NGspice requires a real title. A blank line won't do. .model zz npn bf=150 .subckt foo (vcc in out) q1 (c b e 0) zz Rc (c vcc) 10k Re (e 0) 1k Rb1 (b vcc) 100k Rb2 (b 0) 10k Cin (b in) 1u Cout (c out) 1u Rin (in 0) 100k Rout (out 0) 100k .ends Vcc (V_cc 0) dc 20 Vin (in 0) ac .1 X1 (V_cc in out) foo *>.print op v(nodes) vbc(q1.*) .op .print ac v(in) v(out) .ac dec 1 1k 10k .end