Anode is connected via top cap — not available on the octal base pins.
Pin 3 is unused (no connection). Suppressor grid (g3) is on pin 6, which differs from the EL38 where g3 is on pin 1.
4654K is the octal-based variant and is pin-compatible with the EL39.
EL50 and 4654 (P8A base) are sometimes listed as equivalents but have different ratings — they are not direct substitutes.
For push-pull stages, it is inadvisable to employ high anode voltages unless the grid bias is fixed.
The 4654 datasheet specifies a maximum anode voltage of 600V; the EL50 datasheet shows operation at 800V. Use 600V as the safe maximum unless the specific tube variant is confirmed as EL50-rated.