User Manual

User’s Guide ADI-2 Pro - v 1.91

Dual Phones Mode required

Phones output PH 1/2 is considered an additional output for

two specific cases: usage of two headphones and balanced

phones operation. Therefore plugging in phones into output

PH 1/2 brings up a warning that this output is coupled to the

rear outputs, and should only be used if required.

PH 1/2 stays deactivated until Dual Phones mode has been

activated via SETUP.

Overload / Short detected

An internal overload can be caused by too high output levels

and too low load impedance. A short circuit in the TRS plug

will also trigger the overload detection. In such a case the

relay will permanently disconnect the phone from the Extreme

Power output stage. If the phones plug is removed and

plugged in again after one second, the unit will activate the

phones output again.

This scheme has been introduced to force the user to check

cabling and connection. For example, a TRS plug not fully

inserted might stay unnoticed but can cause a short circuit.

DC detected

DC detection is crucial to prevent the sensitive phones drivers

from being destroyed by inaudible currents flowing through

them. As the ADI-2 Pro is fully DC coupled from DAC to

phones output, a digital full scale signal with 0 Hz would

produce up to 15V DC at the outputs, and destroy any

attached phone immediately. In case the power output stage

fails the same could happen. Therefore the phones outputs

will switch off with 1.8V DC detected.

Power Fail

In case the operating voltage drops below 9.3V the internal

power supply of the analog I/Os is switched off (overcurrent

protection). However the digital part will operate even with

only 5V. Therefore connecting a wrong power supply could

pretend a fully working unit - which just doesn't receive or

emit any audio. This warning screen informs about the

undervoltage problem.

Internal Error

During power-on the unit performs a self-test. When this test

fails USB will be deactivated, with record and playback no

longer functional. In such a case please contact your local

RME distributor.