Backyard Brains SpikerBox — Open-Source Neuroscience Bioamplifier
This lab introduces students to the fundamentals of neuroscience and electrophysiology through the construction and use of an open-source bioamplifier. Students assemble a circuit designed to detect and amplify the tiny electrical signals, known as action potentials or spikes, generated by the neurons of insects such as crickets or cockroaches. By building the SpikerBox, students learn about analog signal conditioning, including the use of instrumentation amplifiers for high-impedance biological inputs and audio power amplifiers for real-time auditory feedback. Once the device is assembled, learners use electrodes to record neural activity and analyze the results using external recording software, gaining hands-on experience in biological signal processing and the intersection of electronics and biology.
Uploaded by demo on 2026-07-19 · ready · Electronics · Original source ↗
Files: SpikerBox_schematic.tif · SpikerBox_build_guide.docx · SpikerBox_board_v1.brd · SpikerBox_board_v2.brd · SpikerBox_board_v3.brd · NSF_ATE_provenance.txt
Readiness checks
Latest report — 2026-07-19 15:53
Readiness: Backyard Brains SpikerBox — Open-Source Neuroscience Bioamplifier
Verdict: Ready with caveats · 2026-07-19 · est. parts cost $63–$110
The SpikerBox remains implementable, particularly for through-hole versions v1 and v2, which utilize standard DIP-8 components. This cold check establishes the baseline but identifies that the v3 design is at risk due to the total obsolescence of the specified thumbwheel potentiometer and a housing mismatch for the status LED. Sourcing for several through-hole mechanical parts (RCA jack, resistors) must shift to secondary distributors like Mouser as DigiKey stock has depleted.
Action required
| Part | Problem | Recommended action |
|---|---|---|
| R1-R5 (Axial) | Specified Panasonic series is largely discontinued. | Substitute with generic 1/4W 1% metal film axial resistor kits. |
| RCJ-014 | Zero stock at DigiKey. | Source from Mouser Electronics. |
| SSF-LXH104GD | Zero stock at DigiKey; housing is 5mm (mismatch). | Use substitute SSF-LXH103GD (3mm). |
| EVU-TW7B45C14 | Obsolete; zero stock globally. | Use 3352T-1-103LF; requires v3 PCB footprint modification. |
Parts
Integrated Circuits
| Part | Spec/Package | Status | Stock | Price | Source |
|---|---|---|---|---|---|
| U1 (AD623ANZ) | DIP-8 | Active | 2,409 | $9.04 | DigiKey |
| U2 (LM386N-3/NOPB) | DIP-8 | Active | 1,869 | $1.18 | DigiKey |
| U3 (TLC2272CP) | DIP-8 | Active | 176 | $6.18 | DigiKey |
| U4 (LM567CN/NOPB) | DIP-8 | Active | 874 | $3.18 | DigiKey |
| U5 (TLC2274CN) | DIP-14 | Active | 9,285 | $3.48 | DigiKey |
Passive Components (Resistors)
| Part | Spec/Package | Status | Stock | Price | Source |
|---|---|---|---|---|---|
| R1 (Gain Resistor) | 10 kΩ Axial | Discontinued | — | $0.10 | DigiKey (SMT alternative) |
| R2 | 1 kΩ Axial | Discontinued | — | — | — |
| R3 | 100 kΩ Axial | Discontinued | — | — | — |
| R4 | 68 kΩ Axial | Discontinued | — | — | — |
| R5 | 220 kΩ Axial | Discontinued | — | — | — |
Passive Components (Capacitors)
| Part | Spec/Package | Status | Stock | Price | Source |
|---|---|---|---|---|---|
| C1 (ECA-1EM221) | 220 µF Radial | Active | 5,534 | $0.45 | DigiKey |
| C2 (ECE-A1EN100U) | 10 µF Radial | Active | 6,497 | $0.42 | DigiKey |
| C3 | 0.47 µF Ceramic | Active | Ready | $0.50 | SparkFun |
| C4 | 0.1 µF Ceramic | Active | Ready | $0.10 | DigiKey |
| C5 | 0.22 µF Ceramic | Active | Ready | $0.53 | DigiKey |
| C6 | 0.047 µF Ceramic | Active | Ready | $0.10 | Jameco |
| C7 | 560 pF Ceramic | Active | Ready | $0.11 | DigiKey |
Electromechanical and Connectors
| Part | Spec/Package | Status | Stock | Price | Source |
|---|---|---|---|---|---|
| BATT (BH9V-PC) | 9V PCB Mount | Active | 1,435 | $2.33 | DigiKey |
