Hello,
I bought a Stereomour second hand a year and a half ago and I realized that the hiss was a little too loud but I thought that is the way it is suppose to work. Reading this post I realized that I needed to check the LM431s which I did and they are indeed the WS ones. Is thre any chance you might have a good set lying around? I was planning on ordering 2 bottlehead badges so if you still have a pair of LM431s can you please through them in as well. I can pay for them there is no issue there.