The circuit design is referenced to the Conrad John and the values are adjusted and optimized. The input stage uses 12AX7in common cathode, whereas the output stage uses 12AT7. The signal paths of this PCB layout are designed in symmetry for both channels. Dedicated power rails, ground, and signal paths, altogether are taken into designconsiderations so that all are to minimize the parasitic, cross interference, and influence of RFI.
One 12AX7 and one 12AT7 vacuum tubes.
Voltage gain: 26dB
Frequency Flatness: 20-20KHz (+/-0.6dB)
S/N Ratio: >94dB
THD: 0.057% @Vin = -10dBm and 1KHz
0.087% @Vin= -6.4dBm and 1KHz
Input impedance 1M Ohm
Output impedance 3K Ohm
Two single-ended and two single-ended outputs.
Symmetric layout design and signal paths with minimum parasitic.
Dedicated ground and power rails layout design.
Two large reservoir decoupling capacitors for power rails.
Power requirements: one 260V (10mA) DC, and one 12.6V (0.5A) DC.