ProtoDAC TDA1387 X8 project

[hifinet]

I receive requests for kits with "premium components". The kit comes with components of very high quality, that have been carefully chosen for optimal sound quality. The user can upgrade components.

There are no options for the TDA1387 X8 modules. 

The Texas Components TX2575 Z-foil I/V resistors are the highest quality obtainable, and comprise by far the largest percentage of the value of the kit. 

The WIMA MKP4 metallized polypropylene output coupling capacitors are of excellent quality, but potentially could be replaced and sound quality improved. There are active discussions in this thread regarding polycarbonate capacitors. The "silver caps" (CRC) are rare. I see maybe one eBay listing a year. There are many other choices, many would be a matter of personal taste. Mundorf, for example, manufactures many quality capacitors that could be substituted. One could perhaps even use $400 Jupiter caps. There are size restrictions due to the HAT format of the PCB. They should be film capacitors. The value can be between 4.7 to 10uF. The voltage should be the lowest available for a film capacitor, which will reduce size. The PCB can accommodate radial (restricted to 37.5mm lead spacing) or axial capacitors.

This is where I previously shopped for parts. There were vendors who sold milsurp stuff. Maybe you have one near you.

Here is an article rating a bunch of capacitors.

The power supply decoupling capacitors C3/C4 have a significant impact on sound quality in terms of soundstage, imaging and dynamics. I think these are a matter of personal taste as well. So far, I prefer the Panasonic FR (EEU-FR1A102L and EEU-FR1A102LB) . I have tried Nichicon UKA, FG, Elna Silmic II, Audio Note Seiryu and others. There are size limitations on the PCB. Voltage rating should be at least 6.3V. Would Black Gates sound better? I don't know. 

The I2S resistors are generic metal film. Could upgrading the quality of these resistors to "premium" improve sound quality. Honestly, I am not sure.