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strange SMSL M500 high 3rd harmonic
- Thread starter liu
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So you're thinking this is a firmware error in both SU9 and M500? And this error has been present since M500 was introduced?
Probably much less with speakers than with headphones, -75dB 3rd harmonic would be right at the threshold, so for you with your particular system it might not be.
Thats what I wanted to know. My System is not really bad. Raspi-Digi2pro -> SU9 -> HifiAkademie DSP -> XTZ EDGE A2-300 -> https://www.lautsprechershop.de/hifi/accutop.htm
Maybe you are right and it might still be only audible with very good headphones. I am happy that I dont hear "it" as the SU9 is the perfect DAC for my needs. So .. then lets look forward that SMSL provides soon a FW upgrade.
Maybe you are right and it might still be only audible with very good headphones. I am happy that I dont hear "it" as the SU9 is the perfect DAC for my needs. So .. then lets look forward that SMSL provides soon a FW upgrade.
Amir shows the SU-9 as measuring close to perfection, referring to it as "instrument grade" DAC. How is this possible?
There can be holes in measurements. It's difficult to keep a review comprehensive while extremely in depth. There's a formula that every dac runs. Over time, it can be improved or updated. It's a very bizarre issue that no one foresees it.
If I were you I just remove the Digi2pro and use the USB input of the su-9 unless you utilize a rpi < 4.
I had it running like this before, but the USB detects always if the SU9 is on and switched to USB which in certain situations was pain in the a***
. With the Digi its exactly how I want to use it. Then it doesnt care whats going on with the SU9. From the Sound point of view I dont see any difference even I use a RPI4 (at least I dont remember any).Perhaps Amir's reviews need to be updated over time to incorporate these additional tests. As it stands, these potential gaps in his testing means he is recommending flawed/broken products.
It's also been suggested that @amirm test for mode and sample rate switching noise. I'd also like to see tests for power on/off noise.
while i think it would be nice, one factor to consider is the time involved in performing the current test suite. if he recommends a few products with flaws, well, he'll still be doing leagues better than the median reviewer.
JSmith
Master Contributor
Yeah I don't think it's fair at all to try and pin this on Amir... people and manufacturers send him stuff, he tests it, simple as that. There are no guarantees made about the performance of any other units or possible "golden samples"... this is out of his hands. Recommendations are based on the unit tested, nothing more.
The problem being discussed here is solely SMSL's responsibility. So hoping to see a firmware update and instructions on how to flash soon.
JSmith
August
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Maybe stm32 burner? Just like the way D5 does.
- Thread Starter
- #358
I think that is the case. for m500 you have to open the case. for SU-9 has the connector in the bottom.
I think so.
hmm so to update the firmware you need a special hardware tool? sorry is not clear for me what smsl is sending you.
is not possible to do a firmware update by software?
the usb interface is on the XMOS micro. this micro does not control the dac chip. a different micro controls the dac chip. in order for the xmos micro to write to the nvram on the micro that controls the dac chip, appropriate wiring needs to exist. if this wiring does not exist, the the xmos and hence the usb interface will not be able to write to the nvram of the micro that controls the dac chip. we don't know if this wiring exists. they may not even be sure at this point if the wiring exists.
su-9 has an exposed header that directly connects to the dac micro. so does the sabaj d5. m500 does not. i am relatively sure that there is a jtag ribbon header internal to the m500 that allows debug access to the dac micro. this means that, yes, the nvram on the dac micro is upgradable. however, only if you open the m500 and use a device that directly connects to that internal header.
a couple of things are possible. one is that smsl is only sending the device for the su-9 that connects to the external header. it's a newer dac and they may have figured out how to fix this bug earlier on the su-9 than the m500. the other possibility, the one we're afraid of, is that they are sending both a tool for the su-9 and a tool for the m500. this would mean that they have no way to access the dac micro from usb on the m500 so they're sending him a ribbon and burner for the m500 that requires opening the m500 to use.
regardless, we have no idea until Prof Wolf gets his package. hold onto your horses until then
su-9 has an exposed header that directly connects to the dac micro. so does the sabaj d5. m500 does not. i am relatively sure that there is a jtag ribbon header internal to the m500 that allows debug access to the dac micro. this means that, yes, the nvram on the dac micro is upgradable. however, only if you open the m500 and use a device that directly connects to that internal header.
a couple of things are possible. one is that smsl is only sending the device for the su-9 that connects to the external header. it's a newer dac and they may have figured out how to fix this bug earlier on the su-9 than the m500. the other possibility, the one we're afraid of, is that they are sending both a tool for the su-9 and a tool for the m500. this would mean that they have no way to access the dac micro from usb on the m500 so they're sending him a ribbon and burner for the m500 that requires opening the m500 to use.
regardless, we have no idea until Prof Wolf gets his package. hold onto your horses until then
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