Questions about an eBay SA9227 DAC from a newbie

VaKo

Member
2016-02-15 3:22 am
I'm new to this type of stuff, but you might be able to help me.

I purchased a very cheap SA9227+PCM5102 DAC from eBay sold as a DA3. Nothing special but it was cheap enough to buy on a whim. I had the same issues Takeshi had here, after a few hours of use it would just stop and needed to be removed and re-connected.

After some playing about, I have discovered that the issue appears to be heat. I have identified the chips with the issues here, the chips (mosfets?) circled in yellow get very warm, while the chip circled in white (the sa9227) gets blazing hot to the point that I can't touch it. I've a affected a repair by attaching some copper Raspberry Pi heatsinks to all 3 chips, and a 4th heatsink to the PCB under the SA9227, and this (combined with running it outside the case) seems to have fixed the heat issue and maybe improved the sound quality slightly.

So my question is, is this level of heat output normal with these electronics (and the unit not designed to cope with it) or have I just extended the life of something which is at best half way to dead?

Lastly, if I wanted to replace this with something which does kinda the same thing (USB in, RCA out, works with Windows 10) what would you recommend as a known good option? I don't mind Aliexpress and a bit of soldering.
 
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The datasheet I was able to find for the Savitech SA9227 USB interface made no mention of supply current or supply voltage so I've not been able to verify if the part is designed to run hot or not. My instinct says not so this makes me wonder if the wrong voltage regulator has been fitted to your board.

The parts you've circled in yellow are most probably the voltage regulators - if you have a voltmeter it would be a good idea to check the voltage on each of the three pins of each.

Measure the voltage relative to the screen terminals of the output RCA sockets btw.
 
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While I was searching for any other examples of overheating of this chip, I did find one Taobao DAC where the SA9227 has a heatsink on top. But also several without.

Suggest you look for a DAC with the Tenor USB interface - its not high speed but it certainly runs fairly cool. No idea if that's Win10 compatible but on Win7 I had no problems with a TE7022 based adaptor. Something like this - 24 BIT 96K USB DAC Headset Amp TE7022+CS4398+OPA2132 Headphone Amplifier Board-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
 

mroboto

Member
2018-01-12 8:29 pm
Hello everyone,

I bought this DAC recently and had the DAC frequently stop working symptom.

I removed the case and used it directly on the floor for a few days, and he didn't stop working, but touching the SA9227 chip, feels hot !

I found two possible fix.

1. Install an 10x10x10mm heat sink on the SA9227 chip

2. And thats where this is interesting, awaiting for heatsink to come, I had some parts in hands to start to modify it , so I started there.

I installed a 0.1uf 100V ceramic disc cap to the left pins 1&2 of the left AMS1117 regulator that seems to lead to the SA9227 chip. Now the SA9227

Also installed a 10uf 50V multilayer ceramic cap to the left pins 1&2 of the right AMS1117 regulator that seems to lead to the PCM5102A DAC chip.

The bypass cap added for the PCM5102A DAC chip supply may improve the quality of sound by providing a cleaner curent, but the one added for the SA9227 may also help reduce heat of the SA9227 chip.

Listened it for a few days without the case, sometimes I touched the chip and is moderately warm compared to before.

Now I put the case back on, pluged it and listened it all day long yesterday, leaved it plugged for the night, and listened today, no cut off at all.

To improve the sound quality even more, I replaced the electrolytic 10uf output caps by Wima MKS2 10uf 50V

I think that if he continues to work without cutting out, I will not have obligation to stick an heatsink on the SA9227 chip.

I take some pictures:

Clic on the link at the right of "Document Joint" to see full sized pictures

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This DAC sounds pretty good with the mods I done.

Hope this helps people who have problems with this DAC and/or want to improve it.
 

mroboto

Member
2018-01-12 8:29 pm
In one month and a half, he freezed once,

So I decided to replace the 0.1uf ceramic disc I added to the SA9227 regulator (the left one) , with a 4.7uf multilayer ceramic cap.

And I also replaced the 0.1uf ceramic disc I previously added to 5V input with a 2.2uf multilayer ceramic cap.

If the problem is not completely solved with that, I will install the heatsink on the SA9227 chip as I previously said, I hope I will not have to do that, because I want to see the chip, not hidden under a heatsink, for future reference.
 
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phase

Member
2004-10-04 11:59 pm
I have an sa9227 and it doesn’t run hot, but it’s in more of an open frame with a fan on the entire dac/headamp.
I can’t imagine how those kit DACs would work very well in a closed case, mine gets warm enough to overheat a bit just without the fan on.

Edit; mine is an sa9223, not sure if that was a monumental upgrade or not.
 
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phase

Member
2004-10-04 11:59 pm
Right, that’s the one, is the best thing I could find to work with my work computer, with no access to permissions to use anything with a dedicated driver.

Probably need an infrared thermometer to see how hot it really is, and if it’s anything to be concerned about. My experience with holding a finger on something hot has shown that I can hold on if it’s less than 138 degrees.
 

mroboto

Member
2018-01-12 8:29 pm
You can use the SA9227 without installing a driver in Windows 7 , but I think that it sound better with the driver installed, also, the frequency is limited to 96Khz without the driver, as the SA9023,

But can go up to 384Khz with the driver installed, foobar2000 plugins , ASIO proxy etc...
 

phase

Member
2004-10-04 11:59 pm
I just did something similar to a dac, usb board. It used some regulators, 17-33, the data sheet said to be sure and use output capacitors that were between .033 - 2.2ohms to settle the reg. It also mentioned to keep them close like you have.
I know it made a huge difference in the performance, I used some 47uf polymer(nichicon lf).