To put it into perspective, it's been a long time since I heard a bad sounding piece of high fidelity equipment. I've never heard a bad sounding one that measured well.
I just don't have the osilliscopes or gear to actually measure what I hear. I can run Spectraplus, as I do for EQing my sub, but I don't know why I'd do that for a preamp? As for hearing a bad sounding piece of gear, I guess that is all relative to me. A new piece of gear could sound bad or better than your most previous piece of gear depending on what that last piece of gear was... many folks like the sound of their B&K Ref 30s. I found it veiled and rolled off sounding. IMO, we both are right.