ssp

Guitar pedal circuit design and simulation. CLI and browser. Built on SpiceSharp.

Stars	Language	Updated	License
0	C#	2026-10-25	MIT

Topics: blazor, circuit-simulation, dotnet, guitar-pedal, spice

GitHub

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 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 and decision record 0008.

Install

You need the .NET 10 SDK.

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:

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

Write this line in your netlist:

.include opamp-tl072.cir

A .include path is relative to the netlist file. See models/README.md.

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

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:

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

Five-minute tour

Run these commands from the root of the repository.

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

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

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

Render audio through a circuit. render is a transient analysis. Use it to hear and measure clipping.
```
ssp render circuits/library/fuzz-transistor-diode.cir --in src/Ssp.Web/Audio/riff.wav --out fuzz.wav
```
Open the web app at https://ssp.aesv.io. Draw a circuit, press Run, and play a clip through it.

Documentation

docs/cli.md: every command and option.
docs/web.md: the web app.
docs/README.md: index of all documents.
CONTRIBUTING.md: how to contribute.
AGENTS.md: commands and rules for coding agents.

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

License

MIT. See LICENSE and THIRD_PARTY_NOTICES.md.