Which headphones are you using?
Other owners with the CSP2 + Taboo + HE-500 find that the CSP2 pre-amp delivers more punch to the HE-500 than just the Taboo alone? I can drive the HE-500 fairly loud but for some recordings the levels are lower and the Taboo would benefit from a pre-amp.
Does anyone use a non-Decware pre-amp with the Taboo? Blasphemy I'm sure.
I have the CSP2+ TABOO combination. Totally black background. My Taboo has the vcaps and sometimes after warming up really well, I get a glimpse of what they can do. I have about 50 hours on em now. I just changed the rectifier tubes to the something something GT's which the amps were designed for, and they opened up the detail. I like the visual effect with the smaller GT tube too. I would highly recommend the CSP2+ for anyone with a Taboo. The volume control is smooth, and I like the input and output gain controls. 5y3GT rectifiers, Sylvania USA, $30 each.