

HackableDelay
A hackable delay circuit for eurorack modular synthesizers, designed in KiCad.
- Size
- 86.4 × 58.4 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 65
- Nets
- 41
- Pads
- 161
- Tracks, vias
- 178, 0
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 30 Jun 2026
- Updated
- 27 Aug 2026
Overview
HackableDelay is an open-source printed circuit board by benjiaomodular, from the benjiaomodular/HackableDelay repository on GitHub. It is a 2-layer board of 86.4 × 58.4 mm with 65 parts on 41 nets, routed with 178 tracks and 0 vias.
It is built around the PT2399, TL072 and LM1117T-5.0. Its parts include 23 capacitors, 20 resistors, 5 connectors, 3 ICs and 1 diode.
Main components
3PT2399
DIP-16Processor DIP-16 Audio Interface ICs ROHSPTCAudio Interface ICsTL072
SOP-8-18V~18V 0℃~+70℃ 1.4mA 1.5nA 10V/us 10mV 2 2.5nA 3MHz 85dB SOP-8 Operational Amplifier ROHSGcoreOperational AmplifierLM1117T-5.0
TO-220-40℃~+125℃@(Tj) 0.003%Vout 1 1.3V@(1A) 10mA 15V 1A 5V 75dB@(120Hz) Fixed Over Current Protection、Thermal shutdown Positive TO-220 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSHGSEMIVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
README
README.mdHackable Delay
A hackable delay circuit for eurorack modular synthesizers, designed in KiCad.
![]()
Files
HackableDelay.kicad_sch— schematicHackableDelay.kicad_pcb— PCB layoutHackableDelay.kicad_pro— KiCad project file
Schematic

