strange SMSL M500 high 3rd harmonic

[Paulo83]

I have a device that has an upgraded firmware. I measured the output and the issue is gone.

Out of interest, did you receive an updated device or did you perform the update yourself?

 

[fluufy]

Could some one, please, clarify if putting the DAC before an Active buffer preamp (So at level under half) does remove the 3rd harmonic problem or when you re-amplyfy the harmonic distortion even being low distortion at low level gets re amplified externally (gets back in the signal) ? I mean if it is solved that way may be a temporary solution for european users till we get repair shop under our customs borders. I think it kind of solves the glare in my headphones. , Preamplifying externally, But not sure if i´m placeboing myself and dont have the proper equipment to measure it. I know the active preamp may introduce its own distortion, but i wanted to know if the odd harmonic in the original signal is only there when DACs digital level is high.

Way way back in this thread somewhere near the beginning of time I recall seeing that the issue is reduced at lower DAC output. 30 or 32 I think it was. A clean amp with enough grunt will cover that, both my Schiit Heresy and SMSL SH-9 will happily run my Hifiman Sundaras this way even with eq. But there is not much headroom, so if you have very hungry headphones you might want more.

 

[JSmith]

I received what is clearly a previously used unit as it is missing caps and has minor marks. :|

Shit... that 'aint right at all. They supposed to be updating your unit and returning it to you, not sending out a refurb. I'd be asking sternly why this has occurred.



JSmith

 

[MusicNBeer]

Could some one, please, clarify if putting the DAC before an Active buffer preamp (So at level under half) does remove the 3rd harmonic problem or when you re-amplyfy the harmonic distortion even being low distortion at low level gets re amplified externally (gets back in the signal) ? I mean if it is solved that way may be a temporary solution for european users till we get repair shop under our customs borders. I think it kind of solves the glare in my headphones. , Preamplifying externally, But not sure if i´m placeboing myself and dont have the proper equipment to measure it. I know the active preamp may introduce its own distortion, but i wanted to know if the odd harmonic in the original signal is only there when DACs digital level is high.

It's never solved with lowering volume, but if you reduce volume to below 25 or so, 3rd harmonic will drop below -100 dB relative to fundamental. Transparent to most but it will never meet spec until actually fixed.

 

[the_brunx]

Still waiting for SMSL to reply…

 

[MusicNBeer]

@the_brunx, nice one, all you can do at this point is laugh. I've accepted my M500 V1 will never be fixed.

 

[juanjosaudio]

It's never solved with lowering volume, but if you reduce volume to below 25 or so, 3rd harmonic will drop below -100 dB relative to fundamental. Transparent to most but it will never meet spec until actually fixed.

Thanks so much for your answer!! "Relative to fundamental" part was so clarifying!! so if i understand well using a buffer clean (linear) active line preamp will reduce the the problem, at least what i can percieve after knowing, but not solve It in the sense of device still performing under specified THD. I Hope they do set Up that european repair shop eventually so i can send them my two M500 to get them fixed. Another before that solution would be i Guess to put some patch (with Jack or similar software) in the streamer (if It is a computer) so i can use one M500 for left Channel and the other for right Channel. I know , this is unacceptable , you are getting 1/2 of what you paid for! And that wont work with DSD or MQA streams i guess.

 

[juanjosaudio]

Way way back in this thread somewhere near the beginning of time I recall seeing that the issue is reduced at lower DAC output. 30 or 32 I think it was. A clean amp with enough grunt will cover that, both my Schiit Heresy and SMSL SH-9 will happily run my Hifiman Sundaras this way even with eq. But there is not much headroom, so if you have very hungry headphones you might want more.

Thanks for the info!!! Maybe a clean line level active preamp in between DAC and AMP does get rid of that headroom problem.

 

[MusicNBeer]

@juanjosaudio, brilliant idea! If you have two units, you can use one for each channel. You even have a balance conrol with volume adjustments.

 

[juanjosaudio]

@juanjosaudio, brilliant idea! If you have two units, you can use one for each channel. You even have a balance conrol with volume adjustments.

We have a made up sentence , may we laught so we dont cry. Here a Pic of my SMSL M500 Dual mono DAC setup.

 

[MusicNBeer]

Exactly, it was worth a laugh.

 

[SHENZHENAUDIO]

Still waiting for SMSL to reply…

View attachment 138652

Pls directly email Mandy, or anything we can do?

 

[the_brunx]

Pls directly email Mandy, or anything we can do?

I already did do that.
But let me PM you now and see where it goes.

 

[MusicNBeer]

Maybe there is hope afterall...

@SHENZHENAUDIO, I bought my M500 direct from you guys. Do you have a process in place to do fixes from USA? Thanks!

 

[Jeriko]

Is there any “empirical value” regarding the repair process? Has anyone go through it and is satisfied with the results?

 

[SHENZHENAUDIO]

Maybe there is hope afterall...

@SHENZHENAUDIO, I bought my M500 direct from you guys. Do you have a process in place to do fixes from USA? Thanks!

Yes, pls email [email protected], our colleague will project your issues.

 

[Paulo83]

Of those that have mentioned they have updated m500 devices, can anyone confirm if they have done this themselves and if so where you got the firmware from please?

 

[Laserjock]

Yes, pls email [email protected], our colleague will project your issues.

Does Cloris know of this issue?

 

[SHENZHENAUDIO]

Does Cloris know of this issue?

Yes, she knows well. Just email and share your order info and SN in picture.

 

[Laserjock]

Yes, she knows well. Just email and share your order info and SN in picture.

Then it’s odd she would respond with a question whether I “hear a difference?” when I posed the question to how to get mine updated.

Chris