The design of this preamplifier is based on CAT SL-1 preamplifier and the design values are optimized. By using three tube stages:12AU7, 12AX7 and 6DJ8; The first-stage use 12AU7which is denoted with high-bandwidth and providing sweet sound. The second stage is even more amazing; the use of high-magnification tube 12AX7 in SRPP configuration, it can create extremely broad bandwidth and ultra dynamic. Finally, the output is done by using 6DJ8 to obtain very low output impedance and increase the driving capability. The output voltage swing can be reach more than 50V.
1. One 12AU7, two 12AX7, and one 6DJ8.
2. First two amplification stages consist of 12AU7 in common cathode and then 12AX7 in SRPP. The final stage are cathode follower provided by 6DJ8
3. Two single-ended inputs and two single-ended outputs.
4. Symmetric layout design and signal paths with minimum parasitic.
5. Dedicated ground and power rails layout design.
6. Four large reservoir decoupling capacitors for power rails.
7. Power requirements: one 260V DC, one 12.6V DC, and one 6.3V AC.