Is this what a good preamp does?

I just completed a DIY tube preamp using John Broskie's Tetra phono and Aikido line stage PCBs. It replaced a solid state Parasound 2100 although I'm still using the SS Parasound 2250 amplifier to drive my speakers. I haven't changed anything else in my system (yet).

My turntable is a modified Technics 1200 with AT150MLX cartridge.

I have found that there is now much more detail coming from the vinyl playback. I can hear the bow being drawn across strings... . There is, however, more groove noise apparent on older records.

As I haven't had a chance to audition high-end equipment, I was wondering if what I'm hearing is approaching the sound that a quality component allows through? Does my new preamp have - for example - a less restricted pathway for the sound or perhaps does higher gain in the phono stage (50db versus 37 db) amplify the signal that was always there?
The wider you open the window the more dirt flies in. Hearing more grove noise is the downside of more interior detail; that said the AT 150 is not the easiest cartridge to align, you might check to see if you can reduce the groove noise by changing SRA or azimuth.
Mr S is correct. The more transparent a component, the less it masks the negatives, contained in the source material, or whatever is upstream. Inferior components tend to impose their sonic footprint on whatever passes through them, and make everything sound the same. Think of yourself as viewing a garden, through a series of glass panes. Your view will only be as sharp and clear, as the dirtiest pane of glass allows.
Rodman, great analogy with the panes of glass.Very cool!