Tools
- KiCad 8.x or later
Fabrication
The Fabrication folder contains ready-to-order Gerber/drill packages (e.g. HackableDelay v1.1.zip) for the PCB itself. To get a working module you'll also need panel graphics and a parts order.
Ordering the PCB
- Download the zip for the version you want to build from
Fabrication/. - Upload it as-is to your fab of choice (e.g. JLCPCB, PCBWay) — no need to unzip, most fab houses accept the zip directly.
- Recommended settings: 2 layers, 1.6mm thickness, HASL or ENIG finish. Silkscreen/soldermask color is up to you.
- The zip includes:
*-F_Cu.gbr/*-B_Cu.gbr— copper layers*-F_Mask.gbr/*-B_Mask.gbr— soldermask*-F_Silkscreen.gbr/*-B_Silkscreen.gbr— silkscreen*-Edge_Cuts.gbr— board outline*-PTH.drl/*-NPTH.drl— plated/non-plated drill files*-job.gbrjob— job file describing the stackup
Panel graphics
HackableDelay - Front Graphics.svg and HackableDelay - Back Graphics.svg are the faceplate/panel artwork. Individual layer previews (copper, mask, paste, silkscreen, edge cuts) are also available as SVGs in SVG/ if you want to inspect or edit specific layers.
Bill of materials
HackableDelay - BOM.csv lists all components with references, values, footprints, and quantities. HackableDelay - BOM with Shopee Links.xlsx is the same BOM with sourcing links (Philippines/Shopee-specific — substitute equivalents from your preferred supplier). An HTML version is available in bom/.
Older versions
Previous board revisions are kept under Legacy Versions/ for reference; use the files in the repo root and Fabrication/ for the current version unless you specifically need an older layout.
License
Creative Commons Attribution 4.0 International (CC BY 4.0)
You are free to share and adapt this design for any purpose, including commercially, as long as you give appropriate credit.
© Benjie Jiao x SOMATOSONIC / benjiaomodular
Parts
65| Qty | Value | Footprint | References |
|---|---|---|---|
| 9 | 10k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R2, R3, R5, R6, R7, R9, R10, R11, R17 |
| 4 | 100nF | Capacitor_THT:C_Rect_L7.0mm_W3.5mm_P5.00mm | C2, C4, C8, C9 |
| 4 | 1uF | Capacitor_THT:CP_Radial_D6.3mm_P2.50mm | C13, C17, C19, C23 |
| 4 | MountingHole_Pad | MountingHole:MountingHole_3.2mm_M3_Pad_TopBottom | H1, H2, H3, H4 |
| 3 | 1k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1, R13, R19 |
| 3 | 20k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R8, R14, R15 |
| 3 | B100K | benjiaomodular:PinHeader_1x03_P2.54mm_Vertical | LEVEL1, REPEATS1, TIME1 |
| 3 | SolderJumper_2_Bridged | Jumper:SolderJumper-2_P1.3mm_Bridged_Pad1.0x1.5mm | JP1, JP2, JP3 |
| 2 | 10nF | Capacitor_THT:C_Rect_L7.0mm_W3.5mm_P5.00mm | C15, C18 |
| 2 | 10uF | Capacitor_THT:CP_Radial_D6.3mm_P2.50mm | C6, C12 |
| 2 | 2.2nF | Capacitor_THT:C_Rect_L7.0mm_W3.5mm_P5.00mm | C10, C11 |
| 2 | 4.7nF | Capacitor_THT:C_Rect_L7.0mm_W3.5mm_P5.00mm | C14, C16 |
| 2 | 47uF | Capacitor_THT:CP_Radial_D6.3mm_P2.50mm | C1, C5 |
| 2 | Conn_01x02_Pin | benjiaomodular:SolderPads_1x02_P2.54mm | MOD1, MOD2 |
| 2 | Conn_01x03_Pin | benjiaomodular:SolderPads_1x03_P2.54mm | J4, J5 |
| 1 | 100k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R20 |
| 1 | 100pF | Capacitor_THT:C_Rect_L7.0mm_W3.5mm_P5.00mm | C20 |
| 1 | 1M | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R4 |
| 1 | 2.7k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R12 |
| 1 | 22nF | Capacitor_THT:C_Rect_L7.0mm_W3.5mm_P5.00mm | C21 |
| 1 | 22pF | Capacitor_THT:C_Rect_L7.0mm_W3.5mm_P5.00mm | C7 |
| 1 | 2k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R18 |
| 1 | 4.7uF | Capacitor_THT:CP_Radial_D6.3mm_P2.50mm | C3 |
| 1 | 47nF | Capacitor_THT:C_Rect_L7.0mm_W3.5mm_P5.00mm | C22 |
| 1 | 5.1k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R16 |
| 1 | B1M | benjiaomodular:PinHeader_1x03_P2.54mm_Vertical | GAIN1 |
| 1 | INPUT | benjiaomodular:PinHeader_1x02_P2.54mm_Vertical | J2 |
| 1 | Jack-DC | benjiaomodular:PinHeader_1x02_P2.54mm_Vertical | J1 |
| 1 | LED | LED_THT:LED_D5.0mm | D1 |
| 1 | LM1117T-5.0 | Package_TO_SOT_THT:TO-220-3_Vertical | U3 |
| 1 | OUTPUT | benjiaomodular:PinHeader_1x02_P2.54mm_Vertical | J3 |
| 1 | PT2399 | Package_DIP:DIP-16_W7.62mm_Socket_LongPads | U2 |
| 1 | TL072 | Package_DIP:DIP-8_W7.62mm_Socket_LongPads | U1 |
Questions
How big is the HackableDelay PCB?
It measures 86.4 × 58.4 mm and has 2 copper layers, 1.6 mm thick.
What parts does the HackableDelay use?
65 parts, built around the PT2399, TL072 and LM1117T-5.0. 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 HackableDelay KiCad files?
From the benjiaomodular/HackableDelay repository on GitHub, at the commit this page was made from: the board is Legacy Versions/v1.0/HackableDelay.kicad_pcb and its schematic HackableDelay.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the HackableDelay design in my own project?
Its repository states no licence, so its author keeps all rights: ask benjiaomodular before reusing the design.
Similar boards
- 2 layers170.3 × 151.7 mm

- 2 layers192.7 × 104.5 mm

Delay
MatthewATaylor/Modular-Synth-Hardware
KiCad schematics and PCB layouts for my modular synth
186 parts11MIT - 2 layers161.3 × 263.9 mm

DSP 1.1
Owen-Patrick/SoftSynthetics-DSP
Hardware for adapting Karaoke DSP board to eurorack
115 parts10 - 2 layers61 × 114.9 mm

BoyInWell
CuriousMotor/MoonRock-Delay-Pedal
A PCB for simple PT2399 based delay effect guitar pedal based on Boy In Well.
63 parts3GPL-3.0 - 2 layers50 × 100 mm

- 2 layers58.4 × 57.2 mm

Sea Urchin Guitar Pedal
sarreola07/Sea_Urchin_Guitar_Pedal
An analog dry path blended with a digital delay line built around the PT2399 echo processor. TL072 op-amps handle input/output buffering, a 78L05 regulates the PT2399 supply, and the signal path is biased at 4.5 V.
64 parts1 - 2 layers100 × 80 mm

- 2 layers100 × 100 mm
