FR Pre-Amp box

Bassel cut off frequency

• 118 Hz

Gain

Blue Switch (input)：

1. Preamplifier | on: gain = 24.3; off: gain = 218
2. Preamplifier on or off
3. GND on or off
4. Bessel: if on, preamplifier output to Bessel filter input (gain=1.95)

Red Switch (output)：

1. Additional amplifier output
2. Connect Bessel filter to additional amplifier input
3. Bessel filter output
4. Preamplifier output

• So, we always use 218 * 1.95 * 4 = 1700.4

Operate manual

• Under Constriction