I had similar noise with Transcendence Ten. First, switch L/R tubes to see if the noise follows the tubes in order to confirm that a tube is the source. A tube retailer suggested tapping tubes gently but firmly with eraser on pencil to settle out any flakes on interior of tubes. What the hey, that's a freebie!, I thought. This actually helped mine but only for a few hours of play. I bought the T Ten used from AVA and was unsure of tube age, so ordered replacements from AVA and the what do you call 'em, microphonics, are gone. Under $100