# VCA Audio Compressor ## Description This is a diode-based VCA audio compressor that works in mono. The compressor has LED-based gain reduction metering, input gain (preamp), output gain, and a fast-attack switch akin to the SSL channel-strip compressors. The module is to be powered by a regular outlet so it has an AC-DC converter. ## Project Details - **Owner:** olasubomiborishade - **Created:** 8/12/2024 - **Last Updated:** 4/8/2026 - **Visibility:** Public - **Copies:** 1 ## Key Components ### 1 Buffer || 2 VCA — [TL072MJG](https://www.flux.ai/jecstronic/tl072mjg~4ri.md) - Manufacturer Part Number: TL072MJG - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Operational Amplifier (OP-AMP) - Manufacturer Name: Texas Instruments - Datasheet URL: https://www.ti.com/general/docs/suppproductinfo.tsp?distId=26&gotoUrl=https://www.ti.com/lit/gpn/tl072m **Pins:** - 1IN- [pin 2] - 1IN+ [pin 3] - 1OUT [pin 1] - 2IN- [pin 6] - 2IN+ [pin 5] - 2OUT [pin 7] - VCC- [pin 4] - VCC+ [pin 8] ### 1 Comparator || 2 Control Voltage — [TL072MJG](https://www.flux.ai/jecstronic/tl072mjg~4ri.md) - Datasheet URL: https://www.ti.com/general/docs/suppproductinfo.tsp?distId=26&gotoUrl=https://www.ti.com/lit/gpn/tl072m - Manufacturer Name: Texas Instruments - Manufacturer Part Number: TL072MJG - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Operational Amplifier (OP-AMP) **Pins:** - 1IN- [pin 2] - 1IN+ [pin 3] - 1OUT [pin 1] - 2IN- [pin 6] - 2IN+ [pin 5] - 2OUT [pin 7] - VCC- [pin 4] - VCC+ [pin 8] ### 1 Peak Detector || 2 Full-wave Rectifier || 3 VCA Output Correction || 4 Make-up Gain — [TL074CD](https://www.flux.ai/jecstronic/tl074cd~x1b.md) - Datasheet URL: https://www.ti.com/general/docs/suppproductinfo.tsp?distId=10&gotoUrl=http%3A%2F%2Fwww.ti.com%2Flit%2Fgpn%2Ftl071a - Manufacturer Name: Texas Instruments - Part Type: Operational Amplifier (OP-AMP) - Manufacturer Part Number: TL074CD **Pins:** - -IN 1 [pin 2] - -IN 2 [pin 6] - -IN 3 [pin 9] - -IN 4 [pin 13] - +IN 1 [pin 3] - +IN 2 [pin 5] - +IN 3 [pin 10] - +IN 4 [pin 12] - OUT 1 [pin 1] - OUT 2 [pin 7] - OUT 3 [pin 8] - OUT 4 [pin 14] - V- [pin 11] - V+ [pin 4] ### AC-DC Power Converter — [IRM-20-12](https://www.flux.ai/adrian95/irm-20-12~hi.md) - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: ACDC - Manufacturer Name: MEAN WELL USA Inc. - Datasheet URL: https://www.meanwellusa.com/upload/pdf/IRM-20/IRM-20-spec.pdf - Manufacturer Part Number: IRM-20-12 **Pins:** - -Vo [pin 3] - +Vo [pin 4] - AC/L [pin 1] - AC/N [pin 2] ### Attack — [3590S-2-103L](https://www.flux.ai/jecstronic/3590s-2-103l~l7g.md) - Manufacturer Name: Bourns Inc. - Resistance: 1MΩ - Manufacturer Part Number: 3590S-2-103L - Part Type: Potentiometer - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://www.bourns.com/docs/Product-Datasheets/3590.pdf **Pins:** - CCW [pin 1] - CW [pin 3] - WIPER [pin 2] ### Attack Mode Switch — [A101SYCQ04](https://www.flux.ai/jecstronic/a101sycq04~njs.