User`s guide

16
User’s Guide OctaMic II © RME
10. Analog Inputs / Outputs
10.1 Mic / Line In
The OctaMic has 8 balanced Mic and Line inputs via 1/4" TRS (stereo) and XLR combo jacks
on the rear panel. The electronic input stage is built in a servo balanced design which handles
unbalanced and balanced signals correctly, automatically adjusting the level reference.
XLR
The pin assignment follows international standards. With XLR, pin 2 is + or hot, pin 3 is – or
cold, pin 1 is ground. Pin 1 is connected to the chassis directly at the socket (AES48).
When using unbalanced cables be sure to connect pin 3 (-) to 1 (ground). Otherwise noise
may occur, caused by the unconnected negative input of the balanced input.
The OctaMic II offers an adjustable amplification from +6 dB up to +60 dB. This equals a sensi-
tivity of +14 dBu down to –40 dBu, referenced to full scale of the AD-converter.
The soft switching, hi-current phantom power (48 Volt) provides a professional handling of con-
denser microphones. The usage of a hi-end integrated circuit (That 1510) guarantees out-
standing sound quality, lowest THD, and maximum Signal to Noise ratio in any gain setting.
The OctaMic II's 'overall' amplification from analog input to analog output depends on the ana-
log output reference setting. The EIN is not affected by this setting, since the S/N ratio scales
1:1 with the output amplification.
The input impedance is 2 kOhm.
TRS
The pin assignment follows international standards. With TRS, tip is + or hot, ring is – or cold.
When using unbalanced cables with stereo TRS jacks, the 'ring' contact of the cable's jack
should be connected to pin 1 (ground). Otherwise noise may occur, caused by the uncon-
nected negative input of the balanced input.
The TRS jacks have a fixed level attenuation of 7 dB. Based on the adjustable amplification
from +6 dB up to +60 dB, the sensitivity is +21 dBu down to –33 dBu, referenced to full scale of
the AD-converter. Therefore the TRS inputs are true full level Line inputs, and the unit can also
be used as Line amplifier.
The TRS jacks are free of phantom power. The unbalanced input impedance is 5 kOhm.