| Signal Flow
diagram of an expander. |
| Ü An amplifier with variable gain |
| Ü Gain ranges from -inf to 1, never above 1, or unity gain |
| Ü As input signal level drops amplifier gain decreases, making low-level signals even lower in level at the output! |
The expander is essentially an amplifier with a variable gain control. The gain is never greater than one, and it is controlled by the level of the input signal. When the signal level is high, the expander has a unity gain, and when the signal level drops, the gain decreases, making the signal even lower. The basic structure of an expander is as follows:
| Signal Flow
diagram of an expander. |
 |