You are right. This is what I have in the logfile:
2015-01-22 19:41:06,832 - WARNING Found alsamixer configuration errors, the extension has been automatically disabled:
2015-01-22 19:41:06,835 - WARNING alsamixer/control must be set.
2015-01-22 19:41:06,837 - WARNING alsamixer/card must be set.
2015-01-22 19:41:06,840 - WARNING Please fix the extension configuration errors or disable the extensions to silence these messages.
2015-01-22 19:41:11,149 - ERROR Did not find unique mixer "autoaudiomixer". Alternatives are: software