Pro Co Rat Schematic

This example uses the checked-in LiveSPICE fixture at tests/fixtures/schx/livespice-examples/Pro Co Rat.schx.

The fixture is useful as a conversion sanity check because it covers the parts of the pedal that are easy to lose in a schematic importer:

• X1 preserves the LM308 op-amp identity.
• D1 and D2 preserve the 1N914 hard clipping pair.
• Tone and nearby RC parts preserve the tone/filter network.
• Q1 preserves the 2N5458 JFET buffer.
• Distortion, Tone, and Volume preserve user-facing controls.

The SVG above is a compact schematic overview for docs. The source of truth is still the .schx fixture and the parsed CircuitDocument.

Convert the fixture

import { readFileSync } from "node:fs";
import {
  convertCircuitDocumentFile,
  parseCircuitDocumentFile,
  serializeCircuitJsonDocument,
} from "@vessel-dsp/core";

const source = readFileSync(
  "tests/fixtures/schx/livespice-examples/Pro Co Rat.schx",
  "utf8",
);

const document = parseCircuitDocumentFile(source, {
  filename: "Pro Co Rat.schx",
});

const { elements, warnings } = serializeCircuitJsonDocument(document);

const vdsp = convertCircuitDocumentFile(source, {
  inputFilename: "Pro Co Rat.schx",
  outputFormat: "vdsp",
  outputFilename: "Pro Co Rat.vdsp",
});

elements is official Circuit JSON suitable for downstream tscircuit tooling. warnings should be treated as caller-visible conversion diagnostics, not ignored.

VDSP source preview

The preview is intentionally excerpted from the generated .vdsp source so the page stays readable. The full output preserves every converted component, terminal, wire, and diagnostic emitted by the serializer.

schema: circuit-interchange/v2
metadata:
  name: ""
  description: ""
  partNumber: ""
source:
  format: interchange
  filename: "Pro Co Rat.vdsp"
components:
  - id: _1
    kind: label
    name: _1
    sourceTypeName: "Circuit.Label, Circuit, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"
    origin:
      x: 0
      y: -160
    properties:
      Text: "Pro Co Rat"
      Subtext: "https://www.electrosmash.com/proco-rat"

  # ... input, bias, gain, tone, and wiring entries omitted ...

  - id: D1
    kind: diode
    name: D1
    sourceTypeName: "Circuit.Diode, Circuit, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"
    origin:
      x: 100
      y: 150
    properties:
      Type: Diode
      Name: D1
      PartNumber: "1N914"

  - id: X1
    kind: opamp
    name: X1
    sourceTypeName: "Circuit.OpAmp, Circuit, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"
    origin:
      x: -150
      y: 100
    properties:
      Rin: "40 MΩ"
      Rout: "50 Ω"
      Aol: "300 k"
      GBP: "1 MHz"
      Name: X1
      PartNumber: LM308

  - id: Q1
    kind: jfet
    name: Q1
    sourceTypeName: "Circuit.JunctionFieldEffectTransistor, Circuit, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"
    origin:
      x: 490
      y: 200
    properties:
      Type: N
      Name: Q1
      PartNumber: "2N5458"

  - id: Tone
    kind: variable-resistor
    name: Tone
    properties:
      Resistance:
        raw: "100 kΩ"
        value: 100000
        unit: "Ω"
      Wipe: "0.5"
      Sweep: Logarithmic

Control panel from VDSP

Yes. Use extractPanel(document) from @vessel-dsp/core. Parse the .vdsp into a CircuitDocument, then extract the typed panel descriptor from that document.

import {
  extractPanel,
  parseCircuitDocumentFile,
} from "@vessel-dsp/core";

const vdspDocument = parseCircuitDocumentFile(vdsp, {
  filename: "Pro Co Rat.vdsp",
});

const panel = extractPanel(vdspDocument);

const controlIds = panel.knobs.map((knob) => knob.id);
// ["Distortion", "Tone", "Volume"]

For this fixture, the generated panel descriptor includes the three front-panel controls and the inferred audio ports:

{
  "knobs": ["Distortion", "Tone", "Volume"],
  "jacks": ["V1:input", "S1:output"],
  "switches": [],
  "leds": []
}

If the .vdsp source declares physical panel placement metadata, extractPanel() returns it as panel.placement; otherwise it only reports the inferred controls and ports.

Persist edited placement

When a UI lets the user drag an existing panel element, use movePanelElement() to update the element’s physical.centerMm, then serialize the document back to .vdsp.

import {
  movePanelElement,
  serializeCircuitDocumentFile,
} from "@vessel-dsp/core";

const movedDocument = movePanelElement(vdspDocument, {
  faceId: "top",
  elementId: "tone-knob",
  centerMm: { x: 12, y: -18 },
});

const movedVdsp = serializeCircuitDocumentFile(movedDocument, { format: "vdsp" });

The helper preserves existing fabrication metadata such as drillDiameterMm, partProfileId, and locked. If the element exists but has no physical block yet, the helper creates one with units: "mm".

What this proves

The example proves source-format parsing and Circuit JSON export. It does not claim LiveSPICE audio simulation parity.