Version 4
SHEET 1 880 680
WIRE -1600 -160 -1680 -160
WIRE -1520 -160 -1600 -160
WIRE -1360 -128 -1360 -160
WIRE -1360 -128 -1440 -128
WIRE -1280 -128 -1360 -128
WIRE -1440 -80 -1440 -128
WIRE -1280 -80 -1280 -128
WIRE -1520 -64 -1520 -80
WIRE -1680 -48 -1680 -80
WIRE -1520 -48 -1520 -64
WIRE -1520 32 -1520 16
WIRE -1488 32 -1520 32
WIRE -1440 32 -1440 -16
WIRE -1440 32 -1488 32
WIRE -1280 32 -1280 -16
WIRE -1280 32 -1360 32
WIRE -1168 32 -1280 32
WIRE -1152 32 -1168 32
FLAG -1360 -160 0
FLAG -1680 -48 0
FLAG -1168 32 Bias
FLAG -1600 -160 1
FLAG -1520 -64 2
FLAG -1488 32 3
SYMBOL cap -1456 -80 R0
WINDOW 0 -18 7 Left 2
WINDOW 3 -26 56 Left 2
SYMATTR InstName C1
SYMATTR Value 10µ
SYMATTR SpiceLine V=100
SYMBOL cap -1296 -80 R0
SYMATTR InstName C2
SYMATTR Value 10µ
SYMATTR SpiceLine V=100
SYMBOL diode -1504 16 R180
WINDOW 0 37 36 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName Rectifier
SYMATTR Value 1N4007
SYMBOL res -1344 16 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 15k
SYMATTR SpiceLine pwr=.5
SYMBOL res -1376 -144 R0
SYMATTR InstName R3
SYMATTR Value 27k
SYMBOL res -1376 -64 R0
SYMATTR InstName Pot
SYMATTR Value 29K
SYMBOL voltage -1680 -176 R0
WINDOW 0 -224 8 Left 2
WINDOW 3 -183 103 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName 325V.AC.RMS.60Hz
SYMATTR Value SINE(0 460 60)
SYMBOL res -1536 -176 R0
WINDOW 0 -30 35 Left 2
WINDOW 3 -58 71 Left 2
SYMATTR InstName R1
SYMATTR Value 220K
TEXT -1832 184 Left 2 !.MODEL 1N4007 D(Rs=0.010 Tt=2u Cjo=15p Vj=0.6 BV=1000 Ibv=5u)
TEXT -1832 208 Left 2 !.tran 0 7s 0s .1s startup
TEXT -1552 128 Center 2 ;325V AC RMS In, no grid current, 50K bias pot set to 29K + 27K = 56K total resistance.
TEXT -1568 -232 Center 4 ;Universal HT Tap Tube Amp Fixed Bias Circuit
TEXT -2024 -120 Left 2 ;325V AC RMS = 460V Peak
TEXT -1896 208 Right 1 ;By Rob Robinette
TEXT -1168 48 Center 1 ;To power tube\ngrid leak resistors