SMSL SU9-n issue

[Gradius]

Please, keep us informed.

 

[Nick_L]

Hello Horias,

I think I have the same issue but with another model. Please find my findings regarding an SMSL SU-6 below:

SMSL SU-6 crackling sound issue

Dear all, sorry I am not sure if this is the right forum. So please apologize if I should find another forum/section. A couple of days ago I identified a crackling sound issue with my SMSL SU-6 DAC which is a couple of months old only. The issue comes and goes and it is very difficult to...

www.audiosciencereview.com

I am waiting now for a repair but I will track your updates closely.

All the best
Nick

 

[horias2000]

Hello Horias,

I think I have the same issue but with another model. Please find my findings regarding an SMSL SU-6 below:

SMSL SU-6 crackling sound issue

Dear all, sorry I am not sure if this is the right forum. So please apologize if I should find another forum/section. A couple of days ago I identified a crackling sound issue with my SMSL SU-6 DAC which is a couple of months old only. The issue comes and goes and it is very difficult to...

www.audiosciencereview.com

I am waiting now for a repair but I will track your updates closely.

All the best
Nick

I just had a quick look online and it seems like the SU-6 has a similar (if not identic) clock generation circuit. So yes, it might be the same thing.
This is from the SU-6. It is very similar to what I have on the SU-9n

 

[horias2000]

OK, today I received the part and I replaced it. BINGO!!! Everything sounds just fine and I get no more interruptions. I had a quick look with the scope and the generated clock looks good (a bit better than the original). I also used the hot air de-soldering station on 70C to heat up the IC and I did not get any interruptions anymore. Doing this test with the hot air at 70C would interrupt the audio almost instantly.

So I think it is safe to say that that was the defective part. I will listen to the DAC for the entire weekend and I'll report back if I get any issues.

To sum everything up, the problem came from a clock generator IC that I think was either damaged during production when its part number was removed (probably by laser) or it was not genuine. I replaced the IC with SI5351A-B-GT. I got it from DigiKey (https://www.digikey.ro/ro/products/detail/skyworks-solutions-inc/SI5351A-B-GT/3679847) but it can be found at Mouser as well (https://eu.mouser.com/ProductDetail...nc/SI5351A-B-GT?qs=p9T7GgSe1IEO%2BMfC/KPFfA==).

The 49MHz (for 192kHz sampling rate audio output) that is used by the ES9038PRO chip

 

[Nick_L]

Hello horias2000,

congratulations to your success! Great work! I have sent my DAC to shenzhenaudio.com for repair/warranty and will contact you again in case my DAC is broken again

Cheers
Nick

 

[horias2000]

I'm happy to report that after almost two weeks the DAC works just fine. No more interruptions. All is fine.
I also want to say that SMSL replied to my email after two weeks and they advised me to contact the seller and not them. Needless to say I won't be bothering with this

 

[Snoopy]

I doubt I would have had that patients.
I would have just ordered a new unit from the same retailer and returned the old unit as DOA in the box of the new one.

 

[will_hl]

@horias2000, thank you so much for sharing this!

My SU-6 started to generate this crackling noise after being turned on for a while. I was about to throw it alway, then i saw this thread.

First i checked to see if the IC was indeed the problem, and after applying some heat the SU-6 immediately started to crackling.

As i live in Brazil, importing the SI5351A from US was out of the question (too expensive), my options were getting from Aliexpress from a sketchy manufacturer or trying to fix the heat issue (or maybe both?).

I jumped to the faster and cheap solution that is trying to fix the heat issue. And its working again!

I added a little heat sink from a step motor controller on the IC:

The problem did not appear anymore, after adding the heatsink .
But just to make sure i added a 3,5mm thermalpad equivalent (seems gross but does the job) in the back side of the PCB to make contact with the aluminium case:

I was going to use this aluminum heatsink, but I would need to reduce its height to fit between the PCB and the case. The thermalpads were a faster solution*

Notes:

The SU-6 is working after that quick-fix.

The problem returned only after i applied heat directly to the SU-6 case using a hair dryer. At about 60°C (140°F), measured from the case.
Wich is way above the temp that is usually working ~35°C (95°F).

To be honest, with that info, I don't know if the problem is the crap/damaged IC or the specifications from the chip were not taken into account in the design (thermal conditions). (maybe both?)

Again,
Thanks for sharing this info about SMSL SU-9. This saved my SU-6.

 

[Snoopy]

@horias2000, thank you so much for sharing this!

My SU-6 started to generate this crackling noise after being turned on for a while. I was about to throw it alway, then i saw this thread.

First i checked to see if the IC was indeed the problem, and after applying some heat the SU-6 immediately started to crackling.

As i live in Brazil, importing the SI5351A from US was out of the question (too expensive), my options were getting from Aliexpress from a sketchy manufacturer or trying to fix the heat issue (or maybe both?).

I jumped to the faster and cheap solution that is trying to fix the heat issue. And its working again!

I added a little heat sink from a step motor controller on the IC:
View attachment 294650


The problem did not appear anymore, after adding the heatsink .
But just to make sure i added a 3,5mm thermalpad equivalent (seems gross but does the job) in the back side of the PCB to make contact with the aluminium case:

View attachment 294658

I was going to use this aluminum heatsink, but I would need to reduce its height to fit between the PCB and the case. The thermalpads were a faster solution*
View attachment 294664

Notes:

The SU-6 is working after that quick-fix.

The problem returned only after i applied heat directly to the SU-6 case using a hair dryer. At about 60°C (140°F), measured from the case.
Wich is way above the temp that is usually working ~35°C (95°F).

To be honest, with that info, I don't know if the problem is the crap/damaged IC or the specifications from the chip were not taken into account in the design (thermal conditions). (maybe both?)

Again,
Thanks for sharing this info about SMSL SU-9. This saved my SU-6.

the heatsink and the Thermalpad is a nice "fix". a prober designed and tested device would probably not need this or already come equipped with that stuff. I guess that's the price for "small" + "cheap".
you might as well drill a few holes in the side of the case, for better air circulation.

I added "proper" hifi feet to my SMSL D300 DAC and SP400 headphone amp. because stacked on top of each other they would get pretty warm.. no issues yet but now its a night and day difference compared to these cheap rubber feet they came with.

 

[horias2000]

@horias2000, thank you so much for sharing this!

My SU-6 started to generate this crackling noise after being turned on for a while. I was about to throw it alway, then i saw this thread.

First i checked to see if the IC was indeed the problem, and after applying some heat the SU-6 immediately started to crackling.

As i live in Brazil, importing the SI5351A from US was out of the question (too expensive), my options were getting from Aliexpress from a sketchy manufacturer or trying to fix the heat issue (or maybe both?).

I jumped to the faster and cheap solution that is trying to fix the heat issue. And its working again!

I added a little heat sink from a step motor controller on the IC:
View attachment 294650


The problem did not appear anymore, after adding the heatsink .
But just to make sure i added a 3,5mm thermalpad equivalent (seems gross but does the job) in the back side of the PCB to make contact with the aluminium case:

View attachment 294658

I was going to use this aluminum heatsink, but I would need to reduce its height to fit between the PCB and the case. The thermalpads were a faster solution*
View attachment 294664

Notes:

The SU-6 is working after that quick-fix.

The problem returned only after i applied heat directly to the SU-6 case using a hair dryer. At about 60°C (140°F), measured from the case.
Wich is way above the temp that is usually working ~35°C (95°F).

To be honest, with that info, I don't know if the problem is the crap/damaged IC or the specifications from the chip were not taken into account in the design (thermal conditions). (maybe both?)

Again,
Thanks for sharing this info about SMSL SU-9. This saved my SU-6.

Glad to hear my findings helped. In my experience the fix you implemented (extra cooling) will work but only temporary. It will most probably start doing the same at a lower temperature. Another fix that might work if you really can't get the IC, is to try an lower the Vcc to the minimum specified in the datasheet. This should lower the overall power dissipated by the IC. You can try and lower the voltage by adding a voltage divider on the Vcc pin or by adding a small voltage regulator. You can also try and order the IC from aliexpress. Even if it's fake, it might just work. It can be that the IC was damaged during assembly.

 

[will_hl]

the heatsink and the Thermalpad is a nice "fix". a prober designed and tested device would probably not need this or already come equipped with that stuff. I guess that's the price for "small" + "cheap".
you might as well drill a few holes in the side of the case, for better air circulation.

I added "proper" hifi feet to my SMSL D300 DAC and SP400 headphone amp. because stacked on top of each other they would get pretty warm.. no issues yet but now its a night and day difference compared to these cheap rubber feet they came with.

Thats nice, i use the SU-6 and SH-6 stacked and they get pretty warm...

Glad to hear my findings helped. In my experience the fix you implemented (extra cooling) will work but only temporary. It will most probably start doing the same at a lower temperature. Another fix that might work if you really can't get the IC, is to try an lower the Vcc to the minimum specified in the datasheet. This should lower the overall power dissipated by the IC. You can try and lower the voltage by adding a voltage divider on the Vcc pin or by adding a small voltage regulator. You can also try and order the IC from aliexpress. Even if it's fake, it might just work. It can be that the IC was damaged during assembly.

Yes i totally agree.
Yesterday I ordered a new IC. I don't think this "fix" will last long...
Once the eletronics starts to show problems, the best solution is to replace them.

I will update the results when it arrives...
Thanks for the suggestions!

