"I tested OPT/COAX using a D10s and a Sony DVD player and it works perfectly fine."
Yes, but what about player connected directly to coaxial input of dx3+? I would like any feedback from people who have an old CD/Transport player hooked up via spdif to this unit. I had an e30 which didn't work well over spdif with the newer CS8416 spdif receiver, skipping/stuttering CD playback.
There aren't many S/PDIF signal sources I can use. Around me are Sony DVD players(COAX), Pioneer DVD players(OPT), and Sharp TVs(OPT).
So far, only Sony DVD players have had problems with S/PDIF. Topping's D50 and D50s COAX inputs couldn't connect to Sony at all. But it can be connected to many other DACs without any problems.
The D50/D50s issue was discussed several times with Topping technicians, but there was no clear answer.
From this experience, I purchased D10s and D10 Balanced as test equipment. When I buy a DAC, I first check it with D10s/D10b in an S/PDIF test. After that, we connect home appliances such as DVD players and check the operation.
Recently, the S/PDIF chip has been changed to CS8416 and some connectivity issues have been reported. I have purchased 3 E30s with different manufacturing years. CS8416 is used for the latest one. The CS8416 is also used in the E50 and DX3Pro+ that I just purchased. However, the problems reported so far have not occurred. I think this problem is very different depending on the appliances you connect to.