# Modular High-End Audio Preamp ## Description Modular high-end stereo preamp with selectable analog/DSP tone control, MUSES72320 volume control, MCU interface, and linear power rails. ## Project Details - **Owner:** pjwjanssen - **Created:** 7/1/2026 - **Last Updated:** 7/5/2026 - **Visibility:** Public - **Implementation Details:** Modular stereo preamp: OPA2134 buffers, NJW/ADAU tone module select, MUSES72320 volume, MCU control - **Domain:** Audio - **Operating Voltage:** 15V - **Human Interface:** Encoder - **Connectivity:** I2C - **Stars:** 1 ## Key Components ### J1 — [RCA Vertical - RCJ-024](https://www.flux.ai/404src/rca-vertical-rcj-024~9u.md) - Part Type: Connector - Purchase Url: https://www.mouser.com/ProductDetail/CUI-Devices/RCJ-024?qs=WyjlAZoYn510/RpqUQhCng%3D%3D - Manufacturer Part Number: 490-RCJ-024 - Role: Left input - Datasheet URL: https://www.mouser.com/datasheet/2/670/rcj_02-3159322.pdf - Manufacturer Name: CUI Devices **Pins:** - GND [pin 2] - GND [pin 2] - In [pin 1] ### J2 — [RCA Vertical - RCJ-024](https://www.flux.ai/404src/rca-vertical-rcj-024~9u.md) - Role: Right input - Part Type: Connector - Manufacturer Part Number: 490-RCJ-024 - Purchase Url: https://www.mouser.com/ProductDetail/CUI-Devices/RCJ-024?qs=WyjlAZoYn510/RpqUQhCng%3D%3D - Datasheet URL: https://www.mouser.com/datasheet/2/670/rcj_02-3159322.pdf - Manufacturer Name: CUI Devices **Pins:** - GND [pin 2] - GND [pin 2] - In [pin 1] ### J3 — [RCA Vertical - RCJ-024](https://www.flux.ai/404src/rca-vertical-rcj-024~9u.md) - Role: Left output - Part Type: Connector - Manufacturer Name: CUI Devices - Datasheet URL: https://www.mouser.com/datasheet/2/670/rcj_02-3159322.pdf - Purchase Url: https://www.mouser.com/ProductDetail/CUI-Devices/RCJ-024?qs=WyjlAZoYn510/RpqUQhCng%3D%3D - Manufacturer Part Number: 490-RCJ-024 **Pins:** - GND [pin 2] - GND [pin 2] - In [pin 1] ### J4 — [RCA Vertical - RCJ-024](https://www.flux.ai/404src/rca-vertical-rcj-024~9u.md) - Manufacturer Name: CUI Devices - Datasheet URL: https://www.mouser.com/datasheet/2/670/rcj_02-3159322.pdf - Purchase Url: https://www.mouser.com/ProductDetail/CUI-Devices/RCJ-024?qs=WyjlAZoYn510/RpqUQhCng%3D%3D - Manufacturer Part Number: 490-RCJ-024 - Part Type: Connector - Role: Right output **Pins:** - GND [pin 2] - GND [pin 2] - In [pin 1] ### Q1 — [BC857A](https://www.flux.ai/lcsc/bc857a~f9m4.md) - Manufacturer Part Number: BC857A - LCSC Part Number: C2919766 - JLCPCB Part Class: Extended Part - Role Details: ADAU1701 VDRIVE external pass transistor for DVDD 1.8 V rail - Role: Power Conversion - Part Type: Bipolar Transistors - BJT - Package or Case Code: SOT-23-3_L2.9-W1.4-P1.90-LS2.6-BR - Manufacturer Name: CBI(创基) **Pins:** - B [pin 1] - C [pin 3] - E [pin 2] ### U1 — [OPA2134UA](https://www.flux.ai/jecstronic/opa2134ua~q8s.md) - Part Type: Operational Amplifier (OP-AMP) - Manufacturer Part Number: OPA2134UA - Datasheet URL: https://www.ti.com/general/docs/suppproductinfo.tsp?distId=10&gotoUrl=https%3A%2F%2Fwww.ti.com%2Flit%2Fgpn%2Fopa134 - Role: Input buffer - Manufacturer Name: Texas Instruments **Pins:** - -IN A [pin 2] - -IN B [pin 6] - +IN A [pin 3] - +IN B [pin 5] - OUT A [pin 1] - OUT B [pin 7] - V- [pin 4] - V+ [pin 8] ### U2 — [ADAU1701JSTZ](https://www.flux.ai/lcsc/adau1701jstz~xl0b.md) - Manufacturer Name: ADI(亚德诺) - LCSC Part Number: C3001875 - JLCPCB Part Class: Extended Part - Package or Case Code: LQFP-48_L7.0-W7.0-P0.50-LS9.0-TL - Part Type: Audio Interface ICs - Datasheet URL: https://www.analog.com/media/en/technical-documentation/data-sheets/ADAU1701.pdf - Manufacturer Part Number: ADAU1701JSTZ - Role: DSP tone module **Pins:** - ~{RESET} [pin 5] - ADC_RES [pin 3] - ADC0 [pin 2] - ADC1 [pin 4] - ADDR0 [pin 7] - ADDR1/CDATA/WB [pin 20] - AGND [pin 37] - AGND [pin 1] - AGND [pin 42] - AVDD [pin 36] - AVDD [pin 48] - CLATCH/WP [pin 21] - CM [pin 40] - DGND [pin 12] - DGND [pin 25] - DVDD [pin 13] - DVDD [pin 24] - FILTA [pin 47] - FILTD [pin 41] - IOVDD [pin 18] - MCLKI [pin 32] - MP0 [pin 11] - MP1 [pin 10] - MP10 [pin 16] - MP11 [pin 19] - MP2 [pin 29] - MP3 [pin 28] - MP4 [pin 8] - MP5 [pin 9] - MP6 [pin 15] - MP7 [pin 14] - MP8 [pin 27] - MP9 [pin 26] - OSCO [pin 31] - PGND [pin 33] - PLL_LF [pin 35] - PLL_MODE0 [pin 38] - PLL_MODE1 [pin 39] - PVDD [pin 34] - RSVD [pin 30] - SCL/CCLK [pin 23] - SDA/COUT [pin 22] - SELFBOOT [pin 6] - VDRIVE [pin 17] - VOUT0 [pin 46] - VOUT1 [pin 45] - VOUT2 [pin 44] - VOUT3 [pin 43] ### U3 — [MUSES72320V-TE2](https://www.flux.ai/adrian95/muses72320v-te2~79g.md) - Part Type: Integrated Circuit - Manufacturer Part Number: MUSES72320V-TE2 - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: http://www.njr.co.jp/products/semicon/PDF/MUSES72320_J.pdf - Manufacturer Name: Nisshinbo Micro Devices Inc. - Role: Volume control **Pins:** - ADR0 [pin 31] - ADR1 [pin 30] - ADR2 [pin 29] - CLOCK [pin 19] - D_CAP [pin 28] - D_REF [pin 21] - D_VDD [pin 17] - DATA [pin 18] - DCCAP_L [pin 8] - DCCAP_R [pin 9] - INL [pin 26] - INR [pin 23] - L_REF_1 [pin 2] - L_REF_2 [pin 4] - L_REF_3 [pin 6] - L- [pin 5] - L+ [pin 3] - LATCH [pin 20] - OUTL [pin 7] - OUTR [pin 10] - R_REF_1 [pin 11] - R_REF_2 [pin 13] - R_REF_3 [pin 15] - R- [pin 12] - R+ [pin 14] - V-_1 [pin 25] - V-_2 [pin 27] - V+_1 [pin 22] - V+_2 [pin 24] - Z/C [pin 32] - Z/C_REFL [pin 1] - Z/C_REFR [pin 16] ### U4 — [OPA2134UA](https://www.flux.ai/jecstronic/opa2134ua~q8s.md) - Manufacturer Name: Texas Instruments - Role: Output buffer - Part Type: Operational Amplifier (OP-AMP) - Manufacturer Part Number: OPA2134UA - Datasheet URL: https://www.ti.com/general/docs/suppproductinfo.tsp?distId=10&gotoUrl=https%3A%2F%2Fwww.ti.com%2Flit%2Fgpn%2Fopa134 **Pins:** - -IN A [pin 2] - -IN B [pin 6] - +IN A [pin 3] - +IN B [pin 5] - OUT A [pin 1] - OUT B [pin 7] - V- [pin 4] - V+ [pin 8] ### U5 — [CH32V003F4U6](https://www.flux.ai/vasyl/ch32v003f4u6~a3.md) - LCSC Part Number: C5299908 - Package or Case Code: 20-QFN - Datasheet URL: http://www.wch-ic.com/downloads/CH32V003DS0_PDF.html - Role: MCU control - Manufacturer Name: WCH - Manufacturer Part Number: CH32V003F4U6 - Part Type: Microcontroller - Package: 20-QFN - Role Details: MCU control; package verified as WCH CH32V003F4U6 QFN20 3.0x3.0 mm, 0.4 mm pitch, exposed pad ~1.7-1.8 mm. Previous PCB inspection showed overlapping exposed-pad/paste geometry, so footprint should use a single EP copper/mask with windowed paste only. - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - PA1/OSCI [pin 2] - PA2/OSCO [pin 3] - PC0/T2 [pin 7] - PC1/SDA [pin 8] - PC2/SCL [pin 9] - PC3/T1 [pin 10] - PC4/A2 [pin 11] - PC5/SCK [pin 12] - PC6/MOSI [pin 13] - PC7/MISO [pin 14] - PD0/T1 [pin 5] - PD1/SWIO [pin 15] - PD2/A3 [pin 16] - PD3/A4 [pin 17] - PD4/A7 [pin 18] - PD5/A5 [pin 19] - PD6/A6 [pin 20] - PD7/NRST [pin 1] - VDD [pin 6] - VSS [pin 4] - VSS [pin 21] ### X1 — [ABM3B-26.000MHZ-B2-T](https://www.flux.ai/jecstronic/abm3b-26p000mhz-b2-t~b1n.md) - Datasheet URL: https://abracon.com/Resonators/abm3b.pdf - Role: Signal Generation - Manufacturer Name: Abracon - Part Type: Oscillator - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: ABM3B-12.288MHZ-B2-T - Role Details: 12.288 MHz ADAU1701 crystal clock source **Pins:** - 1 [pin 1] - 3 [pin 3] - GND_1 [pin 2] - GND_2 [pin 4] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/pjwjanssen/modular-high-end-audio-preamp~7g](https://www.flux.ai/pjwjanssen/modular-high-end-audio-preamp~7g).* --- *Generated from [https://www.flux.ai/pjwjanssen/modular-high-end-audio-preamp~7g](https://www.flux.ai/pjwjanssen/modular-high-end-audio-preamp~7g)*