# Mono Audio Amplifier ## Description Compact 5 V-12 V mono audio amplifier with stereo 3.5 mm summed input, 10 kOhm log volume control, LM386 power stage, speaker output, power LED, and 2-layer 50 mm x 50 mm layout target. ## Project Details - **Owner:** mixikid - **Created:** 4/5/2026 - **Last Updated:** 4/13/2026 - **Visibility:** Public ## Key Components ### J1 — [AUDIO JACK 3.5mm](https://www.flux.ai/adrian95/audio-jack-35mm.md) - Package: Through Hole - Manufacturer Part Number: a - Role Details: 3.5mm stereo TRS jack for left, right, and ground line-level input - Role: Audio Input - Implementation Details: Unswitched contacts only; switch pins intentionally left unconnected - Part Type: Connector **Pins:** - ~ - ~ - GND - L - R ### J2 — [PJ-037A](https://www.flux.ai/vasy_skral/pj-037a.md) - Role: Power Input - Manufacturer Name: CUI Devices - Part Type: Connector - Datasheet URL: https://www.cuidevices.com/product/resource/pj-037a.pdf - Manufacturer Part Number: PJ-037A - Role Details: 5.5mm x 2.1mm center-positive barrel jack for 5V-12V DC input - Package: Through Hole **Pins:** - Center pin [pin 1] - Terminal [pin 2] ### LED1 — [LED THT D5.0mm](https://www.flux.ai/jharwinbarrozo/led-tht-d5p0mm.md) - Manufacturer Part Number: a - Part Type: LED - Role Details: Shows DC input power is present - Forward Voltage: 1.7V - Package: Through Hole - Role: Power Indicator **Pins:** - A [pin 2] - K [pin 1] ### RV1 — [PTA2043-2010CIB103](https://www.flux.ai/jecstronic/pta2043-2010cib103.md) - Manufacturer Name: Bourns Inc. - Datasheet URL: https://www.bourns.com/docs/Product-Datasheets/pta.pdf - Resistance: 10kΩ - Part Type: Potentiometer - Manufacturer Part Number: PTA2043-2010CIB103 - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - CCW [pin 1] - CW [pin 3] - WIPER [pin 2] ### U1 — [LM386N-4/NOPB](https://www.flux.ai/adrian95/lm386n-4nopb.md) - License: https://creativecommons.org/licenses/by/4.0/ - Role: Amplifier - Manufacturer Name: Texas Instruments - Package: PDIP-8 - Implementation Details: Pins GAIN_1 and GAIN_2 intentionally left open for default LM386 gain configuration - Datasheet URL: https://www.ti.com/general/docs/suppproductinfo.tsp?distId=10&gotoUrl=http%253A%252F%252Fwww.ti.com%252Flit%252Fgpn%252Flm386 - Part Type: Integrated Circuit - Role Details: Single-supply Class-AB mono speaker amplifier for 5V-12V operation - Manufacturer Part Number: LM386N-4/NOPB **Pins:** - -_INPUT [pin 2] - +_INPUT [pin 3] - BYPASS [pin 7] - GAIN_1 [pin 1] - GAIN_2 [pin 8] - GND [pin 4] - VOUT [pin 5] - VS [pin 6] ### U2 — [KF128-5.08-2P-AA](https://www.flux.ai/lcsc/kf128-5p08-2p-aa.md) - Operating Temperature: -40℃~+105℃ - Current Rating: 24A - JLCPCB Part Class: Extended Part - Manufacturer Name: KEFA(科发) - Connector Rows: 1 - Package or Case Code: CONN-TH_P5.08_KF128-5.08-2P - Part Type: Screw terminal - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2408211511_Cixi-Kefa-Elec-KF128-5-08-2P-AA_C474952.pdf - Connector Pitch: 5.08mm - Connector Type: Screw terminal - Connector Positions: 2 - LCSC Part Number: C474952 - Role Details: 2-pin screw terminal for 4Ohm or 8Ohm speaker connection - Connector Gender: Female - Manufacturer Part Number: KF128-5.08-2P-AA - Role: Speaker Output - Package: Through Hole - Product Info Url: https://lcsc.com/product-detail/New-Quadratic-Unclassified-Data_Cixi-Kefa-Elec-KF128-5-08-2P_C474952.html **Pins:** - 1 [pin 1] - 2 [pin 2] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/mixikid/mono-audio-amplifier](https://www.flux.ai/mixikid/mono-audio-amplifier).* --- *Generated from [https://www.flux.ai/mixikid/mono-audio-amplifier](https://www.flux.ai/mixikid/mono-audio-amplifier)*