ReVox.sch

EESchema Schematic File Version 4
EELAYER 30 0
EELAYER END
$Descr A3 16535 11693
encoding utf-8
Sheet 1 1
Title "ReVox"
Date "2023-11-17"
Rev "1git"
Comp "SukkoPera"
Comment1 "Based on work by Yeo Kheng Meng"
Comment2 "Licensed under CC BY-NC-SA 4.0"
Comment3 ""
Comment4 ""
$EndDescr
Text Notes 9845 970  0    50   ~ 0
CHIP-SELECT GENERATION\n(INSPIRED BY SOLDER'S SIDCARD)
Wire Wire Line
	13550 2650 13085 2650
Text Label 13085 2650 0    50   ~ 0
latch_clk
Wire Wire Line
	13550 2750 13085 2750
Text Notes 13805 1025 0    50   ~ 0
DATA LATCH
Wire Wire Line
	1890 1675 1785 1675
Wire Wire Line
	1785 1675 1785 4075
Wire Wire Line
	1890 4075 1785 4075
Connection ~ 1785 4075
Wire Wire Line
	1785 4075 1785 4325
$Comp
L power:GND #PWR09
U 1 1 64655433
P 1785 4325
F 0 "#PWR09" H 1785 4075 50  0001 C CNN
F 1 "GND" H 1790 4152 50  0000 C CNN
F 2 "" H 1785 4325 50  0001 C CNN
F 3 "" H 1785 4325 50  0001 C CNN
	1    1785 4325
	1    0    0    -1  
$EndComp
Wire Wire Line
	3390 1675 3495 1675
Wire Wire Line
	3495 1675 3495 4075
Wire Wire Line
	3390 4075 3495 4075
Connection ~ 3495 4075
Wire Wire Line
	3495 4075 3495 4325
$Comp
L power:GND #PWR010
U 1 1 646567C8
P 3495 4325
F 0 "#PWR010" H 3495 4075 50  0001 C CNN
F 1 "GND" H 3500 4152 50  0000 C CNN
F 2 "" H 3495 4325 50  0001 C CNN
F 3 "" H 3495 4325 50  0001 C CNN
	1    3495 4325
	-1   0    0    -1  
$EndComp
Wire Wire Line
	1890 1775 1685 1775
Wire Wire Line
	1685 1775 1685 1300
$Comp
L power:+5V #PWR08
U 1 1 64657FFD
P 1685 1300
F 0 "#PWR08" H 1685 1150 50  0001 C CNN
F 1 "+5V" H 1700 1473 50  0000 C CNN
F 2 "" H 1685 1300 50  0001 C CNN
F 3 "" H 1685 1300 50  0001 C CNN
	1    1685 1300
	1    0    0    -1  
$EndComp
Wire Wire Line
	1890 1875 1685 1875
Wire Wire Line
	1685 1875 1685 1775
Connection ~ 1685 1775
Wire Wire Line
	3390 2175 3735 2175
Wire Wire Line
	3390 2275 3735 2275
Wire Wire Line
	3390 2375 3735 2375
Wire Wire Line
	3390 2475 3735 2475
Wire Wire Line
	3390 2575 3735 2575
Wire Wire Line
	3390 2675 3735 2675
Wire Wire Line
	3390 2775 3735 2775
Wire Wire Line
	3390 2875 3735 2875
Wire Wire Line
	3390 2975 3735 2975
Wire Wire Line
	3390 3075 3735 3075
Wire Wire Line
	3390 3175 3735 3175
Wire Wire Line
	3390 3275 3735 3275
Wire Wire Line
	3390 3375 3735 3375
Wire Wire Line
	3390 3475 3735 3475
Wire Wire Line
	3390 3575 3735 3575
Wire Wire Line
	3390 3675 3735 3675
Entry Wire Line
	3735 2175 3835 2275
Entry Wire Line
	3735 2275 3835 2375
Entry Wire Line
	3735 2375 3835 2475
Entry Wire Line
	3735 2475 3835 2575
Entry Wire Line
	3735 2575 3835 2675
Entry Wire Line
	3735 2675 3835 2775
Entry Wire Line
	3735 2775 3835 2875
Entry Wire Line
	3735 2875 3835 2975
Entry Wire Line
	3735 2975 3835 3075
Entry Wire Line
	3735 3075 3835 3175
Entry Wire Line
	3735 3175 3835 3275
Entry Wire Line
	3735 3275 3835 3375
Entry Wire Line
	3735 3375 3835 3475
Entry Wire Line
	3735 3475 3835 3575
Entry Wire Line
	3735 3575 3835 3675
Entry Wire Line
	3735 3675 3835 3775
Wire Bus Line
	3835 3775 4360 3775
Text Label 4360 3775 2    50   ~ 0
address_bus
Text Label 3735 2175 2    50   ~ 0
a15
Text Label 3735 2275 2    50   ~ 0
a14
Text Label 3735 2375 2    50   ~ 0
a13
Text Label 3735 2475 2    50   ~ 0
a12
Text Label 3735 2575 2    50   ~ 0
a11
Text Label 3735 2675 2    50   ~ 0
a10
Text Label 3735 2775 2    50   ~ 0
a9
Text Label 3735 2875 2    50   ~ 0
a8
Text Label 3735 2975 2    50   ~ 0
a7
Text Label 3735 3075 2    50   ~ 0
a6
Text Label 3735 3175 2    50   ~ 0
a5
Text Label 3735 3275 2    50   ~ 0
a4
Text Label 3735 3375 2    50   ~ 0
a3
Text Label 3735 3475 2    50   ~ 0
a2
Text Label 3735 3575 2    50   ~ 0
a1
Text Label 3735 3675 2    50   ~ 0
a0
Wire Wire Line
	1890 2975 1615 2975
Wire Wire Line
	1890 3075 1615 3075
Wire Wire Line
	1890 3175 1615 3175
Wire Wire Line
	1890 3275 1615 3275
Wire Wire Line
	1890 3375 1615 3375
Wire Wire Line
	1890 3475 1615 3475
Wire Wire Line
	1890 3575 1615 3575
Wire Wire Line
	1890 3675 1615 3675
Entry Wire Line
	1515 3075 1615 2975
Entry Wire Line
	1515 3175 1615 3075
Entry Wire Line
	1515 3275 1615 3175
Entry Wire Line
	1515 3375 1615 3275
Entry Wire Line
	1515 3475 1615 3375
Entry Wire Line
	1515 3575 1615 3475
Entry Wire Line
	1515 3675 1615 3575
Entry Wire Line
	1515 3775 1615 3675
Wire Bus Line
	1515 3775 1105 3775
Text Label 1105 3775 0    50   ~ 0
data_bus
Wire Wire Line
	1890 3975 1510 3975
Text Label 1510 3975 0    50   ~ 0
phi2
Wire Wire Line
	1890 2075 1510 2075
Text Label 1510 2075 0    50   ~ 0
r_~w
Wire Wire Line
	3390 1875 3835 1875
Text Label 3835 1875 2    50   ~ 0
~reset
Text Label 1615 2975 0    50   ~ 0
d7
Text Label 1615 3075 0    50   ~ 0
d6
Text Label 1615 3175 0    50   ~ 0
d5
Text Label 1615 3275 0    50   ~ 0
d4
Text Label 1615 3375 0    50   ~ 0
d3
Text Label 1615 3475 0    50   ~ 0
d2
Text Label 1615 3575 0    50   ~ 0
d1
Text Label 1615 3675 0    50   ~ 0
d0
Text Notes 2310 1055 0    50   ~ 0
INTERFACE TO C16
Text Notes 1435 9020 0    50   ~ 0
DECOUPLING & POWER
$Comp
L Logic_Programmable:PAL20L8 U1
U 1 1 6380AE65
P 10465 2285
F 0 "U1" H 10685 3090 50  0000 C CNN
F 1 "GAL20V8" H 10685 1575 50  0000 C CNN
F 2 "Package_DIP:DIP-24_W7.62mm_Socket_LongPads" H 10465 2285 50  0001 C CNN
F 3 "" H 10465 2285 50  0001 C CNN
