I²S input board
Here is a I²S input board from Audio-GD that I modified to replace the existing USB input board on the Pavane so that it can accept I²S.
Since I²S transmission removes the need for a receiver chip and reconversion, I found it to sound significantly better than all other inputs such as USB, S/PDIF, or even AES/EBU. To me, the Metrum Acoustics Pavane sounds better than the Holo Audio Spring that I once upgraded from. The inconvenience here is that the Spring had this input whereas the Pavane didn't. For a long time I wondered how much better the Pavane would sound if it could utilize this type of input. Now the question has been answered. It sounds much better in a way where digital characteristics of sound is removed and this unit now sounds more lifelike than it ever has before.
The Technicals
An ultra-low noise VISHAY/DALE 165Ω resistor (CMF55/RN55) was added to the Audio-GD board to drop the incoming voltage (5.47V) that was once used to power USB input board to a working 3.3V for the I²S input board. Audio-GD's stock "Nover" electrolytic capacitors were replaced with better performing solid polymer Nichicon R7 for faster discharging (lower ESR) in case time variable becomes an important factor with I²S signals. The upgraded capacitors was too large for the space available hence one of them was mounted to the opposite side of the board. The bottom wires (Ground, +3.3V, SCLK, WCLK, and DATA) are soldered each to a female dupont connector and bent to a right angle so that they can fit without hitting the board when connected to the existing header pins (used for the previous USB Input board). I roughly measured the wires, soldered it, and adjusted it to where it would need to make proper contact with the pins all-while minimizing the length to prevent additional induced jitter (caused by longer wire runs).
Board Installation