M500 problems I have confirmed so far
1. When playing DSD2.8MHz, suddenly it becomes big continuous intense noise.
2. When playing a PCM768kHz file, the sound is severely distorted.
3. Even when PCM768kHz seems to be operating normally, puti puti bubble noise such as scratch sound of the record board that does not exist in the original music file occurs.
4). In addition, even with DSD 11.2MHz playback, a little noise came out.
5. A factory reset has no effect on these symptoms.
If you switch the USB cable to Topping D50s DX3 Pro, it will play normally.
Does your M500 have these symptoms?
I then returned the product to the dealer.
I also experience some of these symptoms, but I figured out some setting which maybe related to them. I use Foobar2000 v1.4.4, with the newest version of foo_input_sacd component.
Problem 1 3 4 all have some relation with the 'DSD native' setting and some implementaion issue of the M500's usb interface. When I first got the M500 I used some DSD64 128 256 and 512 files to test. When using the newist version of foo_input_sacd, and setting the output device to 'DSD:ASIO:USB DAC ASIO' I notice those bubble noise when playing DSD256 files, while unable to play DSD512 files showing 'sample rate of 14112000Hz not support by device'. No problem playing DSD64 and 128 files. I then tried a older vision of foo_input_sacd v0.9.6, this time I have no issue playing DSD128 and 256 files, DSD512 files will play but again has the bubble noise. And when changing from other format to DSD64 (I didn't try all situation but all of the issues come after I change from another format to DSD64, no problem when changing between DSD64 tracks) and after about 30 seconds white noise will suddenly cut in and last for about 10 seconds, after this the music will continue to play normally and no problem until changing to other format then change back.
I searched on the internet and found that foo_input_sacd v0.9.6 is the final version which still support DSD native output, anything newer will only output using DoP(DSD over PCM) which lead to the '14112000Hz not support' problem, as DSD512 DoP is based on 1411.2KHz PCM stream which M500 dosen't support. DSD256 DoP is based on 705.6K PCM, which is supported but there could be some issue causing the signal to pop, 768KHz and DSD512 native(22579.2KHz 1bit) may has the same problem which explained problem 3. Also there is another problem which cause the DSD64 native signal to suddenly jump to noise after changing format and playing for 30s which I think maybe is due to some buffer error.
So I now use the DSDTranscoder plug-in which can set different output method for different DSD format. I set every DSD64 to using DoP output, while other format output DSD native, which solves problem 1 and 4. But DSD512 together with 705.6 and 768KHz will still be a problem, not the end of the world since these resources are pretty rare in my opinion...
I think all these issues come from the usb interface chip - the XMOS XU-216 which appears on a SMSL product the first time. I also report these problems to the manufacture so maybe there will be a new firmware to solve them.
I already had the M500 for more than one month so not able for me to return it (also because I'm loving its sound and appearence). It's your decision whether to return it or not.
