Eurorack State-Variable Filter
Eurorack State-Variable Filter is an open source PCB design by Len42: a 2-layer, 50.5 × 102.9 mm board with 68 components (33 distinct parts). It is built around the CEM3320, TL074, TL072. Filed under audio.
Eurorack synthesizer module designs
A state-variable filter using the CEM3320 chip
This module requires a 16-pin Eurorack power cable, but it does not depend on +5V power from the Eurorack system.
First, adjust the "DC TRIM" trimmer (RV8) to minimize control voltage feedthrough. - Disconnect all inputs from the module. - Set the cutoff and resonance controls fully counter-clockwise. - Connect an audio signal (e.g. from a VCO) to the module's volt-per-octave CV input. - Connect either of the the module's outputsj to an oscilloscope, or just listen to it. - Adjust RV8 for the minimum output signal.
Built around
Parts list
68 components, 33 distinct parts — part numbers from the project's BOM.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | CEM3320 Curtis Electromusic | DIP-18_W7.62mm | U1 |
| 1 | TL074 Texas Instruments | DIP-14_W7.62mm | U2 |
| 1 | TL072 Texas Instruments | DIP-8_W7.62mm | U3 |
| 6 | WQP-PJ398 QingPu / Thonk | Jack_3.5mm_QingPu_WQP-PJ398SM_Vertical | J1, J2, J3, J4, J5, J6 |
| 1 | CONN_EURORACK_16 Conn_Eurorack_16 Wurth Elektronik | IDC-Header-Eurorack-16-TH | J9 |
| 1 | Conn_Front_Left_Top | PinSocket_1x15_P2.54mm_Vertical | J10 |
| 1 | Conn_Back_Right_Top | PinHeader_1x15_P2.54mm_Vertical | J11 |
| 1 | CV-BUS | PinHeader_1x03_P2.54mm_Vertical | JP1 |
| 3 | 100K Alpha | Potentiometer_Alpha_RD901F-40-00D_Single_Vertical | RV1, RV3, RV5 |
| 2 | 100K Song Huei | Potentiometer_SongHuei_Single_Vertical | RV2, RV4 |
| 1 | 25K Bourns | Potentiometer_Bourns_3296WY_Vertical | RV6 |
| 1 | 10K Bourns | Potentiometer_Bourns_3296WY_Vertical | RV7 |
| 1 | 2K Bourns | Potentiometer_Bourns_3296WY_Vertical | RV8 |
| 2 | 10U Panasonic | CP_Radial_D4.0mm_P2.50mm | C1, C2 |
| 6 | 100N TDK | C_Disc_D5.0mm_W2.5mm_P2.50mm | C3, C4, C5, C6, C9, C10 |
| 3 | 4U7 Panasonic | CP_Radial_D4.0mm_P2.50mm | C7, C13, C15 |
| 1 | 10P TDK | C_Disc_D5.0mm_W2.5mm_P2.50mm | C8 |
| 1 | 18P Murata | C_Disc_D5.0mm_W2.5mm_P2.50mm | C11 |
| 2 | 150P KEMET | C_Rect_L7.2mm_W4.5mm_P5.00mm | C12, C14 |
| 1 | 200K YAGEO | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1 |
Show 13 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | 130K YAGEO | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R2 |
| 16 | 100K YAGEO | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R3, R4, R6, R7, R9, R10, R11, R12 +8 |
| 1 | 120K YAGEO | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R5 |
| 2 | 68K YAGEO | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R8, R27 |
| 1 | 47K YAGEO | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R13 |
| 2 | 91K YAGEO | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R14, R24 |
| 1 | 300K YAGEO | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R15 |
| 1 | 240K YAGEO | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R17 |
| 1 | 220K YAGEO | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R18 |
| 1 | 2M61 YAGEO | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R21 |
| 1 | 680R YAGEO | R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R22 |
| 1 | 1M YAGEO | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R26 |
| 2 | 1K Vishay / Dale | R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R31, R32 |
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