SMSL DA9 - Wait and see, or solid buy?

[matchi]

The measurement result is the same as in my case.

At 120 mV, there will be a noticeable level of pop noise.
According to the MA12070 standard for amplifier chips, the maximum offset voltage is 60 mV. That's twice as much. The problem is that this offset voltage is constantly fluctuating. Sometimes it will be a higher voltage. And it's a little scary to imagine if the amp chip breaks in the future.
I have tested many class D amplifiers so far, but the DC offset voltage of the output was less than 15mV.
If you bought the DA-9 and don't feel any pop noise, the output DC offset voltage is probably less than 15mV. That is the original normal value.

The DA-9 momentarily mutes the MA12070 chip when the power is turned on / off and when the input is switched. This behavior is to prevent pop noise.
When mute is turned on, the offset voltage of the SP output becomes 0 mV, and when mute is turned off, the offset voltage is generated again. A voltage fluctuation of 0 mV >> 120 mV drives the speaker and is output as pop noise.

Thanks for the infos

I just tested my original DA-9 which had a slight pop on the right channel and it measured 19 mV on both channels, pop is almost inaudible now. Wish I measured it when I first got it, will be keeping an eye on both now though.

 

[Toku]

Thanks for the infos

I just tested my original DA-9 which had a slight pop on the right channel and it measured 19 mV on both channels, pop is almost inaudible now. Wish I measured it when I first got it, will be keeping an eye on both now though.

My concern is that pop noise goes on and off over time every day. That means that the DC offset voltage is fluctuating.
The DA-9 that arrived at me had pop noise only from the right channel. It's a level of pop noise that I care about. However, it did not appear at all over time.
I measured the offset voltage with the DA-9 turned on for a week.
As a result, the maximum value was 126 mV and the minimum value was 0 mV. It fluctuated constantly between 126 mV and 0 mV during the week. At 15 mV or less, you will not feel any pop noise.
The offset voltage of the left CH at that time was about 8 mV and hardly fluctuated. Of course, there is no pop noise from the left channel.

From the information obtained so far, the symptoms of DA-9 are
Products that do not produce pop noise at all
Products that generate pop noise only from the left CH
Products that generate pop noise from both the left and right channels
It can be classified into three categories.

No such symptoms have been reported for the AO200 and Sabaj A20a, which have the same amplifier circuit as the DA-9. I bought the Sabaj A20a and the DC offset voltage was stable in the single digits.
I also ordered the AO200 today, so I will test it in the same way when it arrives.

 

[escape2]

Regarding the S.M.S.L AO200, has anybody other than myself noticed the USB input?

Yes, we've noticed - it was mentioned earlier in this thread.

And if it truly is a USB input, what DAC is being used?

 

[Toku]

Yes, we've noticed - it was mentioned earlier in this thread.

And if it truly is a USB input, what DAC is being used?

According to reports, when connected to a Windows PC, USB is recognized only at 48kHz/16bit, and others are not displayed and cannot be selected.

 

[SOUNDSONIC]

My concern is that pop noise goes on and off over time every day. That means that the DC offset voltage is fluctuating.
The DA-9 that arrived at me had pop noise only from the right channel. It's a level of pop noise that I care about. However, it did not appear at all over time.
I measured the offset voltage with the DA-9 turned on for a week.
As a result, the maximum value was 126 mV and the minimum value was 0 mV. It fluctuated constantly between 126 mV and 0 mV during the week. At 15 mV or less, you will not feel any pop noise.
The offset voltage of the left CH at that time was about 8 mV and hardly fluctuated. Of course, there is no pop noise from the left channel.

From the information obtained so far, the symptoms of DA-9 are
Products that do not produce pop noise at all
Products that generate pop noise only from the left CH
Products that generate pop noise from both the left and right channels
It can be classified into three categories.

No such symptoms have been reported for the AO200 and Sabaj A20a, which have the same amplifier circuit as the DA-9. I bought the Sabaj A20a and the DC offset voltage was stable in the single digits.
I also ordered the AO200 today, so I will test it in the same way when it arrives.

Looking forward for your test results of the AO200. And thank you for the informations you are sharing re DA9.

 

[Poultrygeist]

I lack interest with things in audio that I can not hear.

 

[fluxcapacitor]

i've received my 2nd DA9, 1st one returned due to freezing at smsl logo at booting,,,,2nd one has Left channel pop, measured DC offset, L channel 150mv, Right channel 0.004mV...SMSL seems never considered this criteria during desing & development phase....

