Audio Signal Conditioning Circuit

Worked

135 days

flux

0:00

Work completed

Routed J1/J2 through AC-coupling and RF filters into SW1, and from SW1 into U1/U4 preamp +IN pins; unused inputs tied off.
Fanned out 1.65 V bias from U5 to BIAS_NET; wired VR1 wipers into the U1 feedback loops.
Added seven 100 nF decoupling capacitors (C1–C7) to power pins of U1, U4, U2, U3, and U5, with returns to ground.

Remaining tasks

Implement master volume (VR2) and design selectable 40/80 kHz RC filters; connect to U3 inputs.
Finalize 3.3 V buffers in U3 with series resistors, D2/D3 Schottkys, U6/U7 TVS, and F1/F2 PTCs.
Prepare schematic for 2-layer PCB: annotate star ground, add routing guidelines, run ERC to clear any airwires.

Success criteria status

Nets routed with no airwires: ✅
Combo jack to mode switch to preamps: ✅
1.65 V bias and VR1 gain control: ✅
Master volume and anti-alias filters: ❌
U3 buffers with MCU protection: ❌
PCB-ready with star ground: ❌

Recommended next step Proceed to implement the master volume stage and anti-alias filter networks (Plan step 3) to complete the signal path before moving on to MCU protection and PCB layout preparation.

