k 1k 100k 0.22uF In Out 50k R3R4 R1 R2 R5* C1 U1 OPA V+ V- CMoy standard [Rainer Boettchers, 2003, v = R3 + R4 R3 = R4 R3 1 + *) R5 opt., Ohm Cmoy headphone amplifier (© Chu Moy, OPA132-pin compatible: LM741 (lower Vcc, lower P0) OPA2132-pin compatible: TL072C, NE5532 (higher Out-Z) R in = R2

k 1k 100k 0.22uF In Out 50k R3R4 R1 R2 R5 C1 U1 OPA V+ V- CMoy 47 design [Rainer Boettchers, 2003, U2 OPA V+ V Cmoy47 headphone amplifier (© Chu Moy/Apheared,

M In Out R2 R5 U1 OPA V+ V- Simple impedance follower pin-compatible opamp:TL072C (lower quiescent current) Impedance follower [Rainer Boettchers, 2003,

k 1k 100k 0.22uF LineInR Out 100k R3R4 R1 R2 R5* C1 U1/1 OPA V+ V- 100k k 1k 100k 0.22uF LineInL Out 100k R3R4 R1 R2 R5* C1 U1/2 OPA V+ V- 100k k 1k 4.7k 1k TL072C U2/1 7 4 V+ V- 10k 7 4 V+ V- U2/2 0.22uF InstrIn 1M Practice amp w/ LineIn & Instr (var. Line-In) R6 R7 0.47uF R8 1M

k 1k 100k 0.22uF LineInR Out R3R4 R2 R5* C1 U1/1 OPA V+ V- 47k k 1k 100k 0.22uF LineInL Out R3R4 R2 R5* C1 U1/2 OPA V+ V- 47k k 2.2k 1k 4.7k 1k TL072C U2/1 7 4 V+ V- 10k 7 4 V+ V- U2/2 0.22uF InstrIn 1M Practice amp w/ LineIn & Instr (const. Line-In) R6 R7 0.47uF R8 1M

Battery common rail supply 470uF 4.7k + 470uF + 4.7k 3.3k +9V -9V 2 x 9V LED

k470k 10k 0.47u In Out R3R4 R2 R5* C1 U1 OPA V+ V- g = R4 R3 *) R5 opt., Ohm 10k Single supply operation [Rainer Boettchers, 2003, Single supply operation for buffer amp R in = R3 100u + 220p 0.22u +

Musical EQ

OpAmp audio projects Date:14 April :26 Page:9 0 0 Out A Out B In A In B Vcc+ Vcc - Gnd 27 10k 0.22u 4.7u 100k 1k OPA2132 [Rainer Boettchers, 2003, 4.7u u B80C1500 ~ ~ ~ ~ 15V~ CMoy standard, power supply version

OpAmp audio projects Date:14 April :26 Page: Out A Out B In A In B Vcc+ Vcc - Gnd 47 1M OPA2132 [Rainer Boettchers, 2003, 47u ++ Pickup follower 10k

OpAmp audio projects Date:14 April :26 Page: Out A Out B In A In B Vcc+ Vcc - Gnd 27 10k 0.22u 4.7u 100k 1k OPA2132 [Rainer Boettchers, 2003, 4.7u u B80C1500 ~ ~ ~ ~ 15V~ OPA CMoy 47, power supply version

OpAmp audio projects Date:14 April :26 Page: Out A Out B In A In B Vcc+ Vcc - Gnd 27 10k 0.22u 220k 1k OPA2132 [Rainer Boettchers, 2003, 470u + + OPA k V+V- CMoy 47, battery version

OpAmp audio projects Date:14 April :26 Page: [Rainer Boettchers, 2003, CMoy standard, battery version Components side viewPrint side view

OpAmp audio projects Date:14 April :26 Page: [Rainer Boettchers, 2003, CMoy standard, battery version (alternate layout)

OpAmp audio projects Date:14 April :26 Page: [Rainer Boettchers, 2003, CMoy booster, low power battery version R3gain 4.7k k k2.0 Components side viewPrint side view

OpAmp audio projects Date:14 April :26 Page: In N Vcc+ TL072 [Rainer Boettchers, 2003, Single supply pickup booster 10k + 10u k 470k 10k 0.47u 10k k 0.47u 470k In B 10k Gnd 10u In N Vcc+ TL072 10k + 10u k 470k 10k 0.47u 10k k 0.47u 470k In B 10k Gnd 10u Components side viewPrint side view

OpAmp audio projects Date:14 April :26 Page: [Rainer Boettchers, 2003, CMoy practice amp, battery version, const. LineIn Out A Out B In A In B Vcc+Vcc - Gnd 27 10k 0.22u 4.7k 47k 100k1k OPA k 470u/25V + + Main stage Preamp stage Instr 0.22u 1M TL072C Gnd 1k 4.7k 1k 2.2k Pre out Vcc+ Vcc - Instr. vol. Gnd Put feedback resistors on solder pins to adapt gain to instrument output level Comments: May be k pots; if > 100k put 10k across 100k Pre In 47k 100k 0.47u 1M

OpAmp audio projects Date:14 April :26 Page: Out A Out B In A In B Vcc+ Vcc - Gnd 27 10k 0.22u 4.7k 100k 1k OPA k 470u + + [Rainer Boettchers, 2003, CMoy standard, battery version, single board Input Headphone Volume

OpAmp audio projects Date:14 April :26 Page: Out A Out BIn A In B Vcc+ Vcc - Gnd 27 10k 0.22u 4.7k 100k OPA2132 [Rainer Boettchers, 2003, 4.7k 470u + + CMoy standard, switchable gain, battery version 4701k2.2k4.7k4701k2.2k4.7k 1: g = 22 2: g = 11 3: g = 6 4: g = 3 and more 1414

OpAmp audio projects Date:14 April :26 Page: [Rainer Boettchers, 2003, Equalizer EQ3 In Vcc- 1u Gnd Components side view TL072 Vcc+ Out 220k 1u 1.8k 3.6k 11k 500k 1.8k 5n 3.6k 5n 22n 50n 11k 100k