F 4 "556-AF22LV10CQZ-30PU" H 10465 2285 50  0001 C CNN "MouserPN"
F 5 "Or buy an old GAL22V10 from AliExpress" H 10465 2285 50  0001 C CNN "Notes"
	1    10465 2285
	1    0    0    -1  
$EndComp
Wire Wire Line
	10465 3085 10465 3160
$Comp
L power:GND #PWR018
U 1 1 6380C937
P 10465 3160
F 0 "#PWR018" H 10465 2910 50  0001 C CNN
F 1 "GND" H 10470 2987 50  0000 C CNN
F 2 "" H 10465 3160 50  0001 C CNN
F 3 "" H 10465 3160 50  0001 C CNN
	1    10465 3160
	1    0    0    -1  
$EndComp
Wire Wire Line
	10465 1385 10465 1275
$Comp
L power:+5V #PWR017
U 1 1 638263B0
P 10465 1275
F 0 "#PWR017" H 10465 1125 50  0001 C CNN
F 1 "+5V" H 10480 1448 50  0000 C CNN
F 2 "" H 10465 1275 50  0001 C CNN
F 3 "" H 10465 1275 50  0001 C CNN
	1    10465 1275
	1    0    0    -1  
$EndComp
Wire Wire Line
	9965 2385 9465 2385
Wire Wire Line
	9965 2285 9465 2285
Wire Wire Line
	9965 2185 9465 2185
Wire Wire Line
	9965 2085 9465 2085
Wire Wire Line
	9965 1985 9465 1985
Wire Wire Line
	9965 1885 9465 1885
Wire Wire Line
	9965 1785 9465 1785
Wire Wire Line
	9965 1685 9465 1685
Wire Wire Line
	9965 1585 9465 1585
Entry Wire Line
	9365 2285 9465 2385
Entry Wire Line
	9365 2185 9465 2285
Entry Wire Line
	9365 2085 9465 2185
Entry Wire Line
	9365 1985 9465 2085
Entry Wire Line
	9365 1885 9465 1985
Entry Wire Line
	9365 1785 9465 1885
Entry Wire Line
	9365 1685 9465 1785
Entry Wire Line
	9365 1585 9465 1685
Entry Wire Line
	9365 1485 9465 1585
Text Label 9465 2385 0    50   ~ 0
a4
Text Label 9465 2285 0    50   ~ 0
a6
Text Label 9465 2185 0    50   ~ 0
a8
Text Label 9465 2085 0    50   ~ 0
a10
Text Label 9465 1985 0    50   ~ 0
a11
Text Label 9465 1885 0    50   ~ 0
a12
Text Label 9465 1785 0    50   ~ 0
a13
Text Label 9465 1685 0    50   ~ 0
a14
Text Label 9465 1585 0    50   ~ 0
a15
Wire Wire Line
	9965 2585 9465 2585
Wire Wire Line
	9965 2485 9465 2485
Entry Wire Line
	9365 2485 9465 2585
Entry Wire Line
	9365 2385 9465 2485
Text Label 9465 2585 0    50   ~ 0
a0
Text Label 9465 2485 0    50   ~ 0
a2
Wire Wire Line
	9965 2785 9465 2785
Wire Wire Line
	9965 2885 9465 2885
Text Label 9465 2785 0    50   ~ 0
phi2
Wire Wire Line
	11465 2285 10965 2285
Wire Wire Line
	11465 2185 10965 2185
Text Label 11465 2185 2    50   ~ 0
a1
Wire Wire Line
	10965 1585 11465 1585
Wire Wire Line
	10965 1685 11465 1685
Wire Wire Line
	10965 1885 11465 1885
Text Label 9465 2885 0    50   ~ 0
~reset
Text Label 8865 1485 0    50   ~ 0
address_bus
Wire Bus Line
	9360 1485 8865 1485
Text Notes 10525 3115 0    50   ~ 0
OR GAL22V16
$Comp
L power:+5V #PWR024
U 1 1 63D3BF6E
P 14050 1295
F 0 "#PWR024" H 14050 1145 50  0001 C CNN
F 1 "+5V" H 14065 1468 50  0000 C CNN
F 2 "" H 14050 1295 50  0001 C CNN
F 3 "" H 14050 1295 50  0001 C CNN
	1    14050 1295
	-1   0    0    -1  
$EndComp
$Comp
L power:GND #PWR025
U 1 1 63E509B2
P 14050 3145
F 0 "#PWR025" H 14050 2895 50  0001 C CNN
F 1 "GND" H 14055 2972 50  0000 C CNN
F 2 "" H 14050 3145 50  0001 C CNN
F 3 "" H 14050 3145 50  0001 C CNN
	1    14050 3145
	-1   0    0    -1  
$EndComp
Entry Wire Line
	14940 1850 14840 1750
Entry Wire Line
	14940 1950 14840 1850
Entry Wire Line
	14940 2050 14840 1950
Entry Wire Line
	14940 2150 14840 2050
Entry Wire Line
	14940 2250 14840 2150
Entry Wire Line
	14940 2350 14840 2250
Entry Wire Line
	14940 2450 14840 2350
Entry Wire Line
	14940 2550 14840 2450
Wire Bus Line
	14940 2550 15575 2550
Text Label 15575 2550 2    50   ~ 0
digital_audio
Wire Wire Line
	13550 1750 13085 1750
Wire Wire Line
	13550 1850 13085 1850
Wire Wire Line
	13550 1950 13085 1950
Wire Wire Line
	13550 2050 13085 2050
Wire Wire Line
	13550 2150 13085 2150
Wire Wire Line
	13550 2250 13085 2250
Wire Wire Line
	13550 2350 13085 2350
Wire Wire Line
	13550 2450 13085 2450
Entry Wire Line
	12985 1850 13085 1750
Entry Wire Line
	12985 1950 13085 1850
Entry Wire Line
	12985 2050 13085 1950
Entry Wire Line
	12985 2150 13085 2050
Entry Wire Line
	12985 2250 13085 2150
Entry Wire Line
	12985 2350 13085 2250
Entry Wire Line
	12985 2450 13085 2350
Entry Wire Line
	12985 2550 13085 2450
Wire Bus Line
	12985 2550 12575 2550
Text Label 12575 2550 0    50   ~ 0
data_bus
Text Label 13085 1750 0    50   ~ 0
d0
Text Label 13085 1850 0    50   ~ 0
d1
Text Label 13085 1950 0    50   ~ 0
d2
Text Label 13085 2050 0    50   ~ 0
d3
Text Label 13085 2150 0    50   ~ 0
d4
Text Label 13085 2250 0    50   ~ 0
d5
Text Label 13085 2350 0    50   ~ 0
d6
Text Label 13085 2450 0    50   ~ 0
d7
$Comp
L void:Void V0
U 1 1 64272105
P 11000 11025
F 0 "V0" H 11078 11071 50  0000 L CNN
F 1 "LOGO" H 11078 10980 50  0000 L CNN
F 2 "ReVox:logo" H 11000 11025 50  0001 C CNN
F 3 "" H 11000 11025 50  0001 C CNN
F 4 "-" H 11000 11025 50  0001 C CNN "MouserPN"
	1    11000 11025
	1    0    0    -1  
$EndComp
$Comp
L void:Void V1
U 1 1 64272908
P 11000 10800
F 0 "V1" H 11078 10846 50  0000 L CNN
F 1 "CC-BY-NC-SA" H 11078 10755 50  0000 L CNN
F 2 "ReVox:cc_by_nc_sa" H 11000 10800 50  0001 C CNN
F 3 "" H 11000 10800 50  0001 C CNN
F 4 "-" H 11000 10800 50  0001 C CNN "MouserPN"
	1    11000 10800
	1    0    0    -1  
$EndComp
Wire Wire Line
	10965 1985 11465 1985
Text Label 11465 1985 2    50   ~ 0
a5
Text Label 11465 1885 2    50   ~ 0
a7
$Comp
L Device:R R1
U 1 1 64A62418
P 1755 6215
F 0 "R1" H 1825 6261 50  0000 L CNN
