Originally Posted by Mr Singh
Good advice above, I use SMD DD-1 (I sell/import these) which is infact little better than a oscope at picking up distortion. Multimeter or scope won't find that, let alone a dodgy RCA cable.
Sounds interesting, I had 20 years in the business been out of it for 9 years or so now it was just down to my acute hearing then
I would expect there's lots of new tools and gadgets to help out now.