LCLC PS for the 2A3, (can be even simpler, say CLC :-)), plus RC stage for the driver tube. Driver tube has CCS load (can be anode choke as well). P is hum-cancelling pot, cathode bias is from Rk (+Ck bypass). I ommited "standby" switch (for pre-heating).
For the 2A3 values of the output stage are:
R3=220k, R4=1 kOhms, P=50 Ohms/2W, Rk2=750 Ohms/10W, Ck2=47-100 uF/100V, trafo Ra=2k5, B+ = 300V.
V1 and the components - depends of the tube used (we`ll see), the same as of V3/secondary /Ufv3 voltage/current.
Ufv2 is 2,5V/2,5A and Uhv1=6,3V/1A.