F 1 "22k" H 1825 6170 50  0000 L CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 1685 6215 50  0001 C CNN
F 3 "~" H 1755 6215 50  0001 C CNN
F 4 "603-MFR-25FTE52-22K" H 1755 6215 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly TWICE R3, etc. Range is 1k-100k. Use 1% or even better." H 1755 6215 50  0001 C CNN "Notes"
	1    1755 6215
	1    0    0    -1  
$EndComp
Wire Wire Line
	1755 6365 1755 6485
Wire Wire Line
	1755 6485 1965 6485
Connection ~ 1755 6485
$Comp
L Device:R R3
U 1 1 64A83DBD
P 2115 6485
F 0 "R3" V 1908 6485 50  0000 C CNN
F 1 "11k" V 1999 6485 50  0000 C CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 2045 6485 50  0001 C CNN
F 3 "~" H 2115 6485 50  0001 C CNN
F 4 "603-MFR-25FTE52-11K" H 2115 6485 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly HALF R1, etc. Range is 1k-100k. Use 1% or even better." H 2115 6485 50  0001 C CNN "Notes"
	1    2115 6485
	0    1    1    0   
$EndComp
Wire Wire Line
	1755 6065 1755 5940
Entry Wire Line
	1655 5840 1755 5940
Wire Wire Line
	1755 6485 1755 6590
$Comp
L power:GND #PWR05
U 1 1 64A79423
P 1755 6965
F 0 "#PWR05" H 1755 6715 50  0001 C CNN
F 1 "GND" H 1760 6792 50  0000 C CNN
F 2 "" H 1755 6965 50  0001 C CNN
F 3 "" H 1755 6965 50  0001 C CNN
	1    1755 6965
	-1   0    0    -1  
$EndComp
Wire Wire Line
	1755 6890 1755 6965
$Comp
L Device:R R2
U 1 1 64A63B1C
P 1755 6740
F 0 "R2" H 1825 6786 50  0000 L CNN
F 1 "22k" H 1825 6695 50  0000 L CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 1685 6740 50  0001 C CNN
F 3 "~" H 1755 6740 50  0001 C CNN
F 4 "603-MFR-25FTE52-22K" H 1755 6740 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly TWICE R3, etc. Range is 1k-100k. Use 1% or even better." H 1755 6740 50  0001 C CNN "Notes"
	1    1755 6740
	1    0    0    -1  
$EndComp
$Comp
L Device:R R4
U 1 1 64AD0594
P 2435 6215
F 0 "R4" H 2505 6261 50  0000 L CNN
F 1 "22k" H 2505 6170 50  0000 L CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 2365 6215 50  0001 C CNN
F 3 "~" H 2435 6215 50  0001 C CNN
F 4 "603-MFR-25FTE52-22K" H 2435 6215 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly TWICE R3, etc. Range is 1k-100k. Use 1% or even better." H 2435 6215 50  0001 C CNN "Notes"
	1    2435 6215
	1    0    0    -1  
$EndComp
Wire Wire Line
	2435 6365 2435 6485
Wire Wire Line
	2435 6485 2610 6485
$Comp
L Device:R R5
U 1 1 64AD05AD
P 2760 6485
F 0 "R5" V 2553 6485 50  0000 C CNN
F 1 "11k" V 2644 6485 50  0000 C CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 2690 6485 50  0001 C CNN
F 3 "~" H 2760 6485 50  0001 C CNN
F 4 "603-MFR-25FTE52-11K" H 2760 6485 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly HALF R1, etc. Range is 1k-100k. Use 1% or even better." H 2760 6485 50  0001 C CNN "Notes"
	1    2760 6485
	0    1    1    0   
$EndComp
Wire Wire Line
	2435 6065 2435 5940
Entry Wire Line
	2335 5840 2435 5940
Wire Wire Line
	2265 6485 2435 6485
Connection ~ 2435 6485
$Comp
L Device:R R6
U 1 1 64AFEA22
P 3080 6215
F 0 "R6" H 3150 6261 50  0000 L CNN
F 1 "22k" H 3150 6170 50  0000 L CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 3010 6215 50  0001 C CNN
F 3 "~" H 3080 6215 50  0001 C CNN
F 4 "603-MFR-25FTE52-22K" H 3080 6215 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly TWICE R3, etc. Range is 1k-100k. Use 1% or even better." H 3080 6215 50  0001 C CNN "Notes"
	1    3080 6215
	1    0    0    -1  
$EndComp
Wire Wire Line
	3080 6365 3080 6485
Wire Wire Line
	3080 6485 3255 6485
$Comp
L Device:R R7
U 1 1 64AFEA2A
P 3405 6485
F 0 "R7" V 3198 6485 50  0000 C CNN
F 1 "11k" V 3289 6485 50  0000 C CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 3335 6485 50  0001 C CNN
F 3 "~" H 3405 6485 50  0001 C CNN
F 4 "603-MFR-25FTE52-11K" H 3405 6485 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly HALF R1, etc. Range is 1k-100k. Use 1% or even better." H 3405 6485 50  0001 C CNN "Notes"
	1    3405 6485
	0    1    1    0   
$EndComp
Wire Wire Line
	3080 6065 3080 5940
Entry Wire Line
	2980 5840 3080 5940
Wire Wire Line
	2910 6485 3080 6485
Connection ~ 3080 6485
$Comp
L Device:R R8
U 1 1 64B0A913
P 3725 6215
F 0 "R8" H 3795 6261 50  0000 L CNN
F 1 "22k" H 3795 6170 50  0000 L CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 3655 6215 50  0001 C CNN
F 3 "~" H 3725 6215 50  0001 C CNN
F 4 "603-MFR-25FTE52-22K" H 3725 6215 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly TWICE R3, etc. Range is 1k-100k. Use 1% or even better." H 3725 6215 50  0001 C CNN "Notes"
	1    3725 6215
	1    0    0    -1  
$EndComp
Wire Wire Line
	3725 6365 3725 6485
Wire Wire Line
	3725 6485 3900 6485
$Comp
L Device:R R9
U 1 1 64B0A91B
P 4050 6485
F 0 "R9" V 3843 6485 50  0000 C CNN
F 1 "11k" V 3934 6485 50  0000 C CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 3980 6485 50  0001 C CNN
F 3 "~" H 4050 6485 50  0001 C CNN
F 4 "603-MFR-25FTE52-11K" H 4050 6485 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly HALF R1, etc. Range is 1k-100k. Use 1% or even better." H 4050 6485 50  0001 C CNN "Notes"
	1    4050 6485
	0    1    1    0   
$EndComp
Wire Wire Line
	3725 6065 3725 5940
Entry Wire Line
	3625 5840 3725 5940
Wire Wire Line
	3555 6485 3725 6485
Connection ~ 3725 6485
$Comp
L Device:R R10
U 1 1 64B16872
P 4370 6215
F 0 "R10" H 4440 6261 50  0000 L CNN
