Fredenstein F676 - Manual (Page 6)

Advanced Audio Sub Menu:
Input Impedance:
In general the 1000 Ohms setting will work the best with most microphones. Some dynamic
and ribbon microphones however require a lower termination to exhibit their optimum
frequency response. In this case, please select the 200 Ohms option.
Low Frequency Roll-Off:
To avoid recording unwanted low frequencies (rumble), a high-pass filter can be inserted.
The three settings are:
OFF
: no high-pass filter (full frequency response)
30Hz : all frequencies above 30Hz are amplified
60Hz : all frequencies above 60Hz are amplified
Polarity:
Due to placement of microphones sometimes the polarity (phase) needs to be changed.
(An example would be a bottom microphone on a snare drum). In this case, select the
reverse polarity.
Muting:
The amplifier can be muted to avoid unwanted signals to come through.
Push-Pull versus Single-Ended Output Configuration:
The output stage can be changed from normal push-pull to single-ended mode. This will
change the sound characteristics. Values in between can also be achieved. Please note that
the output level in single-ended mode is 6 dB lower.
Fredenstein F676 Manual V1.1 July 18, 2014 Page 5