 

[matchi]

i've received my 2nd DA9, 1st one returned due to freezing at smsl logo at booting,,,,2nd one has Left channel pop, measured DC offset, L channel 150mv, Right channel 0.004mV...SMSL seems never considered this criteria during desing & development phase....

Get it refunded and go for the AO200. I'd be doing that if I didn't have two DA-9s now but will live with the pop and see what happens.

 

[fluxcapacitor]

Get it refunded and go for the AO200. I'd be doing that if I didn't have two DA-9s now but will live with the pop and see what happens.

actually i'm unfortunately ok with pop noise but worried about dc on L channel, it's 150mv and quite high i think. I will probably go for Sabaj A20, no pop, no dc, no freezing etc. ...it looks quite robust.

 

[Poultrygeist]

I would not keep a defective piece of gear.

FWIW I ordered my DA-9 from Amazon weeks before the Prime Day sale and shipping took longer as it came from China. The units included in the Prime Day sale were stored in a US warehouse as they arrived within a few days of purchase.

 

[Toku]

This is a preliminary report testing the AO200.

Today the AO200 was delivered from Amazon.jp and I immediately tested it.
I have already been conducting energization tests for several hours in a row, but no problems have been seen so far.

There is no pop noise when turning the power on / off and switching the input, which was a problem with the DA-9.

The white noise emitted from the speaker when there is no sound can be heard slightly when you attach your ear to the SP unit. There are really few.

The DC offset voltage of the speaker output was 6.0mV for R-ch and 17.1mV for L-ch.
The value of L-ch is a little large, but there is no problem because the measured values are stable for both channels. There is no offset voltage fluctuation that was a problem with the DA-9.

I tried the relay operation sound of the power supply unit, which was a problem with the Sabaj A20a, with the same music source, but there is no problem at all. This issue doesn't seem to be relevant to the AO200.

The USB connection is recognized as the default "USB AUDIO" in Windows10. The sun plate and bit are fixed at 16bit 4800Hz, and others cannot be selected. It's a lonely specification compared to the SA300's USB, but the sound is better than the SA300.
In actual playback, all files are resampled to 16bit 4800Hz, so there is no problem.
I tested using 16 / 24bit files from 44.1kHz to 768kHz and had no problems playing.
This USB connection is by no means a bonus function, and is at a level that is as practical as RCA.

BT is displayed as SMSL BT5.0C and you can connect smoothly. I rarely use BT, but it sounds much better than the previous BT.

The AO200 has an automatic display off function, which works very conveniently.
I am happy that the functions I requested from each company have finally been realized.

Overall, the AO200 (Aoshida HiFi version) is a complete model based on the DA-9 and A20a, with each feature working perfectly.

I will continue the energization test for one week in a row.
I pray that it will work stably. If you find any problems, I will report them.
(I'm sorry in English full of mistakes)

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[Additional report]

Troublesome specifications of USB connection.
The USB input of the AO200 is not recognized just by connecting it to a PC with a cable. The PC cannot recognize it unless the input mode is switched to USB on the AO200 side.
If the AO200 is connected to a PC via USB input, the PC cannot be shut down normally. Be sure to switch the input of the AO200 to something other than USB or disconnect the USB cable.
This kind of operation was my first experience and at first I was very confused about how to handle it. The SA300, which has the same USB input, does not behave like this. It's a very annoying specification.

 

[matchi]

The units included in the Prime Day sale were stored in a US warehouse as they arrived within a few days of purchase.

Although mine was bought during Prime Day it wasn't in stock via Amazon and came direct from Shenzhen Audio which took just under two weeks. If I request a refund now I'd have to send both back to China, which would cost more than I'm willing to spend.

That said, I've messaged them again to see what they suggest as a way forward.

This is a preliminary report testing the AO200.

Today the AO200 was delivered from Amazon.jp and I immediately tested it.
I have already been conducting energization tests for several hours in a row, but no problems have been seen so far.

There is no pop noise when turning the power on / off and switching the input, which was a problem with the DA-9.

The DC offset voltage of the speaker output was 6.0mV for R-ch and 17.1mV for L-ch.
The value of L-ch is a little large, but there is no problem because the measured values are stable for both channels. There is no offset voltage fluctuation that was a problem with the DA-9.

I tried the relay operation sound of the power supply unit, which was a problem with the Sabaj A20a, with the same music source, but there is no problem at all. This issue doesn't seem to be relevant to the AO200.

