Hey -can't find any service manual on this unit -does anyone know if you can set bias and dc offset on these? I opened it up and found a few trimmers -but without a schematic not going to mess around. I have 31 mv on the left and 61 on the right -I think I'd like to get those down a bit? found it in the recyclables and seems to run fine -I actually like it! replace the side panels with some real walnut and all looks good.