Version 4 SHEET 1 880 680 WIRE -432 -256 -624 -256 WIRE -176 -256 -432 -256 WIRE 224 -256 -176 -256 WIRE 464 -256 224 -256 WIRE -16 -224 -80 -224 WIRE -176 -176 -176 -256 WIRE -80 -176 -80 -224 WIRE -624 -144 -624 -256 WIRE -432 -128 -432 -256 WIRE 224 -128 224 -256 WIRE 464 -80 464 -256 WIRE -80 -64 -80 -96 WIRE -16 -64 -16 -224 WIRE 112 -64 -16 -64 WIRE -16 -48 -16 -64 WIRE -624 -32 -624 -64 WIRE 224 -32 224 -48 WIRE 416 -32 224 -32 WIRE 112 -16 112 -64 WIRE -176 32 -176 -96 WIRE -432 64 -432 -48 WIRE -352 64 -432 64 WIRE -256 64 -288 64 WIRE -16 64 -16 32 WIRE -80 80 -128 80 WIRE -432 96 -432 64 WIRE -256 96 -256 64 WIRE -224 96 -256 96 WIRE 224 96 224 -32 WIRE -80 112 -80 80 WIRE -576 144 -704 144 WIRE -480 144 -576 144 WIRE 112 144 112 64 WIRE 176 144 112 144 WIRE -256 160 -256 96 WIRE -208 160 -208 144 WIRE -144 160 -208 160 WIRE -208 192 -208 160 WIRE -144 192 -144 160 WIRE 112 192 112 144 WIRE -704 208 -704 144 WIRE -576 208 -576 144 WIRE -464 224 -464 192 WIRE 192 224 192 192 WIRE -704 336 -704 288 WIRE -576 336 -576 288 WIRE -576 336 -704 336 WIRE -464 336 -464 304 WIRE -464 336 -576 336 WIRE -288 336 -464 336 WIRE -256 336 -256 240 WIRE -256 336 -288 336 WIRE -208 336 -208 272 WIRE -208 336 -256 336 WIRE -144 336 -144 256 WIRE -144 336 -208 336 WIRE 112 336 112 272 WIRE 112 336 -144 336 WIRE 192 336 192 304 WIRE 192 336 112 336 WIRE -288 352 -288 336 WIRE -80 368 -80 192 WIRE 432 368 432 16 WIRE 432 368 -80 368 FLAG -288 352 0 FLAG -16 64 0 FLAG -624 -32 0 FLAG -80 -64 0 SYMBOL triode_dd -432 144 R0 WINDOW 38 8 -36 Left 2 SYMATTR InstName U1 SYMATTR SpiceModel 12AX7_ECC83 SYMBOL tetrode_dd -176 80 R0 WINDOW 38 8 -36 Left 2 SYMATTR InstName U2 SYMATTR SpiceModel 6CA7_EL34 SYMBOL res -224 176 R0 SYMATTR InstName R1 SYMATTR Value 400 SYMBOL cap -160 192 R0 SYMATTR InstName C1 SYMATTR Value 100µ SYMBOL ind2 -192 -192 R0 SYMATTR InstName L1 SYMATTR Value 150 SYMATTR Type ind SYMBOL ind2 -96 -192 R0 SYMATTR InstName L2 SYMATTR Value .22 SYMATTR Type ind SYMBOL res -480 208 R0 SYMATTR InstName R2 SYMATTR Value 1.2k SYMBOL res -448 -144 R0 SYMATTR InstName R3 SYMATTR Value 47k SYMBOL cap -288 48 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C3 SYMATTR Value 100n SYMBOL res -32 -64 R0 SYMATTR InstName R4 SYMATTR Value 8 SYMBOL voltage -624 -160 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value 300 SYMBOL res -592 192 R0 SYMATTR InstName R5 SYMATTR Value 100k SYMBOL triode_dd 224 144 R0 WINDOW 38 8 -36 Left 2 SYMATTR InstName U3 SYMATTR SpiceModel 12AX7_ECC83 SYMBOL res 176 208 R0 SYMATTR InstName R6 SYMATTR Value 1.2k SYMBOL res 208 -144 R0 SYMATTR InstName R7 SYMATTR Value 47k SYMBOL voltage -704 192 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V2 SYMATTR Value SINE(0 .5 1000) SYMBOL res 96 176 R0 SYMATTR InstName R8 SYMATTR Value 1000 SYMBOL res 96 -32 R0 SYMATTR InstName R9 SYMATTR Value 10k SYMBOL triode_dd 464 -32 R0 WINDOW 38 8 -36 Left 2 SYMATTR InstName U4 SYMATTR SpiceModel 12AX7_ECC83 SYMBOL res -96 96 R0 SYMATTR InstName R10 SYMATTR Value 100 SYMBOL res -272 144 R0 SYMATTR InstName R11 SYMATTR Value 47k TEXT -552 -296 Left 2 !.tran 1 TEXT -184 -304 Left 2 !K L1 L2 0.9999