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: TE Connectivity / Alcoswitch - Part Type: Switch - Datasheet URL: https://www.mouser.ca/datasheet/2/418/5/ENG_CD_1825136_A8-660112.pdf - Manufacturer Part Number: A101SYCQ04 **Pins:** - ~ [pin 1] - ~ [pin 3] - ~ [pin 2] ### D1 — [1N4148WS-7](https://www.flux.ai/jecstronic/1n4148ws-7~ei.md) - Manufacturer Name: SMC Diode Solutions - Manufacturer Part Number: 1N4148WS-7 - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://www.mouser.com/datasheet/2/308/1N914BWS-D-1801390.pdf - Part Type: Diode **Pins:** - A [pin 2] - K [pin 1] ### D10 — [1N4148WS-7](https://www.flux.ai/jecstronic/1n4148ws-7~ei.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: SMC Diode Solutions - Manufacturer Part Number: 1N4148WS-7 - Part Type: Diode - Datasheet URL: https://www.mouser.com/datasheet/2/308/1N914BWS-D-1801390.pdf **Pins:** - A [pin 2] - K [pin 1] ### D11 — [1N4148WS-7](https://www.flux.ai/jecstronic/1n4148ws-7~ei.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 1N4148WS-7 - Manufacturer Name: SMC Diode Solutions - Datasheet URL: https://www.mouser.com/datasheet/2/308/1N914BWS-D-1801390.pdf - Part Type: Diode **Pins:** - A [pin 2] - K [pin 1] ### D12 — [1N5822](https://www.flux.ai/adrian95/1n5822~4xv.md) - Part Type: Diode - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 1N5822 - Datasheet URL: https://www.mouser.com/datasheet/2/268/LDS_0303-1592924.pdf - Manufacturer Name: STMicroelectronics **Pins:** - A [pin 2] - K [pin 1] ### D16 — [1N4148WS-7](https://www.flux.ai/jecstronic/1n4148ws-7~ei.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 1N4148WS-7 - Manufacturer Name: SMC Diode Solutions - Part Type: Diode - Datasheet URL: https://www.mouser.com/datasheet/2/308/1N914BWS-D-1801390.pdf **Pins:** - A [pin 2] - K [pin 1] ### D17 — [1N4148WS-7](https://www.flux.ai/jecstronic/1n4148ws-7~ei.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: SMC Diode Solutions - Manufacturer Part Number: 1N4148WS-7 - Part Type: Diode - Datasheet URL: https://www.mouser.com/datasheet/2/308/1N914BWS-D-1801390.pdf **Pins:** - A [pin 2] - K [pin 1] ### D18 — [LED](https://www.flux.ai/jharwinbarrozo/led-tht~gr.md) - Series Resistance: 0.42Ω - Breakdown Voltage: 0V - Emission Coefficient: 3.73 - Forward Voltage: 1.70 - Saturation Current: 93.2e-12A **Pins:** - A [pin 2] - K [pin 1] ### D19 — [LED](https://www.flux.ai/jharwinbarrozo/led-tht~gr.md) - Series Resistance: 0.42Ω - Breakdown Voltage: 0V - Emission Coefficient: 3.73 - Forward Voltage: 1.70 - Saturation Current: 93.2e-12A **Pins:** - A [pin 2] - K [pin 1] ### D2 — [1N4148WS-7](https://www.flux.ai/jecstronic/1n4148ws-7~ei.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: SMC Diode Solutions - Manufacturer Part Number: 1N4148WS-7 - Part Type: Diode - Datasheet URL: https://www.mouser.com/datasheet/2/308/1N914BWS-D-1801390.pdf **Pins:** - A [pin 2] - K [pin 1] ### D20 — [LED](https://www.flux.ai/jharwinbarrozo/led-tht~gr.md) - Forward Voltage: 1.70 - Saturation Current: 93.2e-12A - Series Resistance: 0.42Ω - Breakdown Voltage: 0V - Emission Coefficient: 3.73 **Pins:** - A [pin 2] - K [pin 1] ### D21 — [LED](https://www.flux.ai/jharwinbarrozo/led-tht~gr.md) - Series Resistance: 0.42Ω - Breakdown Voltage: 0V - Emission Coefficient: 3.73 - Forward Voltage: 1.70 - Saturation Current: 93.2e-12A **Pins:** - A [pin 2] - K [pin 1] ### D3 — [1N4148WS-7](https://www.flux.ai/jecstronic/1n4148ws-7~ei.