I recently bought 5 x AML1's from PMC in the UK - one has a faint buzzing noise emminating from the HF Drive that becomes louder when you touch the HF Tilt button when the equalizer is in play. I am being strongly told they are under a ship back to base warranty only - however I feel I should not have to pay for shipping as the problem was there from the start. Is it me or after spending over £10,000 should I not expect a more caring approach?