The Rikstone H50 is an AB class amplifier with fixed bias. 
The amplifier part is based on the VOX AC50.

Technical data:

Inputs: 2 x Normal and 2 x Brilliant
Outputs: 16, 8 and 4 Ohm
Controls: GAIN, BASS, TREBLE (Normal channel)
GAIN, BASS, TREBLE (Brilliant channel)
MASTER VOLUME (common)
PT: 230V/360V/250mA/6,3V/4,3A
OT: A transformer for EL34 pair
Rectifier: Diode bridge
Schematics: PowerSupply
PreAmp
PowerAmp
User's Guide: In Finnish only