[Mondial]

I would not sub a 112A for a 71A. The bias requirements are totally different. The 112A requires only -13.5 V bias while the 71A needs -40V. Subbing 112A's will throw off all the bias voltages since they are mainly determined by the current drain of the 71A output stage.

The 112A is actually a 201A battery set tube with an oxide coated filament. Its not really designed for use as an audio output tube.

Hope this helps.