Cmnaround wrote:How is the active preamp in a Carvin DC400A similar or different than a unity gain buffer? Apparently the pickups are passive and the active mode is a pre-amp, which leads to my question- do I already have a unity gain buffer with this active preamp or is that something completely different?
gr8fulbluz wrote:to the best of m recollection ( which aint great ). The active mode is an on-board preamp which allows bass and treble boost and cut.
So I think it is similar in that it is a preamp boosting the passive signal from the pickup. But apart from that i am unsure and i dont think it is exactly the same.
Both of these sound exactly like the same type of onboard preamp that bass players often have installed. Even $200 basses commonly come with preamps and onboard EQs from the factory now, I'm not sure why only Carvin seems to think it's useful for guitar, it's pretty handy to have an EQ at your fingertips.
Comparing John Kahn's 77-78 tone to my Fender Precision with the preamp both bypassed and engaged with the treble and bass boost set to 0, the engaged mode is much closer to his tone, it really nails it nicely. Commercial onboard bass preamps were very rare at the time and aftermarket ones were non-existant, so I suspect he had a custom UGB installed similar to Jerry's.