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 1N4148WS-7 - Manufacturer Name: SMC Diode Solutions - Datasheet URL: https://www.mouser.com/datasheet/2/308/1N914BWS-D-1801390.pdf - Part Type: Diode **Pins:** - A [pin 2] - K [pin 1] ### D4 — [1N4148WS-7](https://www.flux.ai/jecstronic/1n4148ws-7~ei.md) - Manufacturer Part Number: 1N4148WS-7 - Manufacturer Name: SMC Diode Solutions - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Diode - Datasheet URL: https://www.mouser.com/datasheet/2/308/1N914BWS-D-1801390.pdf **Pins:** - A [pin 2] - K [pin 1] ### D5 — [1N4148WS-7](https://www.flux.ai/jecstronic/1n4148ws-7~ei.md) - Part Type: Diode - Datasheet URL: https://www.mouser.com/datasheet/2/308/1N914BWS-D-1801390.pdf - Manufacturer Part Number: 1N4148WS-7 - Manufacturer Name: SMC Diode Solutions - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - A [pin 2] - K [pin 1] ### D6 — [1N4148WS-7](https://www.flux.ai/jecstronic/1n4148ws-7~ei.md) - Part Type: Diode - Datasheet URL: https://www.mouser.com/datasheet/2/308/1N914BWS-D-1801390.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: SMC Diode Solutions - Manufacturer Part Number: 1N4148WS-7 **Pins:** - A [pin 2] - K [pin 1] ### D7 — [1N4148WS-7](https://www.flux.ai/jecstronic/1n4148ws-7~ei.md) - Manufacturer Part Number: 1N4148WS-7 - Manufacturer Name: SMC Diode Solutions - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Diode - Datasheet URL: https://www.mouser.com/datasheet/2/308/1N914BWS-D-1801390.pdf **Pins:** - A [pin 2] - K [pin 1] ### D8 — [1N4148WS-7](https://www.flux.ai/jecstronic/1n4148ws-7~ei.md) - Datasheet URL: https://www.mouser.com/datasheet/2/308/1N914BWS-D-1801390.pdf - Part Type: Diode - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: SMC Diode Solutions - Manufacturer Part Number: 1N4148WS-7 **Pins:** - A [pin 2] - K [pin 1] ### D9 — [1N4148WS-7](https://www.flux.ai/jecstronic/1n4148ws-7~ei.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 1N4148WS-7 - Manufacturer Name: SMC Diode Solutions - Part Type: Diode - Datasheet URL: https://www.mouser.com/datasheet/2/308/1N914BWS-D-1801390.pdf **Pins:** - A [pin 2] - K [pin 1] ### Input Gain — [3590S-2-103L](https://www.flux.ai/jecstronic/3590s-2-103l~l7g.md) - Datasheet URL: https://www.bourns.com/docs/Product-Datasheets/3590.pdf - Part Type: Potentiometer - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 3590S-2-103L - Manufacturer Name: Bourns Inc. - Resistance: 20kΩ **Pins:** - CCW [pin 1] - CW [pin 3] - WIPER [pin 2] ### Inverter — [LM2577SX-ADJ/NOPB](https://www.flux.ai/jecstronic/lm2577sx-adjnopb~qdd.md) - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Integrated Circuit - Manufacturer Name: Texas Instruments - Manufacturer Part Number: LM2577SX-ADJ/NOPB - Datasheet URL: https://rocelec.widen.net/view/pdf/puutei9dmi/NATLS13285-1.pdf **Pins:** - COMP [pin 1] - EPAD [pin 6] - FEEDBACK [pin 2] - GND [pin 3] - SW [pin 4] - VIN [pin 5] ### J1 — [SJ-3523-SMT-TR](https://www.flux.ai/vasy_skral/sj-3523-smt-tr~6n4.md) - Datasheet URL: https://www.cuidevices.com/product/resource/sj-352x-smt.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: SJ-3523-SMT-TR - Part Type: Connector - Manufacturer Name: CUI Devices **Pins:** - R [pin R] - S [pin S] - T [pin T] ### J2 — [SJ-3523-SMT-TR](https://www.flux.ai/vasy_skral/sj-3523-smt-tr~6n4.md) - Datasheet URL: https://www.cuidevices.com/product/resource/sj-352x-smt.