Tuning Fork Audio Amplifier v2

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STD Tuning Fork Audio Amplifier v2

Audio

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Analog

License: GPL 3.0

Mode:

Editors' pick

Cloned from Tuning Fork Audio Amplifier

Update time： 2022-06-12 03:05:06

Creation time： 2022-03-25 04:06:21

Description

Goal: Determine most effective combination of input sensor and amplifiers.

Inputs:

Microphone
Transmissive IR sensor
Reflective IR Sensor

Outputs:

Square wave via test points
Sine wave via headphone jack

Op-amps implement 8th-order active butterworth low-pass filter with corner frequency of 440 Hz and gain of 60 dBV.

Op-amps implement 2 stage unfiltered amplifier with gain of 60 dBV.

Input is selected from 3 possible sensors with DIP switches

Headphone jack L and R channels have buffer amplifier with volume knobs. Minimum gain is less than 1. Output is AC-coupled.

Left channel signal is selected from these two options by DIP switch:

Active filter output
Unfiltered amplifier output

Right channel signal is selected form these two options by DIP switch:

Halfway through active filter
Halfway through unfiltered amplifier

Comparators produce square waves from the following signals:

sensor output
halfway through active low-pass filter
halfway through unfiltered amplifier
outut of unfiltered amplifier

Power:

5 V from micro USB
2.5 V from LDO

See attachment for block diagram and filter design report.

References:

Design Drawing

schematic diagram

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Audio Signal Chain
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Power Tree
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Comparators
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Headphones Out
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PCB

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PCB_Tuning Fork Audio Amplifier v2
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BOM