135 days

Inductance

100 nH

L6 P2 - SW1 6

VR2 WIPER_1 - C8 P1

J1 1 - C1 P1

VR1 WIPER_1 - U1 -IN A

J1 1 - C1 P1

U1 OUT B - VR1 CW_2

VR2 WIPER_1 - C8 P1

J1 1 - C1 P1

F2 P2 - D3 Cathode

L6 P2 - SW1 6

J1 1 - C1 P1

VR2 WIPER_1 - C8 P1

U1 OUT B - VR1 CW_2

J1 1 - C1 P1

F2 P2 - D3 Cathode

J1 1 - C1 P1

L6 P2 - SW1 6

J1 1 - C1 P1

U1 OUT A - VR1 CW_1

J1 1 - C1 P1

VR1 WIPER_2 - U1 -IN B

J1 1 - C1 P1

L6 P2 - SW1 6

VR2 WIPER_1 - C8 P1

L6 P2 - SW1 6

J1 1 - C1 P1

L5 P2 - SW1 5

L3 P2 - SW1 3

J1 1 - C1 P1

VR2 WIPER_2 - C9 P1

J1 1 - C1 P1

L3 P2 - SW1 3

Inductance

100 nH

J1 1 - C1 P1

VR2 WIPER_2 - C9 P1

J1 1 - C1 P1

Inductance

100 nH

F2 P2 - D3 Cathode

U1 OUT A - VR1 CW_1

VR2 WIPER_1 - C8 P1

J1 1 - C1 P1

U1 OUT B - VR1 CW_2

F1 P2 - D2 Cathode

J1 1 - C1 P1

VR2 WIPER_2 - C9 P1

J1 1 - C1 P1

Inductance

100 nH

VR1 WIPER_2 - U1 -IN B

L5 P2 - SW1 5

J1 1 - C1 P1

U1 OUT A - VR1 CW_1

J1 1 - C1 P1

Inductance

100 nH

J1 1 - C1 P1

VR1 WIPER_1 - U1 -IN A

J1 1 - C1 P1

Inductance

100 nH

J1 1 - C1 P1

Capacitance

100 nF

Capacitance

220 nF

C11

Capacitance

390 pF

Capacitance

820 pF

Capacitance

220 nF

Capacitance

820 pF

Capacitance

100 nF

C10

Capacitance

390 pF

Capacitance

100 nF

Capacitance

100 nF

Capacitance

100 nF

Hole1

Hole4

TP1

TP2

Hole2

Hole3

TP3

TP1

SW1

GND

VR1

VR2

Reviews

Ground
A common return path for electric current. Commonly known as ground.
jharwinbarrozo
20.5M
Net Portal
Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
jharwinbarrozo
43.0M
Power Net Portal
Wirelessly connects power nets on schematic. Identical to the net portal, but with a power symbol. Used to organize schematics and separate functional blocks. To wirelessly connect power net portals, give them the same designator. #portal #power
jharwinbarrozo
11.4M
Generic Resistor
A generic fixed resistor ideal for rapid circuit topology development. Its footprint automatically adapts based on the selected package case code—supporting 0402, 0603, 0805, 1203, and many other standard SMD packages, as well as axial horizontal and vertical configurations. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard resistor values: 1.0 ohm, 10 ohm, 100 ohm, 1.0k ohm, 10k ohm, 100k ohm, 1.0M ohm 1.1 ohm, 11 ohm, 110 ohm, 1.1k ohm, 11k ohm, 110k ohm, 1.1M ohm 1.2 ohm, 12 ohm, 120 ohm, 1.2k ohm, 12k ohm, 120k ohm, 1.2M ohm 1.3 ohm, 13 ohm, 130 ohm, 1.3k ohm, 13k ohm, 130k ohm, 1.3M ohm 1.5 ohm, 15 ohm, 150 ohm, 1.5k ohm, 15k ohm, 150k ohm, 1.5M ohm 1.6 ohm, 16 ohm, 160 ohm, 1.6k ohm, 16k ohm, 160k ohm, 1.6M ohm 1.8 ohm, 18 ohm, 180 ohm, 1.8K ohm, 18k ohm, 180k ohm, 1.8M ohm 2.0 ohm, 20 ohm, 200 ohm, 2.0k ohm, 20k ohm, 200k ohm, 2.0M ohm 2.2 ohm, 22 ohm, 220 ohm, 2.2k ohm, 22k ohm, 220k ohm, 2.2M ohm 2.4 ohm, 24 ohm, 240 ohm, 2.4k ohm, 24k ohm, 240k ohm, 2.4M ohm 2.7 ohm, 27 ohm, 270 ohm, 2.7k ohm, 27k ohm, 270k ohm, 2.7M ohm 3.0 ohm, 30 ohm, 300 ohm, 3.0K ohm, 30K ohm, 300K ohm, 3.0M ohm 3.3 ohm, 33 ohm, 330 ohm, 3.3k ohm, 33k ohm, 330k ohm, 3.3M ohm 3.6 ohm, 36 ohm, 360 ohm, 3.6k ohm, 36k ohm, 360k ohm, 3.6M ohm 3.9 ohm, 39 ohm, 390 ohm, 3.9k ohm, 39k ohm, 390k ohm, 3.9M ohm 4.3 ohm, 43 ohm, 430 ohm, 4.3k ohm, 43K ohm, 430K ohm, 4.3M ohm 4.7 ohm, 47 ohm, 470 ohm, 4.7k ohm, 47k ohm, 470k ohm, 4.7M ohm 5.1 ohm, 51 ohm, 510 ohm, 5.1k ohm, 51k ohm, 510k ohm, 5.1M ohm 5.6 ohm, 56 ohm, 560 ohm, 5.6k ohm, 56k ohm, 560k ohm, 5.6M ohm 6.2 ohm, 62 ohm, 620 ohm, 6.2k ohm, 62K ohm, 620K ohm, 6.2M ohm 6.8 ohm, 68 ohm, 680 ohm, 6.8k ohm, 68k ohm, 680k ohm, 6.8M ohm 7.5 ohm, 75 ohm, 750 ohm, 7.5k ohm, 75k ohm, 750k ohm, 7.5M ohm 8.2 ohm, 82 ohm, 820 ohm, 8.2k ohm, 82k ohm, 820k ohm, 8.2M ohm 9.1 ohm, 91 ohm, 910 ohm, 9.1k ohm, 91k ohm, 910k ohm, 9.1M ohm #generics #CommonPartsLibrary
