Re: Advice on transformer hum Reply #25 – 2018-01-07 17:48:44 Arnold - thanks for the more technical explanation. Do you think that a DC blocker may help? Or any other remedy? Rotareneg - I have tried pressing on the case. I have tried removing the case and pressing on the transformer or PCB. No changes.Today I tripped all the switches on our consumer unit and left only the ring which contains the DAC open, switching off everything else on the ring to see if any other household appliance may be exacerbating it. No change unfortunately with the hum!