| J1 (SJ1-3524NG) | 3.5mm Stereo | Active | 14,493 | $1.20 | DigiKey |
| J2 (RCJ-014) | RCA RA PCB | Active | 500 | $1.06 | Mouser |
| LED1 (SSF-LXH104GD) | 3mm/5mm RA | Out of stock | 0 | — | DigiKey |
| SW1 | SPDT RA PCB | Active | 722 | $6.58 | DigiKey |
| EVU-TW7B45C14 | Thumbwheel Pot | Obsolete | 0 | — | — |
Support Hardware
| Part | Spec/Package | Status | Stock | Price | Source |
|---|---|---|---|---|---|
| Electrodes | Stainless Needle | Active | Ready | $4.62 | Acubest |
| Enclosure | Plastic Box | Active | Ready | $2.50 | RS America |
Substitutes
| For part | Substitute | Differences | Judgment |
|---|---|---|---|
| R1-R5 | 1/4W 1% Metal Film Axial | Generic axial kit; matches specs. | Acceptable. |
| SSF-LXH104GD | SSF-LXH103GD | 3mm housing vs 5mm housing; matches snapshot 3mm requirement. | Better match. |
| EVU-TW7B45C14 | 3352T-1-103LF | 9mm top-adjust vs 14mm thumbwheel. | Hard stop: Requires PCB modification. |
Verify any substitute against its datasheet before ordering.
Other dependencies
- PCB Fabrication: Legacy Eagle binary files must be converted to modern XML/Gerber formats before fabrication. Status: not checked.
- Software: Backyard Brains Spike Recorder available as a free download for iOS, Android, Windows, and Mac. Status: Available.
- Cables: 3.5mm male-to-male audio cable required. Status: Available ($1.45).
- Biological Component: Live crickets or cockroaches required. Status: Available ($13.99).
Watch list
- v3 Thumbwheel Potentiometer: This part is completely obsolete. Future v3 builds require a board redesign to accommodate standard 9mm pots.
- TLC2272CP (U3): Stock is currently low (176 units) at the primary distributor.
- PCB File Integrity: Legacy binary Eagle files are increasingly difficult to open without conversion; integrity of conversion should be verified before ordering boards.
Snapshot What the lab depended on when it was uploaded — the baseline the readiness checks research against.
This snapshot tracks the Backyard Brains SpikerBox, an open-source bioamplifier used to detect and amplify neuronal action potentials (spikes) from insects. The design relies on a custom 2-layer PCB and a set of analog integrated circuits, specifically instrumentation and audio amplifiers. It is powered by a 9V battery and outputs via a standard RCA jack or 3.5mm audio jack.
Bill of Materials
This list is reconciled across board versions v1, v2, and v3. Note that v1 and v2 are primarily through-hole, while v3 introduces surface-mount (SMT) variants and additional filtering circuitry.
Integrated Circuits
- U1 (Instrumentation Amplifier): AD623ANZ. Quantity: 1. Package: DIP-8 (DIL08). This is the primary amplifier; it must be a rail-to-rail instrumentation amplifier capable of single-supply operation (9V). Substitution latitude: Low; the pinout and gain characteristics (set by internal resistors and external R1) are specific. Sourcing plan: distributor lookup: AD623ANZ.
- U2 (Audio Power Amplifier): LM386N-3/NOPB. Quantity: 1. Package: DIP-8 (DIL08). Drives the speaker/output. Substitution latitude: High (any LM386 variant in DIP-8 works, though power ratings vary). Sourcing plan: distributor lookup: LM386N-3/NOPB.
- U3 (Dual Op-Amp): TLC2272CP. Quantity: 1. Package: DIP-8 (DIL08). Used for signal conditioning. Substitution latitude: Moderate; requires a rail-to-rail CMOS op-amp for low noise and high input impedance. Sourcing plan: distributor lookup: TLC2272CP.
- U4 (Tone Decoder - v3 only): LM567. Quantity: 1. Package: DIP-8 or SMT variant mentioned in v3 files. Sourcing plan: distributor lookup: LM567CN/NOPB.
- U5 (Quad Op-Amp - v3 only): TLC2274. Quantity: 1. Package: DIP-14 or MSOP-14. Sourcing plan: distributor lookup: TLC2274CN.
Passive Components (Resistors)
All resistors are axial (footprint R0207/10) for v1/v2, likely 1/4W 1% or 5% tolerance.
- R1 (Gain Resistor): 10 kΩ. Quantity: 1. (DigiKey: P10KBACT-ND).