F 1 "22k" H 4440 6170 50  0000 L CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 4300 6215 50  0001 C CNN
F 3 "~" H 4370 6215 50  0001 C CNN
F 4 "603-MFR-25FTE52-22K" H 4370 6215 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly TWICE R3, etc. Range is 1k-100k. Use 1% or even better." H 4370 6215 50  0001 C CNN "Notes"
	1    4370 6215
	1    0    0    -1  
$EndComp
Wire Wire Line
	4370 6365 4370 6485
Wire Wire Line
	4370 6485 4545 6485
$Comp
L Device:R R11
U 1 1 64B1687A
P 4695 6485
F 0 "R11" V 4488 6485 50  0000 C CNN
F 1 "11k" V 4579 6485 50  0000 C CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 4625 6485 50  0001 C CNN
F 3 "~" H 4695 6485 50  0001 C CNN
F 4 "603-MFR-25FTE52-11K" H 4695 6485 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly HALF R1, etc. Range is 1k-100k. Use 1% or even better." H 4695 6485 50  0001 C CNN "Notes"
	1    4695 6485
	0    1    1    0   
$EndComp
Wire Wire Line
	4370 6065 4370 5940
Entry Wire Line
	4270 5840 4370 5940
Wire Wire Line
	4200 6485 4370 6485
Connection ~ 4370 6485
$Comp
L Device:R R12
U 1 1 64B220ED
P 5015 6215
F 0 "R12" H 5085 6261 50  0000 L CNN
F 1 "22k" H 5085 6170 50  0000 L CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 4945 6215 50  0001 C CNN
F 3 "~" H 5015 6215 50  0001 C CNN
F 4 "603-MFR-25FTE52-22K" H 5015 6215 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly TWICE R3, etc. Range is 1k-100k. Use 1% or even better." H 5015 6215 50  0001 C CNN "Notes"
	1    5015 6215
	1    0    0    -1  
$EndComp
Wire Wire Line
	5015 6365 5015 6485
Wire Wire Line
	5015 6485 5190 6485
$Comp
L Device:R R13
U 1 1 64B22527
P 5340 6485
F 0 "R13" V 5133 6485 50  0000 C CNN
F 1 "11k" V 5224 6485 50  0000 C CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 5270 6485 50  0001 C CNN
F 3 "~" H 5340 6485 50  0001 C CNN
F 4 "603-MFR-25FTE52-11K" H 5340 6485 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly HALF R1, etc. Range is 1k-100k. Use 1% or even better." H 5340 6485 50  0001 C CNN "Notes"
	1    5340 6485
	0    1    1    0   
$EndComp
Wire Wire Line
	5015 6065 5015 5940
Entry Wire Line
	4915 5840 5015 5940
Wire Wire Line
	4845 6485 5015 6485
Connection ~ 5015 6485
$Comp
L Device:R R14
U 1 1 64B22535
P 5660 6215
F 0 "R14" H 5730 6261 50  0000 L CNN
F 1 "22k" H 5730 6170 50  0000 L CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 5590 6215 50  0001 C CNN
F 3 "~" H 5660 6215 50  0001 C CNN
F 4 "603-MFR-25FTE52-22K" H 5660 6215 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly TWICE R3, etc. Range is 1k-100k. Use 1% or even better." H 5660 6215 50  0001 C CNN "Notes"
	1    5660 6215
	1    0    0    -1  
$EndComp
Wire Wire Line
	5660 6365 5660 6485
Wire Wire Line
	5660 6485 5835 6485
$Comp
L Device:R R15
U 1 1 64B22541
P 5985 6485
F 0 "R15" V 5778 6485 50  0000 C CNN
F 1 "11k" V 5869 6485 50  0000 C CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 5915 6485 50  0001 C CNN
F 3 "~" H 5985 6485 50  0001 C CNN
F 4 "603-MFR-25FTE52-11K" H 5985 6485 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly HALF R1, etc. Range is 1k-100k. Use 1% or even better." H 5985 6485 50  0001 C CNN "Notes"
	1    5985 6485
	0    1    1    0   
$EndComp
Wire Wire Line
	5660 6065 5660 5940
Entry Wire Line
	5560 5840 5660 5940
Wire Wire Line
	5490 6485 5660 6485
Connection ~ 5660 6485
$Comp
L Device:R R16
U 1 1 64B2254F
P 6305 6215
F 0 "R16" H 6375 6261 50  0000 L CNN
F 1 "22k" H 6375 6170 50  0000 L CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 6235 6215 50  0001 C CNN
F 3 "~" H 6305 6215 50  0001 C CNN
F 4 "603-MFR-25FTE52-22K" H 6305 6215 50  0001 C CNN "MouserPN"
F 5 "Exact value is not critical as long as it is exactly TWICE R3, etc. Range is 1k-100k. Use 1% or even better." H 6305 6215 50  0001 C CNN "Notes"
	1    6305 6215
	1    0    0    -1  
$EndComp
Wire Wire Line
	6305 6365 6305 6485
Wire Wire Line
	6305 6065 6305 5940
Entry Wire Line
	6205 5840 6305 5940
Wire Wire Line
	6135 6485 6305 6485
Connection ~ 6305 6485
Text Label 1755 5940 0    50   ~ 0
b0
Text Label 2435 5940 0    50   ~ 0
b1
Text Label 3080 5940 0    50   ~ 0
b2
Text Label 3725 5940 0    50   ~ 0
b3
Text Label 4370 5940 0    50   ~ 0
b4
Text Label 5015 5940 0    50   ~ 0
b5
Text Label 5660 5940 0    50   ~ 0
b6
Text Label 6305 5940 0    50   ~ 0
b7
$Comp
L Device:C C4
U 1 1 64B44D19
P 7305 6485
F 0 "C4" V 7053 6485 50  0000 C CNN
F 1 "100n" V 7144 6485 50  0000 C CNN
F 2 "Capacitor_THT:C_Disc_D7.0mm_W2.5mm_P5.00mm" H 7343 6335 50  0001 C CNN
F 3 "~" H 7305 6485 50  0001 C CNN
F 4 "810-FG28X7R1H104KNT0" H 7305 6485 50  0001 C CNN "MouserPN"
	1    7305 6485
	0    1    1    0   
$EndComp
$Comp
L Device:C C3
U 1 1 64B457A8
P 6305 6745
F 0 "C3" H 6190 6699 50  0000 R CNN
F 1 "1.8n" H 6190 6790 50  0000 R CNN
F 2 "Capacitor_THT:C_Disc_D7.0mm_W2.5mm_P5.00mm" H 6343 6595 50  0001 C CNN
F 3 "~" H 6305 6745 50  0001 C CNN
F 4 "810-FG28X7R1H103KNT6" H 6305 6745 50  0001 C CNN "MouserPN"
F 5 "DAC output low-pass filter, goes to taste in the  470pF-10nF range" H 6305 6745 50  0001 C CNN "Notes"
	1    6305 6745
	-1   0    0    1   
$EndComp
Wire Wire Line
	6305 6595 6305 6485
$Comp
L power:GND #PWR011
U 1 1 64B55503
P 6305 6970
F 0 "#PWR011" H 6305 6720 50  0001 C CNN
F 1 "GND" H 6310 6797 50  0000 C CNN
F 2 "" H 6305 6970 50  0001 C CNN
F 3 "" H 6305 6970 50  0001 C CNN
	1    6305 6970
	-1   0    0    -1  
$EndComp
Wire Wire Line
	6305 6895 6305 6970
Wire Wire Line
	7455 6485 8080 6485
Text Label 8080 6485 2    50   ~ 0
analog_audio
$Comp
L Device:C C7
U 1 1 64B83085
P 2800 10080
F 0 "C7" H 2915 10126 50  0000 L CNN
F 1 "100n" H 2915 10035 50  0000 L CNN
F 2 "Capacitor_THT:C_Disc_D7.0mm_W2.5mm_P5.00mm" H 2838 9930 50  0001 C CNN
F 3 "~" H 2800 10080 50  0001 C CNN
F 4 "810-FG28X7R1H104KNT0" H 2800 10080 50  0001 C CNN "MouserPN"
	1    2800 10080
	1    0    0    -1  
$EndComp
Wire Wire Line
	2350 10395 2570 10395
Wire Wire Line
	2350 10230 2350 10395
Wire Wire Line
	2350 9930 2350 9730
$Comp
L Device:CP1 C6
U 1 1 64C59A52
P 2350 10080
F 0 "C6" H 2235 10126 50  0000 R CNN
F 1 "100u" H 2235 10035 50  0000 R CNN
F 2 "Capacitor_THT:CP_Radial_D6.3mm_P2.50mm" H 2350 10080 50  0001 C CNN
F 3 "~" H 2350 10080 50  0001 C CNN
F 4 "710-860020573008" H 2350 10080 50  0001 C CNN "MouserPN"
	1    2350 10080
	1    0    0    -1  
$EndComp
$Comp
L power:+5V #PWR06
U 1 1 64C67871
P 2570 9605
F 0 "#PWR06" H 2570 9455 50  0001 C CNN
F 1 "+5V" H 2585 9778 50  0000 C CNN
F 2 "" H 2570 9605 50  0001 C CNN
F 3 "" H 2570 9605 50  0001 C CNN
	1    2570 9605
	1    0    0    -1  
$EndComp
$Comp
L power:GND #PWR07
U 1 1 64C75E0C
P 2570 10535
F 0 "#PWR07" H 2570 10285 50  0001 C CNN
F 1 "GND" H 2575 10362 50  0000 C CNN
F 2 "" H 2570 10535 50  0001 C CNN
F 3 "" H 2570 10535 50  0001 C CNN
	1    2570 10535
	-1   0    0    -1  
$EndComp
Wire Wire Line
	2570 10395 2570 10535
Wire Wire Line
	2800 10230 2800 10395
Wire Wire Line
	2570 9605 2570 9730
Wire Wire Line
	2800 9730 2800 9930
Wire Wire Line
	2350 9730 2570 9730
$Comp
L 74xx:74LS273 U2
U 1 1 64F542B4
P 14050 2250
F 0 "U2" H 14275 2900 50  0000 C CNN
F 1 "74LS273" H 14280 1590 50  0000 C CNN
F 2 "Package_DIP:DIP-20_W7.62mm_Socket_LongPads" H 14050 2250 50  0001 C CNN
F 3 "http://www.ti.com/lit/gpn/sn74LS273" H 14050 2250 50  0001 C CNN
F 4 "595-SN74HCT273N" H 14050 2250 50  0001 C CNN "MouserPN"
	1    14050 2250
	1    0    0    -1  
$EndComp
Wire Wire Line
	14050 3050 14050 3145
Wire Wire Line
	14050 1450 14050 1295
Wire Wire Line
	14550 2250 14840 2250
Wire Wire Line
	14550 2350 14840 2350
Wire Wire Line
	14550 2450 14840 2450
Wire Wire Line
	14550 2150 14840 2150
Wire Wire Line
	14550 2050 14840 2050
Wire Wire Line
	14550 1950 14840 1950
Wire Wire Line
	14550 1850 14840 1850
Wire Wire Line
	14550 1750 14840 1750
Text Label 14840 1750 2    50   ~ 0
b0
Text Label 14840 1850 2    50   ~ 0
b1
Text Label 14840 1950 2    50   ~ 0
b2
Text Label 14840 2050 2    50   ~ 0
b3
Text Label 14840 2150 2    50   ~ 0
b4
Text Label 14840 2250 2    50   ~ 0
b5
Text Label 14840 2350 2    50   ~ 0
b6
Text Label 14840 2450 2    50   ~ 0
b7
Text Label 1060 5840 0    50   ~ 0
digital_audio
Text Notes 3380 5495 0    50   ~ 0
DIGITAL-TO-ANALOG\nLADDER/R2R CONVERTER\n(COVOX MAGIC!)
Text Label 13085 2750 0    50   ~ 0
latch_clear
Text Notes 7570 7515 0    50   ~ 0
AUDIO IS CONNECTED TO AMPLIFIER,\nUNLESS A JACK IS INSERTED
NoConn ~ 8195 6585
$Comp
L Connector:AudioJack3_SwitchTR CN2
U 1 1 6525CFF2
P 8395 6685
F 0 "CN2" H 8115 6518 50  0000 R CNN
F 1 "RAW_OUT" H 8115 6609 50  0000 R CNN
F 2 "ReVox:AudioJack_SJ1-3525N" H 8395 6685 50  0001 C CNN
F 3 "~" H 8395 6685 50  0001 C CNN
F 4 "490-SJ1-3525N" H 8395 6685 50  0001 C CNN "MouserPN"
F 5 "AUDIO_OUT" H 8395 6685 50  0001 C CNN "Value"
	1    8395 6685
	-1   0    0    1   
$EndComp
Wire Wire Line
	8195 6385 8080 6385
Wire Wire Line
	8080 6485 8195 6485
Wire Wire Line
	8080 6685 8080 6485
Wire Wire Line
	8195 6685 8080 6685
Wire Wire Line
	8080 6785 8080 7070
Wire Wire Line
	8195 6785 8080 6785
Connection ~ 8080 6485
Text Label 11465 2285 2    50   ~ 0
latch_clk
Wire Wire Line
	10965 2085 11465 2085
Wire Wire Line
	1890 3875 1510 3875
Text Label 1510 3875 0    50   ~ 0
ext_audio
Wire Wire Line
	10965 1785 11465 1785
Entry Wire Line
	11465 1985 11565 2085
Entry Wire Line
	11465 2085 11565 2185
Entry Wire Line
	11465 2185 11565 2285
Entry Wire Line
	11465 1785 11565 1885
Wire Bus Line
	11565 3425 9365 3425
$Comp
L power:GND #PWR016
U 1 1 6534BA03
P 8080 7070
F 0 "#PWR016" H 8080 6820 50  0001 C CNN
F 1 "GND" H 8085 6897 50  0000 C CNN
F 2 "" H 8080 7070 50  0001 C CNN
F 3 "" H 8080 7070 50  0001 C CNN
	1    8080 7070
	-1   0    0    -1  
$EndComp
Connection ~ 2570 9730
Wire Wire Line
	2570 9730 2800 9730
Connection ~ 2570 10395
Wire Wire Line
	2570 10395 2800 10395
$Comp
L Device:C C2
U 1 1 65466C54
P 1605 10080
F 0 "C2" H 1720 10126 50  0000 L CNN
F 1 "100n" H 1720 10035 50  0000 L CNN
F 2 "Capacitor_THT:C_Disc_D7.0mm_W2.5mm_P5.00mm" H 1643 9930 50  0001 C CNN
F 3 "~" H 1605 10080 50  0001 C CNN
F 4 "810-FG28X7R1H104KNT0" H 1605 10080 50  0001 C CNN "MouserPN"
	1    1605 10080
	1    0    0    -1  
$EndComp
$Comp
L power:+5V #PWR03
U 1 1 654671B7
P 1605 9805
F 0 "#PWR03" H 1605 9655 50  0001 C CNN
F 1 "+5V" H 1620 9978 50  0000 C CNN
F 2 "" H 1605 9805 50  0001 C CNN
F 3 "" H 1605 9805 50  0001 C CNN
	1    1605 9805
	1    0    0    -1  
$EndComp
$Comp
L power:GND #PWR04
U 1 1 654671C1
P 1605 10355
F 0 "#PWR04" H 1605 10105 50  0001 C CNN
F 1 "GND" H 1610 10182 50  0000 C CNN
F 2 "" H 1605 10355 50  0001 C CNN
F 3 "" H 1605 10355 50  0001 C CNN
	1    1605 10355
	-1   0    0    -1  
$EndComp
Wire Wire Line
	1605 10230 1605 10355
Wire Wire Line
	1605 9805 1605 9930
$Comp
L C16-Exp-Port:C16-Exp-Port CN1
U 1 1 64651B19
P 2640 2875
F 0 "CN1" H 2640 4440 50  0000 C CNN
F 1 "EXPANSION_PORT" H 2640 4349 50  0000 C CNN
F 2 "ReVox:C16_Cart_Conn" H 2640 1225 50  0001 C CNN
F 3 "DOCUMENTATION" H 2640 1125 50  0001 C CNN
F 4 "-" H 2640 2875 50  0001 C CNN "MouserPN"
	1    2640 2875
	1    0    0    -1  
$EndComp
Wire Wire Line
	1080 9800 1080 9925
Wire Wire Line
	1080 10225 1080 10350
$Comp
L power:GND #PWR02
U 1 1 654CD058
P 1080 10350
F 0 "#PWR02" H 1080 10100 50  0001 C CNN
F 1 "GND" H 1085 10177 50  0000 C CNN
F 2 "" H 1080 10350 50  0001 C CNN
F 3 "" H 1080 10350 50  0001 C CNN
	1    1080 10350
	-1   0    0    -1  
$EndComp
$Comp
L power:+5V #PWR01
U 1 1 654CD04E
P 1080 9800
F 0 "#PWR01" H 1080 9650 50  0001 C CNN
F 1 "+5V" H 1095 9973 50  0000 C CNN
F 2 "" H 1080 9800 50  0001 C CNN
F 3 "" H 1080 9800 50  0001 C CNN
	1    1080 9800
	1    0    0    -1  
$EndComp
$Comp
L Device:C C1
U 1 1 654CCAF8
P 1080 10075
F 0 "C1" H 1195 10121 50  0000 L CNN
F 1 "100n" H 1195 10030 50  0000 L CNN
F 2 "Capacitor_THT:C_Disc_D7.0mm_W2.5mm_P5.00mm" H 1118 9925 50  0001 C CNN
F 3 "~" H 1080 10075 50  0001 C CNN
F 4 "810-FG28X7R1H104KNT0" H 1080 10075 50  0001 C CNN "MouserPN"
	1    1080 10075
	1    0    0    -1  
$EndComp
Text Label 11465 2085 2    50   ~ 0
a3
Text Label 11465 1785 2    50   ~ 0
a9
Text Label 11465 1685 2    50   ~ 0
r_~w
Text Label 11465 1585 2    50   ~ 0
latch_clear
Entry Wire Line
	11465 1885 11565 1985
NoConn ~ 1890 3775
NoConn ~ 1890 1975
NoConn ~ 1890 2175
NoConn ~ 1890 2275
NoConn ~ 1890 2375
NoConn ~ 1890 2475
NoConn ~ 1890 2575
NoConn ~ 1890 2675
NoConn ~ 1890 2775
NoConn ~ 1890 2875
NoConn ~ 3390 1775
NoConn ~ 3390 1975
NoConn ~ 3390 2075
$Comp
L Amplifier_Operational:TLC272 U?
U 1 1 65C5C5F8
P 12660 6200
AR Path="/65BF4077/65C5C5F8" Ref="U?"  Part="1" 
AR Path="/65C5C5F8" Ref="U3"  Part="1" 
F 0 "U3" H 12660 5833 50  0000 C CNN
F 1 "TLC272" H 12660 5924 50  0000 C CNN
F 2 "Package_DIP:DIP-8_W7.62mm_Socket_LongPads" H 12660 6200 50  0001 C CNN
F 3 "http://www.ti.com/lit/ds/symlink/tlc272.pdf" H 12660 6200 50  0001 C CNN
F 4 "595-TLC272BIP" H 12660 6200 50  0001 C CNN "MouserPN"
	1    12660 6200
	1    0    0    1   
$EndComp
$Comp
L Amplifier_Operational:TLC272 U?
U 2 1 65C5C5FE
P 10995 6100
AR Path="/65BF4077/65C5C5FE" Ref="U?"  Part="2" 
AR Path="/65C5C5FE" Ref="U3"  Part="2" 
F 0 "U3" H 10995 5733 50  0000 C CNN
F 1 "TLC272" H 10995 5824 50  0000 C CNN
F 2 "Package_DIP:DIP-8_W7.62mm_Socket_LongPads" H 10995 6100 50  0001 C CNN
F 3 "http://www.ti.com/lit/ds/symlink/tlc272.pdf" H 10995 6100 50  0001 C CNN
F 4 "595-TLC272BIP" H 10995 6100 50  0001 C CNN "MouserPN"
	2    10995 6100
	1    0    0    1   
$EndComp
Wire Wire Line
	11295 6100 11490 6100
Wire Wire Line
	11490 6100 11490 5670
Connection ~ 11490 6100
Wire Wire Line
	11490 6100 11740 6100
$Comp
L Device:CP1 C?
U 1 1 65C5C61C
P 13440 6200
AR Path="/6579482E/65C5C61C" Ref="C?"  Part="1" 
AR Path="/65C5C61C" Ref="C5"  Part="1" 
AR Path="/65BF4077/65C5C61C" Ref="C?"  Part="1" 
F 0 "C5" V 13692 6200 50  0000 C CNN
F 1 "1u" V 13601 6200 50  0000 C CNN
F 2 "Capacitor_THT:CP_Radial_D5.0mm_P2.00mm" H 13440 6200 50  0001 C CNN
F 3 "~" H 13440 6200 50  0001 C CNN
F 4 "710-860010672005" H 13440 6200 50  0001 C CNN "MouserPN"
	1    13440 6200
	0    -1   -1   0   
$EndComp
Wire Wire Line
	12960 6200 13075 6200
Wire Wire Line
	13075 6200 13075 5715
Wire Wire Line
	13075 5715 12805 5715
Wire Wire Line
	12165 5715 12165 6100
Connection ~ 12165 6100
Wire Wire Line
	12165 6100 12360 6100
Wire Wire Line
	12505 5715 12165 5715
Wire Wire Line
	12040 6100 12165 6100
Wire Wire Line
	13075 6200 13290 6200
Connection ~ 13075 6200
Wire Notes Line
	11705 5380 13155 5380
Wire Notes Line
	13155 5380 13155 6995
Wire Notes Line
	13155 6995 11705 6995
Wire Notes Line
	11705 6995 11705 5380
Wire Notes Line
	11675 5200 11675 6995
Text Notes 10850 6970 0    50   ~ 0
INVERTING AMPLIFIER
Text Notes 12425 6975 0    50   ~ 0
INVERTING BUFFER
Wire Wire Line
	13745 6635 13745 6720
$Comp
L power:GND #PWR?
U 1 1 65C5C64A
P 13745 6720
AR Path="/6579482E/65C5C64A" Ref="#PWR?"  Part="1" 
AR Path="/65C5C64A" Ref="#PWR0101"  Part="1" 
AR Path="/65BF4077/65C5C64A" Ref="#PWR?"  Part="1" 
F 0 "#PWR0101" H 13745 6470 50  0001 C CNN
F 1 "GND" H 13750 6547 50  0000 C CNN
F 2 "" H 13745 6720 50  0001 C CNN
F 3 "" H 13745 6720 50  0001 C CNN
	1    13745 6720
	-1   0    0    -1  
$EndComp
Wire Wire Line
	13590 6200 13745 6200
Wire Wire Line
	13745 6200 13745 6335
$Comp
L Device:R R?
U 1 1 65C5C654
P 12655 5715
AR Path="/64D8F8CD/65C5C654" Ref="R?"  Part="1" 
AR Path="/65C5C654" Ref="R22"  Part="1" 
AR Path="/65BF4077/65C5C654" Ref="R?"  Part="1" 
F 0 "R22" V 12448 5715 50  0000 C CNN
F 1 "100k" V 12539 5715 50  0000 C CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 12585 5715 50  0001 C CNN
F 3 "~" H 12655 5715 50  0001 C CNN
F 4 "603-MFR-25FTE52-11K" H 12655 5715 50  0001 C CNN "MouserPN"
F 5 "1% or better" H 12655 5715 50  0001 C CNN "Notes"
	1    12655 5715
	0    1    1    0   
$EndComp
$Comp
L Device:R R?
