RME OCTAMIC II [17/32] Line out

User’s Guide OctaMic II © RME

10.2 Line Out

The 8 short circuit protected, low impedance and servo balanced line outputs are available as

(stereo) 1/4" TRS jacks. The electronic output stage is built in a servo balanced design which

handles monaural and stereo jacks correctly.

The pinout follows international standards. Tip + or hot, ring – or cold.

To maintain an optimum level for devices connected to the analog outputs, the OctaMic in-

cludes a switch which allows to change the reference level of all 8 outputs simultaneously.

The OctaMic II can generate a maximum level of +21 dBu without distortion. However, the CLIP

LED has been designed to act like the OVR LEDs of the ADI-8 series. It lights up 2 dB before

the reference level selected on the back of the unit, plus a headroom of 9 dB, is reached. At Hi

Gain the LED lights up at +17 dBu output level, selecting +4 dBu it lights up at +11 dBu, select-

ing –10 dBV it lights up at 0 dBV.

Setting Reference Clip LED True Clip ADC Level

Hi Gain +19 dBu +17 dBu +21 dBu -2 dBFS

+4 dBu +13 dBu +11 dBu +15 dBu -2 dBFS

-10 dBV +2 dBV 0 dBV +4 dBV -2 dBFS

This also means that the CLIP LED lights up 4 dB before the OctaMic II actually reaches the

maximum level. Such an additional headroom is considered to be useful in real world operation.

The chosen reference level has no meaning for the digital outputs. The AD-conversion is de-

signed for a level of –2 dBFS as soon as the Clip LED lights up.

Selecting +4 dBu the output signal is attenuated by 6 dB, so for the same output level the ampli-

fication has to be increased via GAIN. With this trick the OctaMic reaches the maximum signal

to noise ratio on +4 dBu based inputs (like our ADI-8 series), because microphone preamps

have better EIN values at higher amplification. In case of an extreme recording situation, where

the gain of the OctaMic is no longer sufficient, selecting Hi Gain will again provide the highest

amplification possible.

The same is true and even more efficient at –10 dBV. In this case the output level is reduced by

around 14 dB – the same happens to the basic noise of the unit!