Modular Rack

The Modular Rack is a free-patching playground. Drop devices onto the rail, drag cables between jacks, and route audio or CV anywhere you like. Every Forge Steel synth is also a rack module — you can mix flagship voices with simple utilities in one patch.

• Nodes are devices. Each lives in a vertical strip on the rail with its faceplate, knobs, and jacks.
• Jacks are inputs and outputs. Audio jacks carry sound; CV jacks carry modulation values (pitch, gate, cutoff, gain).
• Cables connect an output to one or more inputs. Click an out, then an in. Click a connected cable end to detach.
• Voltage ranges — CV is normalized to bipolar (-1 to +1) unless a target expects a specific range (e.g. v/oct uses 1 V per octave; gate reads anything above 0.5 as on).

The default library. Forge Steel devices are documented in detail under Instruments — here we focus on their rack ports.

Build a basic monosynth from scratch — about a minute, all default devices.

1. 1
   Add an Oscillator
   Open the Device Library, drag Oscillator onto the rail. Pick a saw wave and set pitch to A3 (220 Hz).
2. 2
   Add a Filter
   Drag Filter next to it. Cable Oscillator out → Filter in. Choose LP mode, cutoff around 800 Hz, Q ~0.4.
3. 3
   Shape it with an Envelope
   Drop an Envelope. Cable Filter out → Envelope in. Set A=5 ms, D=200 ms, S=0.6, R=300 ms.
4. 4
   Send to Output
   Drop an Output. Cable Envelope out → Output in. Click Gate All in the toolbar — you should hear a plucky saw note.
5. 5
   Add movement with an LFO
   Drop an LFO, rate ~1 Hz, depth 30%. Cable LFO out → Filter freq. The cutoff now sweeps under the note.

Macros are eight assignable knobs on the rack toolbar. One macro can drive many destinations at once with per-target depth and curve — perfect for performance moves and quick automation.

1. Click Learn on any macro knob. It glows.
2. Touch the parameters you want to control — knobs in any rack device. Each tap adds a target with default depth.
3. Click Done. Twist the macro: every learned target moves together.
4. Open Macro Target Editor to tweak per-target depth, invert direction, or set a custom curve.

Two diagnostic devices that read any audio in the patch without affecting the signal — drop them anywhere and tap into a cable.

• LiveScope — oscilloscope view of the tapped signal. Useful for checking waveform shape, clipping, and LFO speed.
• PeakMeter — fast peak + RMS readout with hold-peak indicator. Use it before the Output to keep levels under 0 dBFS.

• Freeze renders the entire rack to a sample in place. CPU drops to near-zero; you can keep playing the frozen audio while you build the next patch. Unfreeze to restore the live graph.
• Presets live per-device — every faceplate has a preset bar. Forge Steel presets are shared with the standalone instrument.
• Save / recall patches stores the full graph (devices, cables, knob positions, macros) under your account. Patches sync across devices.

• Voices stack up fast. Each Forge Steel module is polyphonic — heavy unison + long releases is the #1 cause of CPU spikes.
• Freeze idle racks once you've committed to a sound. Live editing of twelve unfrozen racks at once will glitch even on a fast machine.
• Audio feedback loops are silenced with a one-block delay — useful for Karplus-style patches, but expect a sample of latency.
• Mobile (Forge Pocket) caps simultaneous racks at four. Open more and the oldest is auto-frozen.