mivarpet

@barrows The Audio GD R2R-7 DACs have what is called "High Exact" mode on I2S inputs that offer a very precise lock on the input that can only be used with the best sources. Please see this link from Audio GD (about half way down in "2018 version firmware setting guide" - For the HDMI or IIS input, if the sources or transmit cause the signal had not enough good, the sound had noise or distortion, push into the jumper for fixed the issue. I ran the non-isolated version fine for many months with no problems, so I'm not sure if it's a power thing. Would I be correct in saying the isolated version may draw less power as it's partly USB powered? The telling change though was when I put a jumper on the Audio GD, the distortion went so it would appear it's a jitter issue. After I posted, I put the FIFO board back on and the sound quality was restored without any need for the jumper.

@Whitigir I just tried my board without the re-clocker and got the same distorted sound as you. I put the S2 jumper on (to disable the "hi-exact" mode on the input) and the music is playing, but not sounding great. I guess this proves what @barrows mentioned in the previous post. When I had the FIFO module on it was glitching a lot and struggling with 192K audio. Looks like I may go back to the non-isolated version. Sigh.

Thats a shame. What are you driving it with? I have the same digital board as the R2R7 & am running the latest Smooth Accurate firmware The last two nights I’ve had some issues with mine too - sound distorted on some tracks and also playing slow. I had to reset the DAC & source and it came good. I certainly never had that problem with the non-isolated board. I’ll remove the FIFO board and see how that helps. The DIYINHK site says the FIFO board is only good for about 5% improvement on PCM1704 based DACs in any case.

@Whitigir These are the pinouts I used are - Audio GD > XMOS DA > Data BCK > BCK LRCK > LRCK MLCK > MCK GND > GND GND > GND VCC > 3.3V I've also attached some pictures from the board and Audio GD digital board to show you the pins. I'm using a Linux computer to drive the USB, so I don't need drivers. Hope this helps.

@Whitigir I've used both the standard and isolated versions of this board on my Master 7 with the digital board upgrade and it works well. The standard version I felt was better than the Amanero and the isolated version even better still. Did your USB cable have straight through power? I believe the USB input side of the module needs USB power as the 3V3 power to the module is only for the isolated side. I can send you pin outs tonight when I get home.

Classic response :-) Thanks!

@paulinus - thanks for letting us know about the mods. Most importantly - what was the impact of the mods? Thanks!