Rega p3 and Yamaha AS1100


New rega p3 and Yamaha AS100.  Playing moderate volume between 8 to 10 o'clock runs great good quality sound. As soon I set to 11 o'clock volume on my amp, speaker start to produce chopper and vibration sound. Checked the tracking force and balance of the TT and they are ok. Run my amps on my Spotify feed at high volume and it's ok. Checked table vibration and it's ok.  I am stuck and don't know we're to start. Any help out their will be greatly appreciated. 
mario2016
Exactly what I had when TT was next to the speakers! Thats how I check that my table vibration is Not OK. 
@mario2016

The problem is called acoustical feedback. If you have a dustcover,remove it and see if that works. If not try using one speaker at a time to find which one is causing the feedback problem. Some non suspended turntables like the Rega have this problem.
@  yogiboy ,Yes I do. I will test this tomorrow. May I ask why dustcover will give acaustical feedback?