Details
New old stock triode on engraved standard 4 pin base. Western Electric brand. This is electrically identical to the 231D, except it has the grid out the top and is controlled for microphonics.
New old stock triode on engraved standard 4 pin base. Western Electric brand. This is electrically identical to the 231D, except it has the grid out the top and is controlled for microphonics.