Hello, I just purchased a Yamaha A1 integrated amp. While the line stages sound great I'm noticing some problems in the phono stage. 1. The gain levels to achieve slightly loud sound output means I am turning the knob past 12 o'clock each time. (High output MM cart used). I have efficient altec bolero horn speakers too, so I know they can get very loud with 70wpc amps. 2. The oscillations in the woofer cones look terrible, heavy shaking in the woofer cones. Other receivers I have used with the same turntable, arm, cart have not produced this level of shaking, it looks like my speakers might pop out of the cabinet, and the volume is not that loud. Engaging the subsonic filter does not help much at all. 3. The left speaker eventually mutes if I turn it up past decently normal volumes, as in the bass and treble output is almost gone, and the speaker shaking stops completely. It just seems like this amp has no control or authority over the speakers when engaged in phono. Apparently this amp was throughly recapped and serviced in 2011. Any input would be greatly appreciated!