---
title: "ssp"
summary: "Guitar pedal circuit design and simulation. CLI and browser. Built on SpiceSharp."
external_url: "https://github.com/4esv/ssp"
links:
  - "https://github.com/4esv/ssp"
  - "https://github.com/SpiceSharp/SpiceSharp"
  - "https://github.com/4esv/ssp/blob/main/CHANGELOG.md"
  - "https://github.com/4esv/ssp/blob/main/docs/decisions/0008-versioning.md"
  - "https://github.com/4esv/ssp/blob/main/models/README.md"
  - "https://github.com/4esv/ssp/blob/main/docs/cli.md"
  - "https://github.com/4esv/ssp/blob/main/docs/web.md"
  - "https://github.com/4esv/ssp/blob/main/docs/README.md"
  - "https://github.com/4esv/ssp/blob/main/CONTRIBUTING.md"
  - "https://github.com/4esv/ssp/blob/main/AGENTS.md"
  - "https://github.com/4esv/ssp/blob/main/LICENSE"
  - "https://github.com/4esv/ssp/blob/main/THIRD_PARTY_NOTICES.md"
---

- Stars: 0
- Language: C#
- Updated: 2026-10-25
- License: MIT
- Topics: blazor, circuit-simulation, dotnet, guitar-pedal, spice

[GitHub](https://github.com/4esv/ssp)

ssp designs and simulates guitar pedal circuits.
It has two interfaces: a command line tool and a static web app.
Both interfaces use the [SpiceSharp](https://github.com/SpiceSharp/SpiceSharp) engine.

The command line tool and its file formats are stable from version 1.0.0. The web app is not released. It deploys from `main` and can change at any time.
See [CHANGELOG.md](https://github.com/4esv/ssp/blob/main/CHANGELOG.md) and decision record [0008](https://github.com/4esv/ssp/blob/main/docs/decisions/0008-versioning.md).

## Install

You need the .NET 10 SDK.

```sh
git clone https://github.com/4esv/ssp.git
cd ssp
dotnet pack src/Ssp.Cli -c Release -o artifacts
dotnet tool install --global ssp --add-source artifacts
ssp --version
```

The package contains the tool only. The models and the sample audio are in the repository.
They are not in the package.
Download one model into the same folder as your netlist:

```sh
curl -fsSLO https://raw.githubusercontent.com/4esv/ssp/main/models/opamp-tl072.cir
```

Write this line in your netlist:

```spice
.include opamp-tl072.cir
```

A `.include` path is relative to the netlist file. See [models/README.md](https://github.com/4esv/ssp/blob/main/models/README.md).

If .NET comes from Homebrew, `ssp` can fail. The error starts with:

```text
You must install or update .NET to run this application.
```

It also says `Framework: 'Microsoft.NETCore.App', version '10.0.0'`.
The system can find an old .NET in another folder first.
Set `DOTNET_ROOT` and run it again:

```sh
export DOTNET_ROOT="$(brew --prefix dotnet)/libexec"
```

## Five-minute tour

Run these commands from the root of the repository.

1. Run a circuit. `ssp run` prints the DC voltages, the small-signal (AC) frequency response, and the impedances.
   An AC analysis is linear, so it does not show clipping.

   ```sh
   ssp run circuits/fixtures/rc-lowpass.cir
   ```

2. Change a part with `--set`. Or run one part at several values with `sweep`.

   ```sh
   ssp run circuits/fixtures/rc-lowpass.cir --set R1=4k7
   ssp sweep circuits/fixtures/rc-lowpass.cir --set R1=1k,4k7,10k
   ```

3. Render audio through a circuit. `render` is a transient analysis. Use it to hear and measure clipping.

   ```sh
   ssp render circuits/library/fuzz-transistor-diode.cir --in src/Ssp.Web/Audio/riff.wav --out fuzz.wav
   ```

4. Open the web app at <https://ssp.aesv.io>. Draw a circuit, press Run, and play a clip through it.

## Documentation

- [docs/cli.md](https://github.com/4esv/ssp/blob/main/docs/cli.md): every command and option.
- [docs/web.md](https://github.com/4esv/ssp/blob/main/docs/web.md): the web app.
- [docs/README.md](https://github.com/4esv/ssp/blob/main/docs/README.md): index of all documents.
- [CONTRIBUTING.md](https://github.com/4esv/ssp/blob/main/CONTRIBUTING.md): how to contribute.
- [AGENTS.md](https://github.com/4esv/ssp/blob/main/AGENTS.md): commands and rules for coding agents.

The documents are also at <https://ssp.aesv.io/docs/>.

## License

MIT. See [LICENSE](https://github.com/4esv/ssp/blob/main/LICENSE) and [THIRD_PARTY_NOTICES.md](https://github.com/4esv/ssp/blob/main/THIRD_PARTY_NOTICES.md).