Drive
How hard the amp-like preamp is pushed.
- Turn up More amp grit and compressed power-amp feel.
- Turn down Cleaner amp voice with clearer dynamics.
Pedals / Direct amp-in-a-box tone
Stage Direct
Direct amp-in-a-box tone · play-tested
seth — fish
seth@ninevolt:~$
Knobs
In the TUI each knob runs from low (left / 0%) to high (right / 100%). Start near noon, then nudge while you play.
High
Treble / presence of the amp tone.
- Turn up Brighter, more cut and air.
- Turn down Darker, smoother highs.
Bass
Low-end body.
- Turn up Thicker, heavier bottom.
- Turn down Tighter, less boom.
Level
Master output of the amp sim.
- Turn up Louder overall.
- Turn down Quieter overall.
Inspired by
Tech 21 SansAmp Classic (1989) — all-analog FET amp-and-speaker DI: preamp, push-pull power stage, speaker/mic response, 8 Character DIP switches, 3-position input voicing (Lead / Normal / Bass). Kurt Cobain ran SansAmp into Mesa live on In Utero; Ninevolt profiles use Stage Direct as the amp block after dirt pedals. Display name Stage Direct; four panel knobs map to SansAmp Drive / High / Bass / Level (Presence + Amplifier drive merged into Drive).
Not a distortion pedal — full amp sim with cab LP (DISTORTION_COMPARISON.md lists clip curve only). Pair with Green Screamer, Black Rat, Wool Wall, etc. before Stage Direct in chain.
Signal path
| Step | What it does | ||
|---|---|---|---|
| High-pass ~72 Hz | Sub rumble cut — hardware “Low Drive off” HPF region. | ||
| Soft input pad | `x / (1 + 2 | x | )` — tames hot upstream distortion before preamp. |
| Preamp + asymmetric clip | Drive → up to ~25× into tube_preamp (+/− tanh asymmetry). | ||
| Push-pull power amp | Drive × Level → tanh − cubic trim — odd-harmonic power saturation. | ||
| Bass shelf | Bass boosts/cuts ~160–300 Hz region. | ||
| Treble shelf | High lifts upper mids/treble before cab rolloff. | ||
| Speaker/cab LP | One-pole 2.1–6.6 kHz cutoff tracks High. | ||
| Level + clamp | Master 0.16 + level × 0.88, ±1 out. |
Simplifications
- Mono in/out — no XLR DI tap - Single-pole cab sim — no multi-stage speaker IR - No Character switches or input voicing on panel - True bypass (no engage ramp)