1. Circuit design is modified based on the classical Marantz 7C and the component values are optimized.
2. Output stage is changed to 12AU7 SRPP to provide wide bandwidth and low distortion
3. Two 12AX7 and two 12AU7 vacuum tubes.
4. Use of WIMA / Solen MPK film capacitors, Nichicon Audio capacitors, BHC Averox / Philip BC capacitors, and Dale resistors. 5. Low voltage dropout regulator LT1085 is used to provide regulated power for tubes filament, which gives a maximum output driving current of the IC is 3A which is far enough for filament power supply.
6. Dedicated power and ground rails for tube power and tube filaments.
7. Symmetry in layout design for both channels.