My Beogram 4002 has “developed” a disturbing deep-bass harmonic feedback. The sound builds and builds to a frightful level unless the volume is immediately lowered.

My first thought was the suspension was not completely unlocked. Some adjustment was needed, but this was not the problem.

Then I noticed after a prior slight adjustment of the dustcover had rendered the black box that covers the arms to slightly touch the back of the dustcover. OK, simple solution… but not so fast, adjusting the dustcover reduced the harmonic feedback, but did not eliminate it.

Out of pure frustration, I decided to isolate the turntable with heavy padding under the turntable and problem “solved.” Dealt with would be more accurate. The padding looks tacky and only masks a real problem.

Any idea for what might be causing this major bass feedback?

The Beogram 4002 sits atop a massive McIntosh consol and is completely separate from the speakers that flank the consol.

Many thanks.

Jeff 

Jeff