Low-quality digital sampling
| Headroom | Peak clipping threshold |
| Quant | Bit depth (typically 8 or below for "telephone" quality) |
| Rate | Sample Rate (turn control to left or right for different sound characters) |
| Post Filter | Low-pass filter to muffle the distortion produced by the previous two controls |
| Non-Linearity | Additional harmonic distortion "thickening" (turn control to left or right for different sound characters) |
| Output | Level trim |