[Myrdin]

Ahoy,
 
I recently came across a box of the Raytheon 717A tubes. A simple pentode synonymous with the VT-269 tube. Though I know it's not good criteria for selection I love their appearance: A smooth flattened bulb with a sideways plate assembly in the middle (picture below). Looking up the datasheets they seem vaguely similar to half a 12AX7 tube. 
http://frank.pocnet.net/sheets/127/7/713A.pdf
Does anyone have any experience with these tubes, or possibly guidance/schematics on implementing them in a headphone amplifier? The only use I've seen in an audio amp so far is the Yamamoto A08 and all their products are an order of magnitude over my budget. I can assemble amps but the finer parts of design are far above my skill level.
 
Much obliged.

 

[duncan1]

These date from the early 50s. Were used by government in equipment supplied to them at the time as space saving. The anode[plate ] current is very low-7.5MA even in push-pull you wont get much amplification[power gain] out of them Plate Voltage 120. May look nice and I have some UK versions but require specialized circuit for them.