locust_grove_cemetery_v1.1.endl (17.5 KB)
- Left Knob (Dirt): Preamp Drive & Compression
- Middle Knob (Body): (Far Left = Huge/Bassy Resonance, Far Right = Tight/Trebly Articulation)
- Right Knob (Catacomb): A haunted echo chamber (Mix/Size/Feedback)
- Left Footswitch (Press): Instantly toggles between the Clean Channel (Blue LED) and the Overdrive Channel (Red LED).
- Left Footswitch (Hold): Toggles “Sympathetic Resonance” for a massive, thick pad-like undertone.
1. Dual Memory Banks (True Channel Switching)
This is actually two independent pedals in one. The Clean channel and Overdrive channel have their own isolated memory banks!
Set your Clean channel to a massive bassy resonance with lush Catacomb reverb, then tap the footswitch and dial in a screaming Overdrive channel with a tight treble tone and zero reverb. When you swap channels, the pedal instantly loads your saved parameters. If you reach down and turn a knob, it “catches up” and instantly overwrites that single parameter on the active channel.
2. Dual-Amp Stereo Architecture (The “Twin” Effect)
If you run this pedal in stereo (or on headphones), you are in for a treat. The engine splits the signal into two physical `TubePreamp` models.
The Right Amp receives a microscopic 20ms offset delay (the Haas effect) and is mathematically biased to crunch slightly differently than the Left Amp. The result is a massive, 20-foot wide “Wall of Sound” that sounds exactly like double-tracked studio guitars.
3. Boutique Signal Chain
We modeled an entire studio recording chain inside the engine:
- Modal Tone Synthesizer: The middle Body knob doesn’t just boost bass or treble; it uses 12 dynamically tuned Modal Biquad filters and a Diffuser to physically synthesize the “cabinet resonance” and depth of the tone from scratch. The filters are trained on actual instrument acoustic IR’s to not only simulate the bodies of the instruments sampled but to smoothly and dynamically interpolate any body size in-between.
- Tube Preamp & Rodent Fuzz: The Dirt knob sweeps from a pristine clean tone into a warm tube saturation (+15dB). If you switch to the Overdrive channel and crank the knob, the tube saturation seamlessly morphs into a hard-clipping Silicon Diode fuzz with a lowpass filter to roll off harsh high-end.
- Dynamic “Tight” High-Pass Filter: A dedicated filter tracks your Dirt knob to dynamically cut muddy bass out of the overdrive circuit.
- Optical Compressor: A built-in compressor keeps your dynamics studio-perfect.
- Catacomb Reverb: A 4x4 Feedback Delay Network (FDN) that perfectly emulates playing inside a giant stone chamber.
UPDATE: Parametric Body Reverb
This adds a major upgrade to the Body knob that completely changes how the tone engine works under the hood.
What Changed,
Previously, the Body knob was driving a comb-filter reverb alongside the modal filters. It sounded good, but it didn’t sound real. We went back to the original instrument impulse responses and performed Schroeder backward integration on each one, the same technique used by professional acoustic engineers to measure real rooms and concert halls.
We extracted 9 physical parameters from the reverb tails of each instrument body:
- RT60 — how long the cavity actually rings (spoiler: real instrument bodies are shockingly short, 17–37ms)
- Mean Free Path — the average time between internal wall reflections
- Reflection Density — how many bounces per second (a violin has 5,200/sec vs a double bass at 2,100/sec)
- Frequency-Dependent Decay — how fast lows vs highs die out (larger bodies absorb treble ~32% faster)
- Modal Density — how many resonant peaks exist per kHz
Every one of those parameters was curve-fit to a `log(value) = slope × log(body_size) + intercept` equation, which means the engine can now calculate the exact reverb characteristics of any body size, not just the four instruments we sampled. Turn the Body knob to 62cm and you get a perfectly interpolated instrument that has never existed — and it sounds physically correct.
The Logarithmic Knob
We also noticed the Body knob felt uneven — the bottom third barely changed, the top third changed too fast. This is because all the parameters follow power laws, so equal *ratio* changes in size produce equal tonal changes. We switched the knob from a linear mapping to a logarithmic one, so now every degree of rotation produces the same perceptual shift across the entire sweep. It feels buttery smooth from end to end.