circuitjs for converting balanced audio into single-ended biased around 1.65v and remove noise.

WORKS_annotated_impedance_balanced_to_single_ended_positive-only-op-amp_exactly_1pt65v_capacitively-biased_circuit-20220328.circuitjs.txt

$ 65 1e-8 263.0686190299136 63 5 43 5e-11
w -496 208 -336 208 0
w -496 384 -336 384 0
b -809 125 -356 485 0
x -796 79 -578 82 4 12 Model\sof\show\sthe\sbalanced\saudio\scomes:
x -797 101 -436 104 4 8 •\s60\sHz\snoise\s(B)\sfrom\spower\slines\sgets\sadded\sin\sphase\sto\soriginal\ssignal\s(A)\sand\sto\sinverse\ssignal\s(-A).
209 -128 384 -208 384 0 0.000009999999999999999 1.6190470112865065 1.65 0.1
209 -128 208 -208 208 0 0.000009999999999999999 1.6505183937354877 1.65 0.1
212 -624 208 -576 208 0 2 a\pb
g -528 416 -528 448 0 0
g -528 240 -528 272 0 0
w -672 384 -672 208 0
w -688 320 -688 416 0
w -688 416 -656 416 0
w -688 320 -688 240 0
w -688 240 -656 240 0
403 -480 208 -368 272 0 0_16_0_135170_1.25_0.1_-1_2_0_3
403 -480 304 -368 368 0 1_16_0_135170_1.25_0.1_-1_2_1_3
212 -624 384 -576 384 0 2 -a\pb
x -761 201 -664 204 4 12 A\sis\sdesired\ssignal
x -803 443 -639 446 4 12 B\sis\sundesired\snoise\sto\sremove
r 256 384 160 384 0 50500
w 336 288 352 288 0
403 336 208 560 288 0 21_16_0_x121102_5_0.000390625_-1_2_21_3
w 160 384 160 304 0
w 256 384 256 288 0
w 160 208 160 272 0
x -600 351 -545 354 4 12 V\s\q\s-A\s\p\sB
x -604 175 -553 178 4 12 V\s\q\sA\s\p\sB
b -193 175 -140 407 0
x -193 145 -129 148 4 12 AC\scoupling
x -191 154 -141 157 4 8 Big\scapacitors
x -191 171 -121 174 4 8 •\swhile\sisolating\sDC.
x -644 185 -532 188 4 8 original\ssignal\s(A)\splus\snoise\s(B)
x -639 363 -524 366 4 8 inverse\ssignal\s(-A)\splus\snoise\s(B)
x -192 162 -118 165 4 8 •\spasses\saudio\sfreqs.
x -135 103 -46 106 4 8 •\sCenter\sinputs\s(\a\soutput)
x -465 202 -381 205 4 8 signal\s(A)\splus\snoise\s(B)
x -486 378 -371 381 4 8 inverse\ssignal\s(-A)\splus\snoise\s(B)
x -132 95 -40 98 4 12 1.65v\sDC\sBiasing
v -752 416 -688 416 0 6 40 0.1 0 0 0.5
w -752 208 -672 208 0
R -752 384 -784 384 0 3 60 0.5 0 0 0.5
R -752 208 -784 208 0 3 3506.5 0.76 0 0 0.5
s -656 384 -624 384 0 0 false
s -656 208 -624 208 0 0 false
s -656 416 -624 416 0 0 false
s -656 240 -624 240 0 0 false
w -672 384 -656 384 0
w -672 208 -656 208 0
O 384 288 544 288 0 0
r -528 208 -496 208 0 50
r -528 384 -496 384 0 50
x -802 461 -737 464 4 8 •\splus\swhite\sNoise.
x 319 152 449 155 4 24 clean\soutput
x 323 166 446 169 4 8 •\stwice\soriginal\ssignal:\sA\s-\s(-A)\s\q\s2A
x 325 176 435 179 4 8 •\swithout\sany\snoise:\sB\s-\s(-B)\s\q\s0
x 325 184 456 187 4 8 •\scentered\saround\sVhalf_bias:\s\p1.65v
x -802 451 -677 454 4 8 •\sharmonics\sfrom\s60\sHz\spower\slines
x -797 90 -424 93 4 8 •\sSignal\s(A)\sis\swhat\sis\sdesired.\s\sA\sis\ssent\sin\sboth\sregular\sand\sinverted\sform,\sbut\salong\swith\sundesired\snoise.
x -797 112 -480 115 4 8 •\sThere\sis\ssome\soutput\simpedance\sand\sresistance\salong\sthe\swire\sI've\sgrouped\sas\s500\sohm
c -336 208 -336 272 0 1e-9 -0.7381283997450289 0
w -336 208 -272 208 0
g -336 272 -336 288 0 0
g -336 448 -336 464 0 0
c -336 384 -336 448 0 1e-9 0.7379074857650534 0
w -336 384 -272 384 0
c 288 464 288 384 0 4.7e-12 -0.19354673065438946 0
g 288 464 288 480 0 0
w -64 384 0 384 0
w -96 208 64 208 0
w -64 384 -128 384 0
x 397 330 633 333 4 12 Clipping\sdiodes\sprotect\s3.3v\smicrocontrollers
b 666 415 366 314 0
w 256 384 288 384 0
b 334 495 258 410 0
x 242 505 344 508 4 12 Remove\sMhz\snoise
x 101 164 207 167 4 24 subtractor
x 324 194 434 197 4 8 •\sclipped\sto\srange\sof\s0V\sto\s3.3V
x 325 203 519 206 4 8 •\sno\snoticible\sdistorition\sbetween\s0.15\sV\sto\s3.15\sV\sor\sso
x -354 192 -282 195 4 8 filter\scellphone\snoise
b -354 197 -281 482 0
x -237 61 629 64 4 28 Convert\sBalanced\sAudio\sto\srange\sof\s0v\sto\s3.3v,\scentered\saround\s1.65v
x 400 340 660 343 4 8 •\sred\sLED\sturn\son\sslowly\sto\sindicate\sgetting\sclose,\sand\sbright\swhen\sexceed
w 384 304 384 288 0
g 384 432 384 448 0 0
x 400 349 662 352 4 8 •\sin\sseries\swith\s2.0v\sZener\sdiode\sas\ssecondary\sprotection\sto\shard\scut\s>3.3v
w 384 288 352 288 0
x 75 175 240 178 4 8 •\sremoves\snoise\s(B)\swhile\spreserving\ssignal\s(A)
w 112 208 160 208 0
w 0 384 32 384 0
34 fwdrop\q2 1 9.32e-11 0 3.3479240811663615 0 1
162 -96 208 -96 240 2 fwdrop\q2 0 1 0 0.01
162 -96 176 -96 208 2 fwdrop\q2 0 1 0 0.01
34 zener-2 1 1.7143528192810002e-7 0 2.0000000000000084 2 1
z 384 432 384 368 2 zener-2
34 fwdrop\q1.6 1 9.32e-11 0 2.6783392649330895 0 1
162 384 304 384 368 2 fwdrop\q1.6 1 0 0 0.01
x -135 110 -20 113 4 8 •\sLED\sturns\son\swhen\ssignal\sinput
x -135 118 30 121 4 8 •\sLED\sbrightness\sindicates\show\sstrong\ssignal\sis
g 208 320 208 336 0 0
r 160 384 64 384 0 50500
w 32 384 64 384 0
w -272 208 -240 208 0
w -208 208 -240 208 0
w -272 384 -240 384 0
w -240 384 -208 384 0
r 64 208 112 208 0 50500
w -528 224 -496 224 0
w -496 416 -464 416 0
w -768 336 -704 336 0
g -752 416 -768 416 0 0
r 112 208 112 256 0 50500
209 112 256 112 288 0 0.000009999999999999999 1.6491060893706375 1.65 0.1
g 112 288 112 304 0 0
w -128 208 -96 208 0
g -96 288 -96 304 0 0
r -96 240 -96 288 0 3970
R -96 128 -112 128 0 0 40 3.3 0 0 0.5
r -96 128 -96 176 0 3970
w 336 288 304 288 0
r 256 288 304 288 0 130
409 160 288 256 288 3 0.6 0 0.023100000000000002 2
R 208 256 224 256 0 0 40 5 0 0 0.5
o 49 8 0 x123102 3.0664396061001256 0.0001 0 3 23 3 25 3
38 42 F1 0 0 2 -1 Max\sVoltage
38 42 F1 3 10 10000 -1 Frequency
38 97 F1 0 1000 100000 -1 bottom-resistance
38 103 F1 0 1000 100000 -1 top-resistance
38 115 F1 0 1000 100000 -1 green-LED-resistance
38 113 F1 0 1000 100000 4 \0
38 20 F1 0 1000 100000 2 \0
38 108 F1 0 1000 100000 3 \0

rev 8 uses shared sliders for resistors: