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Stage Tuner for Guitars
Fast and accurate
Although you can buy a professional stage tuner for your guitar, designing and building your own device is a lot more satisfying. At first I thought it would be fairly easy to determine the fundamental frequency of a guitar signal by using a fast Fourier transform (FFT), but in practice things turned to be a lot more difficult.
Materials
Component list
Component List
Resistors
(SMD1206)
R1,R7,R8 = 33kOhm
R2 = 22kOhm
R3,R25 = 1MOhm
R4 = 47kOhm
R5,R6 = 1.2kOhm
R9,R11,R13,R15,R17,R19,R21,R23 = 47Ohm
R10,R12,R14,R16,R18,R20,R22,R24,R47,R48,R49,R50 = 10kOhm
Capacitors
(C1–C10: SMD1206)
C1 = 330pF
C2 = 3.3nF
C3 = 30nF (e.g. Mouser 581-12061C303JAT2A)
C4 = 390nF 16V
C5 = 220pF 16V
C6 = 39nF 50V
C7,C8,C9,C10 = 100nF
C11,C12 = 1000µF 35V radial (0.2” pitch; 0.5” diam.)
C13,C14 = 10µF 35V radial (0.1” pitch, 0.2” diam.)
C15 = 2.2µF 100V radial
Semiconductors
B1 = DB101 bridge rectifier
T1–T8 = BC547
T9,T10 = BC557
IC1,IC2 = ADA4096-2 or LM833 dual opamp (SOIC-8)
IC3 = 7805
IC4 = 7905
21 pcs. LED. high-efficiency, red, 3mm (for CP05–CP50, C000, CM05–CM50)
1 pc. LED, high-efficiency, red, 5mm (for LDSH)
Miscellaneous
TM4C123GXL evaluation board
DIS1 = 7-segment-display, red, common anode, 0.56", 13 mcd@10 mA (e.g. Avago HDSP-H101)
DIS2 = 7-segment-display, red, common anode, 0.3", 10 mcd@10 mA (e.g. Avago HDSP-A101)
CON2 = 2-pin pinheader, 0.1” pitch
CON4 = 3- pin pinheader, 0.1” pitch
CON5,CON6 = 12-way PCB terminal block, 0.1”pitch
SW1 = pushbutton with make contact
2 pcs. 20-way (2x10) receptacles for evaluation board, 0.1”pitch
3 pcs. jack sockets, panel mount, 0.25” diam.
PCB artwork, # 140076, download at [1]
Resistors
(SMD1206)
R1,R7,R8 = 33kOhm
R2 = 22kOhm
R3,R25 = 1MOhm
R4 = 47kOhm
R5,R6 = 1.2kOhm
R9,R11,R13,R15,R17,R19,R21,R23 = 47Ohm
R10,R12,R14,R16,R18,R20,R22,R24,R47,R48,R49,R50 = 10kOhm
Capacitors
(C1–C10: SMD1206)
C1 = 330pF
C2 = 3.3nF
C3 = 30nF (e.g. Mouser 581-12061C303JAT2A)
C4 = 390nF 16V
C5 = 220pF 16V
C6 = 39nF 50V
C7,C8,C9,C10 = 100nF
C11,C12 = 1000µF 35V radial (0.2” pitch; 0.5” diam.)
C13,C14 = 10µF 35V radial (0.1” pitch, 0.2” diam.)
C15 = 2.2µF 100V radial
Semiconductors
B1 = DB101 bridge rectifier
T1–T8 = BC547
T9,T10 = BC557
IC1,IC2 = ADA4096-2 or LM833 dual opamp (SOIC-8)
IC3 = 7805
IC4 = 7905
21 pcs. LED. high-efficiency, red, 3mm (for CP05–CP50, C000, CM05–CM50)
1 pc. LED, high-efficiency, red, 5mm (for LDSH)
Miscellaneous
TM4C123GXL evaluation board
DIS1 = 7-segment-display, red, common anode, 0.56", 13 mcd@10 mA (e.g. Avago HDSP-H101)
DIS2 = 7-segment-display, red, common anode, 0.3", 10 mcd@10 mA (e.g. Avago HDSP-A101)
CON2 = 2-pin pinheader, 0.1” pitch
CON4 = 3- pin pinheader, 0.1” pitch
CON5,CON6 = 12-way PCB terminal block, 0.1”pitch
SW1 = pushbutton with make contact
2 pcs. 20-way (2x10) receptacles for evaluation board, 0.1”pitch
3 pcs. jack sockets, panel mount, 0.25” diam.
PCB artwork, # 140076, download at [1]
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