Turn a direct instrument recording into an amp recording. The signal passes a preamp curve, a bass/middle/treble tone stack, a presence shelf, and a speaker cabinet, in that order, which is the order the same stages sit in on a real amplifier.
Channels
Three preamp voicings, each with its own gain range and its own curve:
- Clean saturates gently and stays close to the input even at Drive 100. Use it for bass and for clean guitar that needs weight rather than dirt.
- Crunch is asymmetric, which is where the even harmonics of a single-ended valve stage come from. It is the setting for rhythm parts.
- Lead runs two smooth stages in series for a much longer gain range, so notes compress and sustain instead of just distorting.
Drive sets how hard the chosen curve is pushed. Because the curve is fed the signal scaled by its own running level, the control means the same thing regardless of how the file was recorded or mastered.
Bass, middle, treble, presence
The tone stack sits between the preamp and the shaping stage, which is where an amp puts it. Turning the bass up therefore drives the stage harder as well as adding low end, exactly as it does on the hardware. If a setting sounds louder as well as fuller, that is why.
Bass is a shelf at 100 Hz, middle is a bell at 650 Hz, treble is a shelf at 3.2 kHz. Each covers 12 dB in both directions.
Presence is a separate shelf at 4.2 kHz applied after the shaping stage, so it lifts the amp’s own top end rather than feeding more treble into the distortion. It runs from -6 dB to +9 dB.
Cabinets
A speaker is a band-pass with a personality. Each cabinet here is a high-pass, one bell, and a fourth-order low-pass, tuned to where the real thing stops:
| Cabinet | Low end | Top end | Lift |
|---|---|---|---|
| 1x12 combo | 95 Hz | 5.0 kHz | +4 dB at 1.7 kHz |
| 2x12 | 80 Hz | 5.6 kHz | +3 dB at 2.2 kHz |
| 4x12 | 75 Hz | 4.2 kHz | +5 dB at 1.9 kHz |
| 8x10 bass | 45 Hz | 3.2 kHz | +2 dB at 900 Hz |
The low-pass is fourth-order rather than second because a real speaker stops much harder than 12 dB per octave. A gentler slope leaves 10 kHz only 17 dB down, and a driven signal up there reads as fizz.
Use the 8x10 for bass. Its lower corner keeps the fundamental of a low E and its top end removes the string noise that a guitar cabinet would leave in.
Aliasing and latency
The curve runs at eight times the sample rate and is filtered back down. Applied at the source rate, a distortion this hard makes harmonics above Nyquist that fold back into the track as tones with no relation to the note played, and no setting removes them afterwards.
Oversampling costs 16 samples of latency, which is 0.33 ms at 48 kHz. The dry side of the mix is held back by the same amount, the preview delays its bypass path to match, and the export trims the leading delay, so the alignment is not something you have to compensate for.
Mix and output
Mix blends the amp against the untouched input. At 100 the dry signal is gone, which is normal for a guitar part. Lower settings are worth trying on bass, where keeping some of the direct signal underneath preserves the low end that the cabinet’s high-pass removes.
Output is the amp’s master volume and applies to the wet signal only. A driven setting with a boosted tone stack can easily leave the file above 0 dBFS, so pull it down until the meter stops holding at the top.