U 1 1 65C5C65B
P 11890 6100
AR Path="/64D8F8CD/65C5C65B" Ref="R?"  Part="1" 
AR Path="/65C5C65B" Ref="R21"  Part="1" 
AR Path="/65BF4077/65C5C65B" Ref="R?"  Part="1" 
F 0 "R21" V 12097 6100 50  0000 C CNN
F 1 "100k" V 12006 6100 50  0000 C CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 11820 6100 50  0001 C CNN
F 3 "~" H 11890 6100 50  0001 C CNN
F 4 "603-MFR-25FTE52-11K" H 11890 6100 50  0001 C CNN "MouserPN"
F 5 "1% or better" H 11890 6100 50  0001 C CNN "Notes"
	1    11890 6100
	0    -1   -1   0   
$EndComp
$Comp
L Device:R R?
U 1 1 65C5C661
P 11050 5520
AR Path="/65BF4077/65C5C661" Ref="R?"  Part="1" 
AR Path="/65C5C661" Ref="R20"  Part="1" 
F 0 "R20" V 10843 5520 50  0000 C CNN
F 1 "100k" V 10934 5520 50  0000 C CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 10980 5520 50  0001 C CNN
F 3 "~" H 11050 5520 50  0001 C CNN
F 4 "603-MFR-25FTE52-11K" H 11050 5520 50  0001 C CNN "MouserPN"
F 5 "1% or better" H 11050 5520 50  0001 C CNN "Notes"
	1    11050 5520
	0    1    1    0   
$EndComp
Wire Wire Line
	13425 4860 13920 4860
Wire Wire Line
	13425 4940 13425 4860
Text Label 13920 4860 2    50   ~ 0
ext_audio
Text Label 13745 6200 1    50   ~ 0
amplified_audio
Wire Wire Line
	13675 5090 13745 5090
$Comp
L Amplifier_Operational:TLC272 U3
U 3 1 65C86123
P 3540 10065
F 0 "U3" H 3498 10111 50  0000 L CNN
F 1 "TLC272" H 3498 10020 50  0000 L CNN
F 2 "Package_DIP:DIP-8_W7.62mm_Socket_LongPads" H 3540 10065 50  0001 C CNN
F 3 "http://www.ti.com/lit/ds/symlink/tlc272.pdf" H 3540 10065 50  0001 C CNN
F 4 "595-TLC272BIP" H 3540 10065 50  0001 C CNN "MouserPN"
	3    3540 10065
	1    0    0    -1  
$EndComp
$Comp
L power:GND #PWR0103
U 1 1 65C86129
P 3440 10505
F 0 "#PWR0103" H 3440 10255 50  0001 C CNN
F 1 "GND" H 3445 10332 50  0000 C CNN
F 2 "" H 3440 10505 50  0001 C CNN
F 3 "" H 3440 10505 50  0001 C CNN
	1    3440 10505
	-1   0    0    -1  
$EndComp
Wire Wire Line
	3440 10365 3440 10505
$Comp
L power:+5V #PWR0104
U 1 1 65C86130
P 3440 9640
F 0 "#PWR0104" H 3440 9490 50  0001 C CNN
F 1 "+5V" H 3455 9813 50  0000 C CNN
F 2 "" H 3440 9640 50  0001 C CNN
F 3 "" H 3440 9640 50  0001 C CNN
	1    3440 9640
	1    0    0    -1  
$EndComp
Wire Wire Line
	3440 9640 3440 9765
Text Notes 12145 4735 0    50   ~ 0
AUDIO OUTPUT\nAMPLIFIER
$Comp
L Device:R_POT RV1
U 1 1 64DBB0C8
P 11490 5520
F 0 "RV1" V 11375 5520 50  0000 C CNN
F 1 "500k" V 11284 5520 50  0000 C CNN
F 2 "ReVox:Pot_Bourns_3306P" H 11490 5520 50  0001 C CNN
F 3 "~" H 11490 5520 50  0001 C CNN
F 4 "652-3306P-1-504" H 11490 5520 50  0001 C CNN "MouserPN"
F 5 "" H 11490 5520 50  0001 C CNN "Notes"
	1    11490 5520
	0    -1   1    0   
$EndComp
Wire Wire Line
	11340 5520 11200 5520
$Comp
L Device:R R?
U 1 1 65D46005
P 10305 6000
AR Path="/65BF4077/65D46005" Ref="R?"  Part="1" 
AR Path="/65D46005" Ref="R19"  Part="1" 
F 0 "R19" V 10098 6000 50  0000 C CNN
F 1 "100k" V 10189 6000 50  0000 C CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 10235 6000 50  0001 C CNN
F 3 "~" H 10305 6000 50  0001 C CNN
F 4 "603-MFR-25FTE52-11K" H 10305 6000 50  0001 C CNN "MouserPN"
F 5 "1% or better" H 10305 6000 50  0001 C CNN "Notes"
	1    10305 6000
	0    1    1    0   
$EndComp
Wire Wire Line
	10610 6000 10695 6000
Connection ~ 10610 6000
Wire Wire Line
	10610 5520 10610 6000
Wire Wire Line
	10900 5520 10610 5520
Wire Wire Line
	10455 6000 10610 6000
NoConn ~ 11640 5520
Wire Notes Line
	9450 6995 9450 5195
Wire Notes Line
	11675 6995 9450 6995
Wire Notes Line
	9450 5200 11675 5200
Text Label 9545 6000 0    50   ~ 0
amplifier_in
Wire Wire Line
	10045 6000 10045 5090
Wire Wire Line
	10045 5090 13175 5090
Connection ~ 10045 6000
Wire Wire Line
	10045 6000 10155 6000
Wire Wire Line
	8080 6385 8080 6000
Wire Wire Line
	8080 6000 10045 6000
$Comp
L power:+5V #PWR?
U 1 1 65EB8ABB
P 4490 9590
AR Path="/65E4CD03/65EB8ABB" Ref="#PWR?"  Part="1" 
AR Path="/65EB8ABB" Ref="#PWR0105"  Part="1" 
F 0 "#PWR0105" H 4490 9440 50  0001 C CNN
F 1 "+5V" H 4505 9763 50  0000 C CNN
F 2 "" H 4490 9590 50  0001 C CNN
F 3 "" H 4490 9590 50  0001 C CNN
	1    4490 9590
	1    0    0    -1  
$EndComp
Wire Wire Line
	4490 9590 4490 9715
$Comp
L power:GND #PWR?
U 1 1 65EB8AC2
P 4490 10585
AR Path="/65E4CD03/65EB8AC2" Ref="#PWR?"  Part="1" 
AR Path="/65EB8AC2" Ref="#PWR0106"  Part="1" 
F 0 "#PWR0106" H 4490 10335 50  0001 C CNN
F 1 "GND" H 4495 10412 50  0000 C CNN
F 2 "" H 4490 10585 50  0001 C CNN
F 3 "" H 4490 10585 50  0001 C CNN
	1    4490 10585
	-1   0    0    -1  
$EndComp
Wire Wire Line
	4490 10445 4490 10510
$Comp
L Device:R R?
U 1 1 65EB8AC9
P 4490 9865
AR Path="/65E4CD03/65EB8AC9" Ref="R?"  Part="1" 
AR Path="/65EB8AC9" Ref="R17"  Part="1" 
F 0 "R17" H 4560 9911 50  0000 L CNN
F 1 "3.3k" H 4560 9820 50  0000 L CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 4420 9865 50  0001 C CNN
F 3 "~" H 4490 9865 50  0001 C CNN
	1    4490 9865
	1    0    0    -1  
$EndComp
$Comp
L Device:R R?