 

[Lexxz]

I bought from HIFIGO SMSL SU-9n on September 20, 2022. By the way, I live in Hungary. My headphone system consists of: SMSL SU9 DAC+ SH9 Amp+ XLR Cable + Player Moode RPi4+ HIFIMAN Arya-Stealth Magnet Version+XLR Cable+Synology MusicServer.
The whole system functioned perfectly. I use mostly DSD files for listening. However, about a month ago, while listening to music, crackling and loss of sound began to be heard.
At first I did not pay attention, but every day this phenomenon intensifies. Today it looks like this: I turn on the system, listen to music, everything is fine. But after about 40 minutes, a very strong crack appears, it is not possible to listen to music. I turn on the pause, the crackle continues and disappears only after turning off the power to the DAC. I tested the SMSL SU-9n on my main system, with a different player and amplifier.
The result is unchanged, after 40 minutes there was a crack and interruption of the sound. I have not yet contacted the seller for help, I don’t know how much it can really be repaired without shipment to China.

 

[microcontrollerpro]

I bought from HIFIGO SMSL SU-9n on September 20, 2022. By the way, I live in Hungary. My headphone system consists of: SMSL SU9 DAC+ SH9 Amp+ XLR Cable + Player Moode RPi4+ HIFIMAN Arya-Stealth Magnet Version+XLR Cable+Synology MusicServer.
The whole system functioned perfectly. I use mostly DSD files for listening. However, about a month ago, while listening to music, crackling and loss of sound began to be heard.
At first I did not pay attention, but every day this phenomenon intensifies. Today it looks like this: I turn on the system, listen to music, everything is fine. But after about 40 minutes, a very strong crack appears, it is not possible to listen to music. I turn on the pause, the crackle continues and disappears only after turning off the power to the DAC. I tested the SMSL SU-9n on my main system, with a different player and amplifier.
The result is unchanged, after 40 minutes there was a crack and interruption of the sound. I have not yet contacted the seller for help, I don’t know how much it can really be repaired without shipment to China.

I am also having the same issue on my SU-9N. The noise got so bad that it triggered overcurrent protection on my Topping A30 Pro.
I have attached a recording of the noise:

 

[Lexxz]

The problem remained with the open case. Nothing changed.

 

[Essar]

I purchased in June and noticed the horrendous crackling but it seemed to go away. This is because I don't have enough time to listen long enough for the heat threshold. I reset the SU-9 Pro, and the problem seemed to go away, so I thought it was some fluke in my particular settings configuration. Today it returned in spades and it's obvious this is the exact heat buildup described by @horias2000. I'm wondering if they're "recycling" bad DACs. By that I mean simply reselling in the hopes that the bad ones shuffle out to people who either don't listen long enough or at a volume level for it to become a problem. And what's wrong with ventilation holes as a solution?

I also have an SH9 power amp and I'm a bit jaded. I really don't want to send both of these devices back to Apos. May I ask for recommendations?

 

[horias2000]

I purchased in June and noticed the horrendous crackling but it seemed to go away. This is because I don't have enough time to listen long enough for the heat threshold. I reset the SU-9 Pro, and the problem seemed to go away, so I thought it was some fluke in my particular settings configuration. Today it returned in spades and it's obvious this is the exact heat buildup described by @horias2000. I'm wondering if they're "recycling" bad DACs. By that I mean simply reselling in the hopes that the bad ones shuffle out to people who either don't listen long enough or at a volume level for it to become a problem. And what's wrong with ventilation holes as a solution?

I also have an SH9 power amp and I'm a bit jaded. I really don't want to send both of these devices back to Apos. May I ask for recommendations?

I'm not sure if they recycle them or if it's bad(fake) chips or if they damage the chips during production when they erase the marking from the chip. Adding vent holes will not solve the issue as the chip will start developing the issues at lower temperature as time goes by. I also tried adding a heatsink and it was OK for a while but it started doing the noises again after a while. Try cooling the IC in some way. You can also try touching it with your finger but be careful with ESD. Make sure you discharge by touching a metal part of some sort (ideally connected to earth). The only way to completely cure this issue is to replace the IC with one from a trusty vendor. The listening level doesn't have anything to do with this issue. This IC is not affected by the level of the output signal.
As for the power amp, there should be no issue with it. I do not think the amplifier uses this IC for clock generation.

 

[horias2000]

The problem remained with the open case. Nothing changed.

Did you try to cool the IC in some way? You can try touching it with your finger but please do make sure to discharge before as this is a very ESD sensitive area. Just touch a metal part that is ideally connected to earth. If you keep your finger over the IC a few seconds, it should star working or you should be able to hear an improvement.

 

[Lexxz]

Yes, I touched it with my finger, but nothing changed. And crackle starts 10 minutes after switching on.

 

[Lexxz]

I wrote to the dealer. And they asked me the following question: "The brand side means to let you keep a file suffix, do not switch between DSD and FLAC, try to see the result. They want to confirm whether there is a problem with the internal components." I just don't understand what they want. Maybe you can explain this question to me.

 

[horias2000]

Yes, I touched it with my finger, but nothing changed. And seisas crackle starts 10 minutes after switching on.

Sounds like the same issue I had but probably the IC has more damage than mine had. The only way to make sure is to replace the IC and see if the problem goes away. If it's still there after the IC is replaced, then it is something else. Somebody with a decent soldering station a some experience should be able to replace the IC without any issues.