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: CUI Devices - Manufacturer Part Number: SJ-3523-SMT-TR - Part Type: Connector **Pins:** - R [pin R] - S [pin S] - T [pin T] ### Output Gain — [3590S-2-103L](https://www.flux.ai/jecstronic/3590s-2-103l~l7g.md) - Manufacturer Part Number: 3590S-2-103L - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Potentiometer - Manufacturer Name: Bourns Inc. - Resistance: 100kΩ - Datasheet URL: https://www.bourns.com/docs/Product-Datasheets/3590.pdf **Pins:** - CCW [pin 1] - CW [pin 3] - WIPER [pin 2] ### Q5 — [2N3904](https://www.flux.ai/adrian95/2n3904~a6d.md) - Part Type: Transistor - Manufacturer Part Number: 2N3904 - Manufacturer Name: NTE Electronics, Inc - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://www.nteinc.com/specs/original/2N3904.pdf **Pins:** - B [pin 2] - C [pin 3] - E [pin 1] ### Q6 — [2N3904](https://www.flux.ai/adrian95/2n3904~a6d.md) - Manufacturer Name: NTE Electronics, Inc - Datasheet URL: https://www.nteinc.com/specs/original/2N3904.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Transistor - Manufacturer Part Number: 2N3904 **Pins:** - B [pin 2] - C [pin 3] - E [pin 1] ### Q7 — [2N3904](https://www.flux.ai/adrian95/2n3904~a6d.md) - Part Type: Transistor - Manufacturer Part Number: 2N3904 - Manufacturer Name: NTE Electronics, Inc - Datasheet URL: https://www.nteinc.com/specs/original/2N3904.pdf - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - B [pin 2] - C [pin 3] - E [pin 1] ### Q8 — [2N3904](https://www.flux.ai/adrian95/2n3904~a6d.md) - Manufacturer Name: NTE Electronics, Inc - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://www.nteinc.com/specs/original/2N3904.pdf - Part Type: Transistor - Manufacturer Part Number: 2N3904 **Pins:** - B [pin 2] - C [pin 3] - E [pin 1] ### Ratio — [3590S-2-103L](https://www.flux.ai/jecstronic/3590s-2-103l~l7g.md) - Datasheet URL: https://www.bourns.com/docs/Product-Datasheets/3590.pdf - Manufacturer Part Number: 3590S-2-103L - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Potentiometer - Manufacturer Name: Bourns Inc. - Resistance: 100kΩ **Pins:** - CCW [pin 1] - CW [pin 3] - WIPER [pin 2] ### Release — [3590S-2-103L](https://www.flux.ai/jecstronic/3590s-2-103l~l7g.md) - Resistance: 1MΩ - Manufacturer Name: Bourns Inc. - Manufacturer Part Number: 3590S-2-103L - Part Type: Potentiometer - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://www.bourns.com/docs/Product-Datasheets/3590.pdf **Pins:** - CCW [pin 1] - CW [pin 3] - WIPER [pin 2] ### Threshold — [3590S-2-103L](https://www.flux.ai/jecstronic/3590s-2-103l~l7g.md) - Datasheet URL: https://www.bourns.com/docs/Product-Datasheets/3590.pdf - Manufacturer Part Number: 3590S-2-103L - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Potentiometer - Manufacturer Name: Bourns Inc. - Resistance: 10kΩ **Pins:** - CCW [pin 1] - CW [pin 3] - WIPER [pin 2] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/olasubomiborishade/vca-audio-compressor~vv](https://www.flux.ai/olasubomiborishade/vca-audio-compressor~vv).* --- *Generated from [https://www.flux.ai/olasubomiborishade/vca-audio-compressor~vv](https://www.flux.ai/olasubomiborishade/vca-audio-compressor~vv)*