Linear Gain

The Linear Gain block scales the signal by the value specified in the text field.

1. Drag it into the workspace.
2. Right-click the block and select Add Algorithm > IC N >
   • Gain (slew)
   • Gain (no slew)
3. (Slew instructions mean better quality but at the expense of memory.)
4. Enter the desired scale factor into the text field.

For a sample design using this block, see the Basic DSP example.

The value you specify is in 5.23 format (5 bits for the integer, 23 for the decimal). The accepted values for this block are therefore in the range: -16 to 15.999.

This is the multiplication factor so therefore a value of “1” will not change the gain at all. The value of “0” will multiply by zero so it will mute the audio. The value of 2 will double the signal level (Add 6dB) Values less than 1 but greater than zero, 0dB and invert the polarity. A value of -0.5 will lower the signal by 6dB and invert the polarity. The value of -1 will only invert the polarity.

You can choose a slew or no-slew algorithm. Using slew RAM gradually ramps the signal from original to target value, while using no-slew RAM jumps the signal immediately.

For more information on target/slew ram, see Target Slew RAM in the Basic Sigma DSP Architecture book section of this wiki.