FRITZ!Fon C4 Service - Knowledge Base

FRITZ!Fon C4 Service
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Using a headset

In addition to using the "hands-free calling" function to make calls with your FRITZ!Fon, you can also use a headset with it. The telephone has a 3.5 mm stereo jack on its right side.

Fig.: Assignment of the 3.5 mm jack (stereo)

Fig.: Assignment of the 3.5 mm jack (mono)


You can use any commercially available headset for mobile telephones with an earphone impedance of 32 Ohm and a microphone impedance in the range of 800-2200 Ohm (+/- tolerance). You can use stereo or mono headsets with the connector pin assignment shown above. The mechanical protection of the connector should be no more than 7 mm in order to ensure good contact.

However, AVM successfully tested the following headset models. Since AVM has no influence on technical changes made to these accessories, we cannot give a general performance guarantee:

  • Sennheiser SC 232/262 and SC 632/662 used with the suitable adapter GSM-ADP-CBB01 (without answer/end button) or CMB 01 CTRL (with answer/end button)

To our knowledge, iPhone headsets do not work with a FRITZ!Fon.