User's Manual

User’s Guide ADI-2 DAC v2.2 © RME

19.5 IEM Out

This output via stereo mini-TRS is optimized for the use of high-quality IEMs, but generally

works very well with portable headphones that do not require high power or voltage. The IEM

output might be the world's lowest-noise headphone output at an output impedance of less than

0.1 Ohm, and without resorting to tricks such as a voltage divider with resistors at the output.

Maximum output level is -0.5 dBu (-3 dBu with Volume set to +2.5 dB), equalling 0.73 Vrms.

The noise floor at extremely low -124 dBu(A) stays inaudible even with the most sensitive In-

Ears. At full output level and a load of 16 Ohms, distortion is lower than -110 dB or 0.00039 %.

SETUP – Options – Phones / DSD – Mute Line offers an option to turn off the rear outputs as

soon as a phone is plugged in. Default is vs. Phones, which means Mute when plugged.

Due to the very low output voltage and output power the IEM output does not need DC

protection, overload and short circuit detection.

19.6 Using more than one Output

If SETUP – Options – Phones / DSD – Mute Line is set to OFF, all three outputs will work

simultaneously. The Line out specifies all settings. Its EQ, Bass / Treble, Loudness etc can be

heard on Phones and IEM output. Since the device only has one DA converter, it naturally can

not output three different digitally processed stereo signals.

The Line volume setting affects all at the same time as well. By manually selecting Hi- and Lo-

Power on the Phones output, it can be brought to a suitable base level.

If Auto Ref Level is active on Line Out, there will be jumps in level when the Ref Level is

exceeded or below on the Phones output. This is not a mistake - there are no hardware levels

in steps of 6 dB on the phones out, so you can hear the volume changes of the DSP from the

Line out without the Line Out Ref Level compensation. To avoid this do not use Auto Ref Level

in such a multi-output application.

If Auto Ref Level is active on Line Out and Phones, the feature will be disabled on Phones. For

a similar reason - otherwise there is a very unpleasant increase in volume of 15 dB on the

Phones output when switching from Lo to Hi Power.

When using both headphone outputs, the output specifies the settings that will be used

(plugged in) first. The device also remembers this when switched off and on again.