC portion). For this price - outstanding. Headphone output displays harmonics up to ~92dB.

 

[Slapo]

I can't really decipher what they're talking about, but the measurements look decent from what I can understand from the charts.
I have one, as well as a Sabaj D3 (at my parents' place), Behringer U-Phoria UMC202HD, Lynepaudio A962 and a Syba SD-DAC63094.
I'd say the M3 and the Sabaj D3 sound the best of them and are about on par with each other.
The M3 has an analog volume knob and my unit has severe channel imbalance at the lowest levels. No such issue with the Sabaj, though.
I'll probably add the JDS Labs Atom to work in tandem with the M3 later on.
The Behringer sounds as if a fair bit of detail were lacking unless I crank it up (perhaps high output impedance?) and both the bass and treble seem rolled off compared to either the SMSL or the Sabaj.
The little Syba sounds pretty similar to the Behringer, except I found the roll off less apparent.
The Lynepaudio actually sounds quite nice but the amount of noise on mine is just too high. Curiously enough, when I use it with Blitzwolf BW-BR4, practically I can hear the noise.

Also... this is my first post here. Hello there.

 

[bravomail]

After rewatching video, and checking specs on output power, decided to get it on Massdrop for 60.
Here's quick translation of video:
Headphone output measured.
Very low noise (floor at 120dB or lower)
Very little harmonics (at 103-108db on my eye)
Enough power to drive Senn HD6xx.
Rolled off bass starts at 50Hz, reaches -1dB by 30Hz and about -3dB by 5-10Hz.
Rolled off bass is only on headphone out, not on RCA.
The reason for roll-off are 2 capacitors in signal path, which are used to block small DC (~1 mV) from Dac or Opamp. In stereo - total of 4 capacitors.
He draws schematics in video so everyone can understand.
Capacitors put to fight DC and the noise, caused by it on volume pot (resistor).
If you short-circuit last capacitor (2 in stereo) - roll off is completely gone.
But you will hear some gentle rustle while adjusting your volume.
Also, SMSL M3 is not for IEMs, due to poor balance of channels at low volume.
It is actually will sound its best with harder to drive headphones
Output impedance could be really low because headphone jack is directly connected to some opamp. So if your IEMs are 32 Ohm or higher - you should be fine.

 

[bennetng]

I see SINAD ~108dB from video. For this price - outstanding.

If you meant 0.0004 in 3:15 of the video, it is not SINAD (THD+N). It is THD (without N). Also, RMAA uses -3dBFS as standard while Amir uses 0dBFS.

The Youtube video has a link to this picture:

The measurement interface is EMU0202 and the ADC's official spec is THD+N (1kHz at - 1dBFS, min gain): -103dB (.0007%) and 113dB SNR.
http://www.creative.com/emu/products/product.aspx?category=610&pid=15186

 

[bravomail]

yes, he uses EMU202, and one of his channels broken (red line). Thx for posting pictures! From his pictures - DAC portion (NoLoad) SINAD 112dB. Headphone portion (load 32 Ohm) - Noise at -120db, SINAD -92dB. So I guess good pairing DAC for headphone or speaker amp, and decent (but not great) headphone amp. Will wait to receive this thingy to judge the effect of all these harmonics on sound.

 

[bravomail]

Got it y-day. It is tiny - half palm. I listened to only headphone out, without suggested mod. I will be comparing to my standard stack of Schiit Modi 3/Magni 2. It is little bit lacking in bass and subbass. And there is no such sensational clarity. It sounds better if you power it with extra 5V USB, so that's what I did. It is strong and powerful despite its size, sounds better than tablet's built-in DAC, and much better than Speaka USB stick (Speaka turned out to be powerful, but not good at all). The unit itself comes with 2 USB cables (micro-micro and micro to A), and 6.5mm to 3.5mm plug.
Overall: I have to try the mod to have my verdict.

 

[Theraiden]

Hi all, since i don't speak the language in the video, are these the capacitors to short:

And if so, can i short them with a wire or do i need to use resistors or caps??
Thank you

 

[Theraiden]

Do i also need to short these two? what do i use to short all 4?

 

[JohnYang1997]

The headphone out is shit. Don't bother with it. Dac out is superb for the price.
To get best dac out you need to remove the volume pot and short headphone amp input to ground. Other wise the low frequency have more distortion.

 

[JohnYang1997]

Also to point out that there are capacitors in the signal path on both side of the volume pot. And you don't want to short all capacitors there. Some are bypass capacitors that connects between Voltage rail and ground. Be careful.

 

[Theraiden]

The headphone out is shit. Don't bother with it. Dac out is superb for the price.
To get best dac out you need to remove the volume pot and short headphone amp input to ground. Other wise the low frequency have more distortion.

Well this is the only headphone amp that i have so i need to use it for that. Just want to remove the bass roll-off with this mod. I just need info if those are the 4 caps to short that i point out in the pics i uploaded in this thread, and if so, with what do i short them.

 

[JohnYang1997]

Well this is the only headphone amp that i have so i need to use it for that. Just want to remove the bass roll-off with this mod. I just need info if those are the 4 caps to short that i point out in the pics i uploaded in this thread, and if so, with what do i short them.

It should be the 4 larger ones. But I suggest that you measure the dc offset before plugin in the headphones. I shouldn't exceed 5mv. Sub 1mv is optimal.

 

[JohnYang1997]

The opamp is max97220a. Take a look at datasheet as well.

 

[cestmoi]

Well this is the only headphone amp that i have so i need to use it for that. Just want to remove the bass roll-off with this mod. I just need info if those are the 4 caps to short that i point out in the pics i uploaded in this thread, and if so, with what do i short them.

Did you aply the bass mod to your M3?