Theres a fair bit of division in the group about whether all stainless-steel construction (or at least "no copper") is to blame or not. Many like yourself have absolutely no problems with it. But theres been a handful who have found that adding some copper did make a difference. I don't know what the absolute truth is about it, but figure that its something easy to try if having problems.
As pointed out in http://homedistiller.org/materials.htm#copper
theres a fair bit of good that copper can do in terms of binding some of the offensive smells/flavours. Maybe you're doing something different (good) with your wash in the first place to not generate the flavours.