- I72 DI Input Amplifier
- Compact Instrument Input Unit with Hi-pass and Low-pass Filter for 3U frames
The I72 is a DI Input Amplifier with very high input impedance. In addition, the units accepts levels up to + 36 dBu.
- The instrument input is electronically balanced, however by using the BAL and GND LIFT switches the module will also accept unbalanced signals. The BAL switch disconnects the b - phase of the balanced input amplifier from ground. GND LIFT lifts the connection between the ground of the I72 and the Sleeve of the input socket. The symmetric input takes the ground potential of the connected device. This circuit is meaningful when connected instruments and instrument amplifiers are already grounded.
- The gain is determined by a stepper switch and has a range from -12 dB to 36dB. The electronically balanced input has an input resistance from > 200kOhm. The settings -12 dB and - 6 dB insert a passive pad, so that very high levels can be applied to input. With the -12 dB setting the input accepts more than + 36 dBu which is equal to about 65 volts. A direct connection of the DI Input Amp to the output of any power amplifier is therfore possible.
- Special filter circuits that have no negative effects on the frequency and phase performance are used for an effective oppression of HF interference. High-pass and low-pass filters are integrated in the device and are turned on by the switch FILT.
- The high pass filter has a slope of 24dB per octave and a range of <20Hz to 600Hz. The low-pass filter has a slope of 12dB per octave and a range of >25kHz to 2kHz. A LED chain with 4 LED's indicates the output's level.
The output of the DI input amp is electronically balanced or is implemented balanced and floating.
Balanced and floating output