You cannot set the EQ on an SVT to be flat. I much prefer the Fender/Marshall style tone stack or Baxendalls. I'm aware that the Fender type of tone stack also won't get totally flat, but it's more pleasing to my ears than the "modern Ampeg" stacks. The older amps (B-15, etc.) sound fine. It's a different design.
So the part that I probably don't like about the preamp is based around this:
Yes, I play to a vinyl audience! Graphic EQ fallen from vogue? Like on the SVT 4 Pro? (a.k.a 400+ wannabe) lol
So the amp has a baked in EQ curve (see top curve below) that I don't care for. See the report below to show that you can't get a flat response no matter how you try. But that's why it sounds like an SVT.
So when I plug my bass into either most solid state amps, or my Trace, Mesa or Hartke, it still sounds like my bass when it's direct. Each amp has a certain flavor, but It still sounds like my bass. That's what my bass sounds like, and what I want to retain, while adding the oomph that an amp provides.
When I plug into an Ampeg, with the exception of a B-15, I don't hear my bass. I hear that preset EQ that Hughes designed into the amp. And I really dislike that sound.
I'm aware that other people want the sound that the amp provides.