1. Circuit design is modified based on the classical Marantz 7C and the component values are optimized.
2. Three 12AX7 vacuum tubes.
3. Use of WIMA / Solen MPK film capacitors, Nichicon Audio capacitors, Philips/BHC Averox capacitors, and Dale resistors.
4. Low voltage dropout regulator LT1085 is employed in regulating power supply for tubes filament, which gives a maximum output driving current of the IC is 3A which is far enough for filament power supply.
5. Dedicated power and ground rails for tube power and tube filaments.
6. Symmetry in layout design for both channels.
7. Power requirement: one 200V AC (100mA) and one 12.6V AC (1A)
8. PCB dimension: 110mmx200mm, thickness 2.5mm and 2oz copper, two layers.
- Voltage gain: 24dB
- Gain flatness: <0.05dB for 20-20KHz
- Frequence response: 20-20KHz
- Input Impedance: 880K Ohms
- Output Impedance: 50K Ohms
- Input Sensitivity: 1.5V RMS
- S/N Ratio > 96dB
- THD+N < 0.01% @1KHz
- Stereo single-end input and output