R50MKII is a 20dB gain line stage pre-amplifier using improved SRPP circuit with no global negative feedback.
The capacitors used for signal coupling is the exotic US AuriCap. All connections are point to point wiring using high purity copper hook up wire. The circuit board acts as a support frame for the tubes and other components and actual point to point wirings are done beneath the circuit board.
The power transformer and choke are shielded from the circuit board. A special silicon steel EI type power transformer and choke with good high frequency response is used together with large Solen MKP metallized polypropylene filtering capacitor.
Read UK's HiFi+ magazine review here.