jharwinbarrozo
1.5M
Generic Capacitor
A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF, 10pF, 100pF, 1000pF, 0.01uF, 0.1uF, 1.0uF, 10uF, 100uF, 1000uF, 10000uF 1.1pF, 11pF, 110pF, 1100pF 1.2pF, 12pF, 120pF, 1200pF 1.3pF, 13pF, 130pF, 1300pF 1.5pF, 15pF, 150pF, 1500pF, 0.015uF, 0.15uF, 1.5uF, 15uF, 150uF, 1500uF 1.6pF, 16pF, 160pF, 1600pF 1.8pF, 18pF, 180pF, 1800pF 2.0pF, 20pF, 200pF, 2000pF 2.2pF, 22pF, 220pF, 2200pF, 0.022uF, 0.22uF, 2.2uF, 22uF, 220uF, 2200uF 2.4pF, 24pF, 240pF, 2400pF 2.7pF, 27pF, 270pF, 2700pF 3.0pF, 30pF, 300pF, 3000pF 3.3pF, 33pF, 330pF, 3300pF, 0.033uF, 0.33uF, 3.3uF, 33uF, 330uF, 3300uF 3.6pF, 36pF, 360pF, 3600pF 3.9pF, 39pF, 390pF, 3900pF 4.3pF, 43pF, 430pF, 4300pF 4.7pF, 47pF, 470pF, 4700pF, 0.047uF, 0.47uF, 4.7uF, 47uF, 470uF, 4700uF 5.1pF, 51pF, 510pF, 5100pF 5.6pF, 56pF, 560pF, 5600pF 6.2pF, 62pF, 620pF, 6200pF 6.8pF, 68pF, 680pF, 6800pF, 0.068uF, 0.68uF, 6.8uF, 68uF, 680uF, 6800uF 7.5pF, 75pF, 750pF, 7500pF 8.2pF, 82pF, 820pF, 8200pF 9.1pF, 91pF, 910pF, 9100pF #generics #CommonPartsLibrary
jharwinbarrozo
1.5M
Generic Inductor
A generic fixed inductor suitable for rapid circuit topology development. The footprint automatically adapts based on the selected package, supporting standard SMD sizes (e.g., 0402, 0603, 0805) as well as well-known inductor packages such as SDR1806, PA4320, SRN6028, and SRR1260. Standard inductor values: 1.0 nH, 10 nH, 100 nH, 1.0 µH, 10 µH, 100 µH, 1.0 mH 1.2 nH, 12 nH, 120 nH, 1.2 µH, 12 µH, 120 µH, 1.2 mH 1.5 nH, 15 nH, 150 nH, 1.5 µH, 15 µH, 150 µH, 1.5 mH 1.8 nH, 18 nH, 180 nH, 1.8 µH, 18 µH, 180 µH, 1.8 mH 2.2 nH, 22 nH, 220 nH, 2.2 µH, 22 µH, 220 µH, 2.2 mH 2.7 nH, 27 nH, 270 nH, 2.7 µH, 27 µH, 270 µH, 2.7 mH 3.3 nH, 33 nH, 330 nH, 3.3 µH, 33 µH, 330 µH, 3.3 mH 3.9 nH, 39 nH, 390 nH, 3.9 µH, 39 µH, 390 µH, 3.9 mH 4.7 nH, 47 nH, 470 nH, 4.7 µH, 47 µH, 470 µH, 4.7 mH 5.6 nH, 56 nH, 560 nH, 5.6 µH, 56 µH, 560 µH, 5.6 mH 6.8 nH, 68 nH, 680 nH, 6.8 µH, 68 µH, 680 µH, 6.8 mH 8.2 nH, 82 nH, 820 nH, 8.2 µH, 82 µH, 820 µH, 8.2 mH #generics #CommonPartsLibrary
jharwinbarrozo
15.8k
Terminal
An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.
natarius
RMCF0805JT47K0
47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film #forLedBlink
jharwinbarrozo
1.2M
875105359001
10uF Capacitor Aluminum Polymer 20% 16V SMD 5x5.3mm #forLedBlink #commonpartslibrary #capacitor #aluminumpolymer #radialcan
jharwinbarrozo
1.2M
CTL1206FYW1T
Yellow 595nm LED Indication - Discrete 1.7V 1206 (3216 Metric) #forLedBlink
jharwinbarrozo
1.1M

Project Name

Description

Stereo Balanced Audio Front-End for Daisy Seed 2 DFM Platform

Properties

System Architecture

Diagram

Layout Guidance

Pricing & Availability

Distributor	Qty 1
Arrow	$12.84–$18.47
Digi-Key	$9.20–$10.78
LCSC	$35.66–$35.90
Mouser	$46.39–$46.51
TME	$14.52
Verical	$28.03–$44.42

Controls

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