Volume Resets automatically after Yosemite

After upgrading to Yosemite 10.10, my system volume keeps resetting itself to a very high level. I turn it down, play one song on iTunes, then when I select another song, the volume is up over half. This happens on other apps besides ITunes. I use a Apogee Quartet USB interface for audio playback, and Yosemite keeps changing the speaker volume. I've tried changing system preferences but no luck. Thanks for any suggestions. This did not happen before Yosemite.