F_EFX1

F_DELAY & F_REVERB combined in a tiny bundle to fill your need for lush sounds, and your chance to get them separate from the full F_SYN bundle.

F_DELAY — Flexible Stereo Delay Effect Engine

Overview:
F_DELAY is a feature-rich, stereo delay module for Voltage Modular, offering smooth control over timing, feedback, filtering, and stereo imaging. With 10-second delay buffers, color filtering, and modulation inputs, it’s designed for everything from subtle echoes to complex rhythmic effects. Advanced internal signal processing ensures high-quality output, while custom controls provide precise tweakability.

Main Features:

• Up to 10 seconds of delay time per channel (48,000 samples at 48kHz)
• Individual controls for Delay Time, Feedback, Wet Mix, Groove, Color, and Output Level
• Stereo signal path with pan positioning for the delay return
• Built-in color filter per channel to shape delay tone (darker/warmer echoes)
• Smooth parameter transitions using custom smoothing filters
• Soft-clipping to prevent distortion artifacts
• Modulation inputs for delay parameters (e.g., feedback, pan, color)
• Toggle button to activate/deactivate delay effect in real time

Controls:

• Delay Time: Sets the delay length (1 ms to 10,000 ms). Skewed for fine control at short times.
• Delay Feedback: Controls how much of the delay output is fed back. Higher values result in longer trails.
• Delay Color: Adds filtering coloration using a dedicated filter; negative values dampen highs.
• Delay Wet: Mix between dry signal and delay return. 0 = fully dry, 1 = fully wet.
• Delay Groove: Acts as a time multiplier/divider for delay modulation, adding rhythmic feel or swing.
• Delay Out: Master output level of the delay return. Set between 0 and 2× gain.
• Delay Pan: Stereo pan for the delay return; 0 = full left, 1 = full right.
• Delay Toggle: Enables or disables the delay effect. Bypasses internal delay DSP when off.

Audio I/O:

• Inputs: Stereo input jacks (L/R), plus additional modulation inputs (up to 5)
• Outputs: Stereo delay return, automatically summed to mono if only one output is connected

Signal Processing Architecture:
F_DELAY uses two large ring buffers for the left and right channels, allowing delay times up to 10 seconds. Audio is processed through a custom smoothing engine (R_SmoothKnobVal) to prevent clicks and artifacts when changing parameters. Each channel is filtered using R_ColorFilter, which emulates analog-style high-frequency damping. Delay feedback is controlled with soft-clipping (softClip()) to maintain audio integrity even under high gain conditions.

Tips & Tricks:

• Use Delay Groove to apply swing or rhythmic offset to delay repeats.
• Turn up Delay Color for vintage/analog-style degradation on echoes.
• Modulate Delay Pan to create moving, stereo echo effects.
• Increase Delay Feedback and use short delay times to create comb filtering or flanger-like effects.
• To simulate slapback delay, set Delay Time to under 100ms and Wet to 0.3–0.5.
• Disable Delay Toggle for dry-through signal, useful when automating effect activation.

Internal Modules & Helpers:

• R_SimpleRingBuffer — Manages delay buffers with support for linear interpolation
• R_ColorFilter — Implements dynamic coloration/filtering for echoes
• R_SmoothKnobVal — Ensures smooth transitions between knob values
• softClip() — Limits feedback values to prevent distortion

Use Cases:

• Classic delay effects: echoes, slapback, doubling
• Experimental feedback loops with colored filtering
• Time-based modulation effects via external CV (e.g., LFO to feedback)
• Stereo delay imaging and rhythmic echo sculpting

F_REVERB — Rich, Modulated Stereo Reverb Processor

Overview:
F_REVERB is a lush, stereo reverb module for Voltage Modular, designed for musicality, depth, and flexibility. Using the internal R_Galactic engine and precision smoothing for modulation parameters, it delivers a highly dynamic, modulated reverb with wide tonal control. From ambient wash to rhythmic spatial patterns, F_REVERB responds smoothly and musically, making it ideal for both subtle space and immersive effects.

Main Features:
• True stereo processing with pan control
• Smooth modulation on reverb parameters via CV
• Galactic reverb engine with time, brightness, feedback, and detune shaping
• Independent wet level, dampening, and output gain
• On/off toggle for quick reverb activation
• CPU-efficient with smart input handling

Control Overview: