I did this to just show the icon and increase its size:
MPVolumeView *volumeView = [[[MPVolumeView alloc] initWithFrame:CGRectMake(255, 12, 30, 25)] autorelease];
volumeView.showsVolumeSlider = NO;
volumeView.showsRouteButton = YES;
volumeView.transform = CGAffineTransformMakeScale(1.5, 1.5);
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