To understand soft tube saturation, you first have to understand how vacuum tubes (valves) behave. Unlike digital clipping, which "squares off" a waveform abruptly (causing harsh, unpleasant artifacts), vacuum tubes handle loud signals gracefully.
| Control | Range | Default | Description | |---------|-------|---------|-------------| | | 0 – 100% | 35% | Input gain into the tube stage. Increases harmonic density and saturation. | | Output Trim | -24 dB – +24 dB | 0 dB | Post-saturation gain compensation. | | Harmonics Mix | 0% (Clean) – 100% (Saturated) | 60% | Blends dry signal with saturated path. | | Tube Character | Smooth, Classic, Aggressive | Smooth | Selects bias point and harmonic emphasis. | | High-Freq Rolloff | On / Off | On | Engages a 6 dB/oct low-pass filter (starting ~8 kHz) to reduce fizz. | | Auto Gain | On / Off | Off | Automatically compensates output level to match perceived loudness. | soft tube saturation
When an audio signal pushes a tube toward its limit, the tube begins to round off the peaks of the waveform. This is known as . The result isn't a "fuzz" or "crunch" (unless pushed extreme), but rather a thickening of the sound characterized by: To understand soft tube saturation, you first have