I think it would be best to decrease that I/V resistor as much as possible, as long as there is enough gain from the circuit. Distortion of the DAC will reduce with a lower I/V resistance, and it's always best not to amplify distortion. Also speculating that a metal foil (TX2575) resistor would be of value there.
Regarding a tube DAC for a CD transport, the inexpensive DIR9001 boards (SPDIF to I2S) work very well, in my experience.
Regarding a tube DAC for a CD transport, the inexpensive DIR9001 boards (SPDIF to I2S) work very well, in my experience.
Hardware: RPi Zero W | Allo Kali | ProtoDAC TDA1387 X8 | PGA2311 | Icepower 500ASP | Harbeth SHL5
Software: Moode 8.3.3
Source: Win 10 NAS
Software: Moode 8.3.3
Source: Win 10 NAS