- R2: 1 kΩ. Quantity: 1. (DigiKey: P1.0KBACT-ND).
- R3: 100 kΩ. Quantity: 1. (DigiKey: P100KBACT-ND).
- R4: 68 kΩ. Quantity: 1. (DigiKey: P68KBACT-ND).
- R5: 220 kΩ. Quantity: 1. (DigiKey: P220KCACT-ND).
- Sourcing plan: distributor lookup (representative example): RC1206FR-0710KL (for SMT) or standard axial resistor kits.
Passive Components (Capacitors)
- C1: 220 µF. Quantity: 1. Package: Electrolytic, Radial (E5-10.5). Voltage rating ≥ 16V. Sourcing plan: distributor lookup: ECA-1EM221.
- C2: 10 µF. Quantity: 1. Package: Electrolytic, Radial (E2.5-5). Voltage rating ≥ 16V. Sourcing plan: distributor lookup: ECE-A1EN100U.
- C3: 0.47 µF. Quantity: 1. Package: Ceramic (C050-025X075). Sourcing plan: distributor lookup (spec only): 0.47 µF ceramic capacitor, 25V.
- C4: 0.1 µF. Quantity: 1. Package: Ceramic (C050-024X044). Sourcing plan: distributor lookup (spec only): 0.1 µF ceramic capacitor, 25V.
- C5: 0.22 µF. Quantity: 1. Package: Ceramic (C050-025X075). Sourcing plan: distributor lookup (spec only): 0.22 µF ceramic capacitor, 25V.
- C6: 0.047 µF. Quantity: 1. Package: Ceramic (C050-024X044). Sourcing plan: distributor lookup (spec only): 0.047 µF ceramic capacitor, 25V.
- C7: 560 pF. Quantity: 1. Package: Ceramic (C050-024X044). Sourcing plan: distributor lookup (spec only): 560 pF ceramic capacitor, 50V.
Electromechanical and Connectors
- BATT (Battery Holder): BH9V-PC. Quantity: 1. Package: 9V-BATT (PCB Mount). Substitution latitude: Moderate; requires specific lead spacing for PCB mounting. Sourcing plan: distributor lookup: BH9V-PC.
- J1 (Input Jack): SJ1-3524NG. Quantity: 1. Package: 3.5mm Stereo Jack. Substitution latitude: Low; the PCB footprint is specific to this right-angle jack. Sourcing plan: distributor lookup: SJ1-3524NG.
- J2 (Output Jack): RCJ-014. Quantity: 1. Package: RCA Jack (PCB Mount, Right Angle). Sourcing plan: distributor lookup: RCJ-014.
- LED1 (Status LED): SSF-LXH104GD. Quantity: 1. Package: 3mm Green LED, right-angle housing. Sourcing plan: distributor lookup: SSF-LXH104GD.
- SW1 (Power Switch): 2M1-SP1-T2-B4-M6RE. Quantity: 1. Package: SPDT Toggle Switch (Right Angle, PCB Mount). Sourcing plan: distributor lookup: 2M1-SP1-T2-B4-M6RE.
- Thumbwheel Potentiometer (v3 only): EVU-TW7B45C14. Quantity: 1. Used for volume or gain. Sourcing plan: distributor lookup: EVU-TW7B45C14.
Support Hardware
- Electrodes: Described in build guide as stainless steel needles or thin wires. Substitution latitude: Any conductive stiff wire (e.g., sewing needles). Sourcing plan: retail shopping search: stainless steel acupuncture needles.
- Enclosure: Not explicitly defined by a part number, but board dimensions imply a small plastic project box. Sourcing plan: retail shopping search: small plastic project box for PCB.
Other Temporal Dependencies
- PCB Fabrication: The board is a 2-layer design. The files are in Eagle binary format (pre-v6). These must be converted to modern XML-based Eagle format (.brd) or Gerber files for current fabrication services.
- Software Requirements: The device is analog and does not require firmware. However, the use-case depends on an external recording device (Smartphone or PC). The build guide references "Backyard Brains Spike Recorder" software.
- External Download: Spike Recorder app (available on iOS App Store, Google Play, and Windows/Mac). Sourcing plan: retail shopping search: Backyard Brains Spike Recorder app.
- Cables: Requires a 3.5mm male-to-male audio cable to connect to a recording device. Sourcing plan: retail shopping search: 3.5mm stereo audio cable.
- Biological Component: The lab requires live insects (e.g., crickets or cockroaches). Availability is seasonal or requires a biological supply house. Sourcing plan: retail shopping search: live crickets or Discoid cockroaches.