2 layers47.5 × 43 mm
2 layers115 × 47 mm
Penfold ADSR
ali5ter/Penfold_ADSR🎛️ R.A. Penfold's ADSR design adapted as a Eurorack powered module
- Size
- 115 × 47 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 47
- Nets
- 40
- Pads
- 135
- Tracks, vias
- 192, 2
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 4 Jul 2023
- Updated
- 28 Apr 2026
Overview
Penfold ADSR is an open-source printed circuit board by ali5ter, from the ali5ter/Penfold_ADSR repository on GitHub, published under the MIT licence. It is a 2-layer board of 115 × 47 mm with 47 parts on 40 nets, routed with 192 tracks and 2 vias.
It is built around the CA3240E, BC547 and BC557. Its parts include 19 resistors, 7 transistors, 6 capacitors, 3 connectors and 2 ICs. It belongs with the audio and music boards of this library.
Main components
3
CA3240E
PDIP-8-18V~-2V、2V~18V -40℃~+85℃ 0.5pA 10pA 15uV/℃ 2 20mA 4.5MHz 40nV/√Hz@1kHz 4V~36V 5mV 8mA 90dB 9V/us Built-in compensation PDIP-8 Operational AmplifierRenesas ElectronicsOperational Amplifier
BC547
TO-92Bipolar (BJT)Jiangsu Changjing Electronics Technology (CJ)BC557
TO-921 PNP 100mA 100nA 150MHz 45V 500mW 6V 800 90mV、250mV PNP TO-92 Bipolar (BJT) ROHSDDFBipolar (BJT)
README
README.md⚠️ Archived 2025-08-25. No longer maintained.
Penfold_ADSR
KiCad project for the circuit and PCB of R.A. Penfolds ADSR design which I adapted as a Eurorack powered module. The original circuit is taken from the book, "Electronic Synthesiser Construction" by R. A. Penfold, published by Babani in 1986.
I have kept to the original design as much as possible but added power and switched INT.Gate via a Eurorack spec bus.
I have yet to manufacture and test this circuit.
Parts
47| Qty | Value | Footprint | References |
|---|---|---|---|
| 8 | 10K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R2, R4, R5, R6, R9, R10, R15, R17 |
| 6 | 6.8K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R7, R8, R11, R13, R14, R19 |
| 5 | BC547 | Package_TO_SOT_THT:TO-92_Inline | Q2, Q3, Q4, Q6, Q7 |
| 4 | MountingHole | MountingHole:MountingHole_3.2mm_M3 | H1, H2, H3, H4 |
| 3 | 2.2M | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | RV1, RV2, RV4 |
| 2 | 100K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R16, R18 |
| 2 | 100nF | Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P5.00mm | C3, C6 |
| 2 | 10uF | Capacitor_THT:CP_Radial_D5.0mm_P2.00mm | C1, C2 |
| 2 | 1N4007 | Diode_THT:D_DO-41_SOD81_P10.16mm_Horizontal | D1, D2 |
| 2 | 22K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R3, R12 |
| 2 | BC557 | Package_TO_SOT_THT:TO-92_Inline | Q1, Q5 |
| 1 | 100K | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | RV3 |
| 1 | 1K | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R1 |
| 1 | 2.2uF | Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm | C5 |
| 1 | 4.7nF | Capacitor_THT:C_Disc_D5.0mm_W2.5mm_P2.50mm | C4 |
| 1 | 4001 | Package_DIP:DIP-14_W7.62mm_LongPads | U1 |
| 1 | CA3240E | Package_DIP:DIP-8_W7.62mm_LongPads | U2 |
| 1 | Eurorack style bus | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | J1 |
| 1 | Input breakout | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | J2 |
| 1 | Output breakout | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | J4 |
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Questions
How big is the Penfold ADSR PCB?
It measures 115 × 47 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Penfold ADSR use?
47 parts, built around the CA3240E, BC547 and BC557. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Penfold ADSR KiCad files?
From the ali5ter/Penfold_ADSR repository on GitHub, at the commit this page was made from: the board is Penfold_ADSR.kicad_pcb and its schematic Penfold_ADSR.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Penfold ADSR design in my own project?
Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).