BOM download Purchase Parts

ID	Name	Designator	Footprint	Quantity	BOM_Supplier	BOM_Manufacturer Part	BOM_Manufacturer	BOM_Supplier Part	BOM_JLCPCB Part Class
1	100nF	C1,C3,C5,C8,C9,C15,C16,C34,C49,C50,C12,C13,C17,C37,C39	C0402_NEW	15	LCSC	CL05B104KO5NNNC	SAMSUNG	C1525	Basic Part
2	1uF	C2,C6,C7,C14,C18	C0805	5	LCSC	CL21B105KBFNNNE	SAMSUNG	C28323	Basic Part
3	2.2uF	C10,C31,C33,C4,C19,C40,C41,C42,C43	C1206	9	LCSC	CL31B225KBHNNNE	SAMSUNG	C50254	Basic Part
4	22uF	C11	C1210	1	LCSC	CL32B226KAJNNNE	Samsung Electro-Mechanics	C309062	Extended Part
5	ITR8307/S17/TR8(B)	K1	OPTO-SMD_ITR8307-S17-TR8-B-BL	1	LCSC	ITR8307/S17/TR8(B)	EVERLIGHT	C81632	Extended Part
6	AP3722AT	M1	MIC-SMD_4P-L3.8-W2.3-P2.66-BR	1	LCSC	AP3722AT	ALLPOWER(铨力)	C918198	Extended Part
7	270Ω	R1	R0603	1	LCSC	0603WAF2700T5E	UniOhm	C22966	Basic Part
8	820Ω	R2	R0603	1	LCSC	0603WAF8200T5E	UniOhm	C23253	Basic Part
9	1.5kΩ	R3	R0603	1	LCSC	0603WAF1501T5E	UniOhm	C22843	Basic Part
10	390Ω	R4,R19	R0603	2	LCSC	0603WAF3900T5E	UniOhm	C23151	Basic Part
11	560Ω	R5	R0603	1	LCSC	0603WAF5600T5E	UniOhm	C23204	Basic Part
12	2.2kΩ	R6	R0603	1	LCSC	0603WAF2201T5E	UniOhm	C4190	Basic Part
13	330Ω	R7,R12	R0603	2	LCSC	0603WAF3300T5E	UniOhm	C23138	Basic Part
14	0Ω	R8,R20,R21	R0603	3	LCSC	0603WAF0000T5E	UniOhm	C21189	Basic Part
15	1.8kΩ	R16	R0603	1	LCSC	0603WAF1801T5E	UniOhm	C4177	Basic Part
16	68Ω	R17,R63	R0603	2	LCSC	0603WAF680JT5E	UniOhm	C27592	Basic Part
17	150Ω	R18	R0603	1	LCSC	0603WAF1500T5E	UniOhm	C22808	Basic Part
18	33kΩ	R36,R38	R0603	2	LCSC	0603WAF3302T5E	UniOhm	C4216	Basic Part
19	1kΩ	R37,R40	R0603	2	LCSC	0603WAF1001T5E	UniOhm	C21190	Basic Part
20	3kΩ	R64,R65,R66,R9,R10,R11	R0603	6	LCSC	0603WAF3001T5E	UniOhm	C4211	Basic Part
21	120Ω	R67	R0603	1	LCSC	0603WAF1200T5E	UniOhm	C22787	Basic Part
22	680Ω	R69,R70,R71	R0603	3	LCSC	0603WAF6800T5E	UniOhm	C23228	Basic Part
23	KF1001-04P-R0-GL-DFT-01B	SW2,SW3	SW-TH_8P-L11.6-W10.0-P2.54-LS7.62	2	LCSC	KF1001-04P-R0-GL-DFT-01B	凯峰	C976326	Extended Part
24	MCP6002T-I/SN	U1,U3,U29,U45	SOIC-8_L4.9-W3.9-P1.27-LS6.0-BL	4	LCSC	MCP6002T-I/SN	MICROCHIP	C7377	Basic Part
25	5002	U5,U6,U7,U8,U9,U28,U30,U51,U52,U10,U11,U34,U35,U44,U46	TEST-TH_BD2.54-P1.39	15	LCSC	5002	Keystone	C238123	Extended Part
26	DY-ITR1100	U50	OPTO-TH_4P-L17.6-W5.8-P2.54-TL	1	LCSC	DY-ITR1100	TONYU	C841512	Extended Part
27	600Ω	L1	L0603	1	LCSC	GZ1608D601TF	Sunlord	C1002	Basic Part
28	0603White light_C2290	LED1	LED0603-R-RD_WHITE	1	LCSC	0603White light	KENTO	C2290	Basic Part
29	430Ω	R14,R15	R0603	2	LCSC	0603WAF4300T5E	UniOhm	C23170	Basic Part
30	SK12D07VG4	SW1	SW-TH_SK12D07VG4	1	LCSC	SK12D07VG4	SHOU HAN	C393937	Extended Part
31	LM317AG-TN3-R	U2	TO-252-2_L6.5-W6.1-P4.58-LS10.0-TL	1	LCSC	LM317AG-TN3-R	UTC	C75510	Basic Part
32	5001	U15,U16,U17,U18,U19,U20,U40,U41,U42,U43	TEST-TH_BD2.54-P1.39	10	LCSC	5001	Keystone	C238122	Extended Part
33	105450-0101	USBC1	USB-C-SMD_TYPE-C-USB-18	1	LCSC	105450-0101	MOLEX	C134092	Extended Part
34	10kΩ	R55,R58,R59,R61	R0603	4	LCSC	0603WAF1002T5E	UniOhm	C25804	Basic Part
35	LM393DR2G	U4,U36	SOIC-8_L5.0-W4.0-P1.27-LS6.0-BL	2	LCSC	LM393DR2G	ON	C7955	Basic Part
36	PJ313D	J1	AUDIO-TH_PJ313D	1	LCSC	PJ313D	BOOMELE	C18167	Extended Part
37	10kΩ	R13,R44	RES-SMD_RK10J11R001Y	2	LCSC	RK10J11R001Y	ALPSALPINE(阿尔卑斯阿尔派)	C470765	Extended Part