Here is an amp I built several years ago. The choke is by Electra Print although any choke with 100H at 15mA will work. Naturally the choke DCR will become part of the computation for the 2A3 bias resistor. This amp uses the 6N23P which works fine, but I found it far inferior in sound quality to the triode connected E180F (I am traveling and don't have the most recent schematics with me). So to build this amp you will have to be able to compute the two resistors in the cathode of the 2A3 to ensure both the 6N23P and 2A3 work in their most linear region.
The amount of current through each resistor is marked on the schematic also notice that the voltages dropped by the resistors are marked on the schematic. Multiply the voltage by the current to get the wattage and then double that amount for safety.