Like I said, I don't have a DVD player or DVDs lying around. And none of my Macs have SPDIF out. I'll try a few other options though to see if I can simulate it. Seems like maybe Firestick 4k (what I have) doesn't support DTS passthru, but the new 4K max one does.. So maybe I'll upgrade and try it out (it's time for a new one anyways 🙂 )
I tried my unit with video (again) after reading your note on latency. Like you said, it's indeed very difficult to find faults with this chip in that respect.
I hooked up the STA310 + my DAC to my LM3886 power modules via the RCA cables, just to test it out. It sounds really good. Like I'm surprised it even needs to be filtered, as I haven't done it yet. I don't hear any noise, even at high volumes and no audio playing. I'll still filter it, but that oversampling does a good job I think, and I have a a simple RC low pass filter on the front of the LM3886 as well. But I'm impressed with how it sounds so far. It crashed on me once half way through a movie, so I may have to add some logging to a SD card or something and see what happened. It could be the power supply crapping out like you said, but I'm sure I'll track it down. I have a laser temperature probe though, and the 3.3V regulator on the PSU hasn't even hit 30C yet, so I don't feel like it's struggling.
Here is a video of one of the first tests I did after the STA310 started working with my DAC. You can see the actual AMP over by the TV with the newly installed CNC machined front plate, and my test rig on the table with the STA310, power supply, microprocessor, and DAC board. I was must using my mini Bose computer speakers to test it in the video.
https://www.dropbox.com/s/zufzkhy3q0kq8r8/IMG_3220.mp4?dl=0
https://www.dropbox.com/s/zufzkhy3q0kq8r8/IMG_3220.mp4?dl=0
It maybe noise on the 2.5V line. BTW, did you skip the ferrite between the AGND & DGND of the PLL ? And is your 2.5V bypass capacitor ceramic ?
So you think the pll unlocked? That would produce an error, no? I didn’t use a bead. On the new board I’ll use separate analog and digital supplies, as my Psu has both. All my caps are ceramic.
I’m not super worried at this point. My spdif cable is 3m long, and the test setup is a mess of wires. When it’s properly mounted with smaller connectors, it should be better I think
I’m not super worried at this point. My spdif cable is 3m long, and the test setup is a mess of wires. When it’s properly mounted with smaller connectors, it should be better I think
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If I understand correctly, your supplies already have separate regulators for 3.3V and 2.5V. But the HF ripple rejection of an LDO is often next to nothing, which could be the problem. And you'd need the ferrite anyway.
Since the PLL ground is returned to the DGND without the ferrite, its operation could be affected by digital current draw during decoding. You also don't seem to have a filter on the 2.5V supply.
The S/PDIF length should not be a problem as long as the cable is shielded.
Since the PLL ground is returned to the DGND without the ferrite, its operation could be affected by digital current draw during decoding. You also don't seem to have a filter on the 2.5V supply.
The S/PDIF length should not be a problem as long as the cable is shielded.
Yah, I'll add the filter on the next boards. I'll look at adding a ferrite bead too.. I wasn't sure if it was needed. One schematic showed it and another just showed it connecting to AGND directly.