U 1 1 65EB8ACF
P 4490 10295
AR Path="/65E4CD03/65EB8ACF" Ref="R?"  Part="1" 
AR Path="/65EB8ACF" Ref="R18"  Part="1" 
F 0 "R18" H 4560 10341 50  0000 L CNN
F 1 "2.2k" H 4560 10250 50  0000 L CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 4420 10295 50  0001 C CNN
F 3 "~" H 4490 10295 50  0001 C CNN
	1    4490 10295
	1    0    0    -1  
$EndComp
Wire Wire Line
	4490 10015 4490 10075
Wire Wire Line
	4490 10075 4965 10075
Connection ~ 4490 10075
Wire Wire Line
	4490 10075 4490 10145
$Comp
L power:VCOM #PWR?
U 1 1 65EB8AD9
P 4965 9590
AR Path="/65E4CD03/65EB8AD9" Ref="#PWR?"  Part="1" 
AR Path="/65EB8AD9" Ref="#PWR0107"  Part="1" 
F 0 "#PWR0107" H 4965 9440 50  0001 C CNN
F 1 "VCOM" H 4980 9763 50  0000 C CNN
F 2 "" H 4965 9590 50  0001 C CNN
F 3 "" H 4965 9590 50  0001 C CNN
	1    4965 9590
	1    0    0    -1  
$EndComp
Wire Wire Line
	4965 9590 4965 10075
Wire Wire Line
	4965 10140 4965 10075
Connection ~ 4965 10075
Wire Wire Line
	4965 10440 4965 10510
Wire Wire Line
	4965 10510 4490 10510
Connection ~ 4490 10510
Wire Wire Line
	4490 10510 4490 10585
$Comp
L Device:CP1 C?
U 1 1 65EB8AE6
P 4965 10290
AR Path="/6579482E/65EB8AE6" Ref="C?"  Part="1" 
AR Path="/65EB8AE6" Ref="C8"  Part="1" 
AR Path="/65E4CD03/65EB8AE6" Ref="C?"  Part="1" 
F 0 "C8" H 4850 10336 50  0000 R CNN
F 1 "10u" H 4850 10245 50  0000 R CNN
F 2 "Capacitor_THT:CP_Radial_D5.0mm_P2.00mm" H 4965 10290 50  0001 C CNN
F 3 "~" H 4965 10290 50  0001 C CNN
F 4 "710-860010572002" H 4965 10290 50  0001 C CNN "MouserPN"
	1    4965 10290
	-1   0    0    -1  
$EndComp
Text Notes 4785 10825 0    50   ~ 0
LOW-PASS FILTER\n(Consider Thevenin equivalent)\nFcut = 12 Hz
$Comp
L power:VCOM #PWR?
U 1 1 65EE7807
P 12165 6240
AR Path="/65E4CD03/65EE7807" Ref="#PWR?"  Part="1" 
AR Path="/65EE7807" Ref="#PWR0108"  Part="1" 
F 0 "#PWR0108" H 12165 6090 50  0001 C CNN
F 1 "VCOM" H 12310 6310 50  0000 C CNN
F 2 "" H 12165 6240 50  0001 C CNN
F 3 "" H 12165 6240 50  0001 C CNN
	1    12165 6240
	1    0    0    -1  
$EndComp
Wire Wire Line
	12165 6240 12165 6300
Wire Wire Line
	12165 6300 12360 6300
$Comp
L power:VCOM #PWR?
U 1 1 65EF3A74
P 10500 6140
AR Path="/65E4CD03/65EF3A74" Ref="#PWR?"  Part="1" 
AR Path="/65EF3A74" Ref="#PWR0109"  Part="1" 
F 0 "#PWR0109" H 10500 5990 50  0001 C CNN
F 1 "VCOM" H 10645 6210 50  0000 C CNN
F 2 "" H 10500 6140 50  0001 C CNN
F 3 "" H 10500 6140 50  0001 C CNN
	1    10500 6140
	1    0    0    -1  
$EndComp
Wire Wire Line
	10500 6140 10500 6200
Wire Wire Line
	10500 6200 10695 6200
$Comp
L Device:R R?
U 1 1 65F0127E
P 13745 6485
AR Path="/64D8F8CD/65F0127E" Ref="R?"  Part="1" 
AR Path="/65F0127E" Ref="R23"  Part="1" 
AR Path="/65BF4077/65F0127E" Ref="R?"  Part="1" 
F 0 "R23" H 13675 6531 50  0000 R CNN
F 1 "10k" H 13675 6440 50  0000 R CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal" V 13675 6485 50  0001 C CNN
F 3 "~" H 13745 6485 50  0001 C CNN
F 4 "603-MFR-25FTE52-11K" H 13745 6485 50  0001 C CNN "MouserPN"
	1    13745 6485
	1    0    0    -1  
$EndComp
Connection ~ 13745 6200
Text Notes 6095 8085 2    50   ~ 0
LOW-PASS FILTER THAT MAKES\nTHE OUTPUT SIGNAL LESS\n"STEPPED" AND SMOOTHER.\n\nI AM UNABLE TO CALCULATE THE\nCUT FREQUENCY OF THIS, SO I JUST\nCHOSE THE VALUE "BY EAR". BUT IF\nI UNDERSTAND CORRECTLY, THE\nOUTPUT IMPEDANCE OF AN R-2R\nNETWORK IS JUST R, SO WITH R=11k\nAND C5 = 1.8n, Fcut ~~= 8 kHz.\n680p AND 820p WOULD SET IT AT\n21277 AND 17644 Hz RESPECTIVELY.\n\nYMMV, SO FEEL FREE TO TEST OTHER\nVALUES, LET'S SAY IN THE 470pF-10nF\nRANGE OR THEREABOUTS.\n\n
Wire Notes Line
	6170 6570 6610 6570
Wire Notes Line
	6610 6570 6610 7210
Wire Notes Line
	6610 7210 6170 7210
Wire Notes Line
	6170 7210 6170 6570
NoConn ~ 9965 2685
$Comp
L Jumper:Jumper_3_Open JP?
U 1 1 65C5C692
P 13425 5090
AR Path="/65BF4077/65C5C692" Ref="JP?"  Part="1" 
AR Path="/65C5C692" Ref="JP1"  Part="1" 
F 0 "JP1" H 13425 5221 50  0000 C CNN
F 1 "JMP_AUDIO_SRC" H 13425 5312 50  0000 C CNN
F 2 "Jumper:SolderJumper-3_P1.3mm_Open_RoundedPad1.0x1.5mm" H 13425 5090 50  0001 C CNN
F 3 "~" H 13425 5090 50  0001 C CNN
F 4 "-" H 13425 5090 50  0001 C CNN "MouserPN"
	1    13425 5090
	-1   0    0    1   
$EndComp
Text Notes 7760 6105 2    50   ~ 0
C6 FORMS A HIGH-PASS\nFILTER WITH R19 WHEN\nAUDIO GOES TO AMPLIFIER\n\nFcut ~~= 16 Hz
Wire Notes Line
	13215 5800 13975 5800
Wire Notes Line
	13975 5800 13975 6995
Wire Notes Line
	13975 6995 13215 6995
Wire Notes Line
	13215 6995 13215 5800
Text Notes 13225 7290 0    50   ~ 0
HIGH-PASS FILTER\n\nFcut ~~= 16 Hz
Text Notes 5125 10120 0    50   ~ 0
This is the bias voltage for the opamp.\nIt is set at +2V because the TLC272\nswings between 0 and 4V. If using a\nrail-to-rail opamp (like the LMC6482,\nfor instance), this can be set at 2.5V\nby using the same value for R17 and\nR18 (hint: 11k works fine if already\nused for the resistor ladder).
Wire Wire Line
	13745 6200 13745 5090
Wire Wire Line
	6305 6485 7155 6485
Wire Bus Line
	11565 1885 11565 3425
Wire Bus Line
	1515 3075 1515 3775
Wire Bus Line
	14940 1850 14940 2550
Wire Bus Line
	12985 1850 12985 2550
Wire Bus Line
	1055 5840 6205 5840
Wire Bus Line
	3835 2275 3835 3775
Wire Bus Line
	9365 1480 9365 3425
$EndSCHEMATC