The USB connection is recognized as the default "USB AUDIO" in Windows10. The sun plate and bit are fixed at 16bit 4800Hz, and others cannot be selected. It's a lonely specification compared to the SA300's USB, but the sound is better than the SA300.
In actual playback, all files are resampled to 16bit 4800Hz, so there is no problem.
I tested using 16 / 24bit files from 44.1kHz to 768kHz and had no problems playing.
This USB connection is by no means a bonus function, and is at a level that is as practical as RCA.

BT is displayed as SMSL BT5.0C and you can connect smoothly. I rarely use BT, but it sounds much better than the previous BT.

The AO200 has an automatic display off function, which works very conveniently.
I am happy that the functions I requested from each company have finally been realized.

Overall, the AO200 (Aoshida version) is a complete model based on the DA-9 and A20a, with each feature working perfectly.

I will continue the energization test for one week in a row. If you find any problems, I will report them.

Nice preliminary review, thanks for that.

I've continued to test the original DA-9 since yesterday and it's been very stable at 19mV per channel, the replacement device however, was up as high as 140mV L-Ch and 60mV R-Ch but continued to fluctuate +/- 25mV on the L-Ch.

This morning after an hour of being powered ON;
Original is measuring 15mV for L-Ch and 18mV for R-Ch.
Replacement is measuring 69mV L-Ch and 16mV R-Ch.

I'll continue to test throughout today and I'm hoping at least, that the original will continue to stay below 20mV.

 

[fluxcapacitor]

Although mine was bought during Prime Day it wasn't in stock via Amazon and came direct from Shenzhen Audio which took just under two weeks. If I request a refund now I'd have to send both back to China, which would cost more than I'm willing to spend.

That said, I've messaged them again to see what they suggest as a way forward.



Nice preliminary review, thanks for that.

I've continued to test the original DA-9 since yesterday and it's been very stable at 19mV per channel, the replacement device however, was up as high as 140mV L-Ch and 60mV R-Ch but continued to fluctuate +/- 25mV on the L-Ch.

This morning after an hour of being powered ON;
Original is measuring 15mV for L-Ch and 18mV for R-Ch.
Replacement is measuring 69mV L-Ch and 16mV R-Ch.

I'll continue to test throughout today and I'm hoping at least, that the original will continue to stay below 20mV.

That variability unity by unit is really worrisome.

 

[Poultrygeist]

Absolutely no issues from the many verified purchasers/owners of the DA-9 on Amazon. 13 five stars ratings and one four star ( missing antenna ).

Don't believe I've ever seen an amp rated this high before. If you buy it you can thank me later.

 

[fluxcapacitor]

Absolutely no issues from the many verified purchasers/owners of the DA-9 on Amazon. 13 five stars ratings and one four star ( missing antenna ).

Don't believe I've ever seen an amp rated this high before. If you buy it you can thank me later.

Probably most of them never bothered with pop noise, dc etc....if it works, its awesome for many

 

[Poultrygeist]

That variability unity by unit is really worrisome.

With thousands sold what would be the variability unit by unit that you speak of?

 

[Poultrygeist]

Probably most of them never bothered with pop noise, dc etc....if it works, its awesome for many

Pure conjecture on your part.

 

[fluxcapacitor]

With thousands sold what would be the variability unit by unit that you speak of?

many of these units have pop noise issue, dc values on either channel as high as 150mv but some of them has just close to zero. It seems smsl never bothered to prevent it during design development, you're alone with your luck. Also many units have smsl logo freeze sh.t which i had also.
for my case, i bought two of DA9, 1st one had smsl logo freeze issue, very tiny pop , L channel 0.000mv dc, R channel has 45-50mv...returned,,,2nd one has big pop noise issue, 150mv on L channel, 0mv on R...Don't tell me this is luck, this is lack of quality - lack of preventive design.

 

[Poultrygeist]

many of these units have pop noise issue, dc values on either channel as high as 150mv but some of them has just close to zero. It seems smsl never bothered to prevent it during design development, you're alone with your luck. Also many units have smsl logo freeze sh.t which i had also.

I'm only reading about the issues on this forum and I participate in several. It's also not mentioned in the reviews I've read. I'm hoping these comments don't turn out to be an exercise in splitting hairs.

 

[ShinMolina]

The latest post are getting me on my nerves. I've got my DA-9 at customs, maybe I shouldn't pay the import fees and just let the amplifier return to its homeland.

I hope not to find any issues. I will report anything I find, either good or bad. Fingers crossed!