Octavian, my comment after reading the Underwood material is that it's pure hogwash. Those Denons and most other modern players provide audibly flawless reproduction of discs. If there was any modification(especially involving a tube analog output stage)which actually resulted in an audible difference it would by definition be a degradation of the result achieved by the audio engineers who originally designed the player. This is yet another instance of the urge to tweak in an increasingly untweakable world.
